Poly(lactic acid) (PLA) is a biobased and biodegradable plastic derived from natural resources. In this study, the degradation mechanism of PLA during hydrolysis was experimentally verified, and a computational strategy was constructed to predict its degradation behavior. The reaction rates and solid-state structure of PLA during hydrolysis were measured, and the hydrolysis behavior of the crystalline and amorphous phases was investigated. The results indicated that the molecular chains were randomly cleaved in the amorphous phase but were cleaved only on the folding surface of the lamellar crystals in the crystalline phase. Furthermore, the degradation behavior of amorphous and semicrystalline PLA during hydrolysis was modeled and simulated using the kinetic Monte Carlo method. The specific degradation behavior of the crystalline phase was described by considering the distribution of lamellar crystals and the dependence of the degradation rate on the molecular chain position. With this model, the molecular weight distribution and weight loss of PLA can be predicted. This study is the first to construct a degradation model based on a solid-state structure that can predict not only the average molecular weight but also the molecular weight distribution.
{"title":"Analysis of the hydrolysis behavior of poly(lactic acid) (PLA) and prediction of molecular weight distribution changes via the kinetic Monte Carlo method","authors":"Takanari Koike , Yosuke Muranaka , Yuta Okada , Aira Onishi , Taisuke Maki","doi":"10.1016/j.polymdegradstab.2025.111272","DOIUrl":"10.1016/j.polymdegradstab.2025.111272","url":null,"abstract":"<div><div>Poly(lactic acid) (PLA) is a biobased and biodegradable plastic derived from natural resources. In this study, the degradation mechanism of PLA during hydrolysis was experimentally verified, and a computational strategy was constructed to predict its degradation behavior. The reaction rates and solid-state structure of PLA during hydrolysis were measured, and the hydrolysis behavior of the crystalline and amorphous phases was investigated. The results indicated that the molecular chains were randomly cleaved in the amorphous phase but were cleaved only on the folding surface of the lamellar crystals in the crystalline phase. Furthermore, the degradation behavior of amorphous and semicrystalline PLA during hydrolysis was modeled and simulated using the kinetic Monte Carlo method. The specific degradation behavior of the crystalline phase was described by considering the distribution of lamellar crystals and the dependence of the degradation rate on the molecular chain position. With this model, the molecular weight distribution and weight loss of PLA can be predicted. This study is the first to construct a degradation model based on a solid-state structure that can predict not only the average molecular weight but also the molecular weight distribution.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111272"},"PeriodicalIF":6.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.polymdegradstab.2025.111273
Eiji Ishiko, Yasuhito Suzuki, Akikazu Matsumoto
Poly(dialkyl fumarate)s (PDRFs) with a poly(substituteda methylene) structure are highly transparent amorphous polymers with excellent heat resistance, mechanical, and optical properties. When optical polymer materials are used for electronic devices, both chemical and physical stability are required for the thermal properties of polymers. In this study, we conducted radical polymerization and copolymerization of dibornyl fumarate (DBoF) and diisobornyl fumarate (DIBF) with a symmetric ester structure as well as bornyl isopropyl fumarate (BoiPF) and isobornyl isopropyl fumarate (IBiPF) with an asymmetric structure to investigate the thermal and optical properties of the resulting PDRFs as the poly(substituted methylene)s including bicycloalkyl ester groups with a fixed molecular conformation in the side chain. It was revealed that the polymerization reactivity of the fumarates containing a bornyl group was higher than the fumarates including an isobornyl group. Monomer reactivity ratios were determined to be r1 = 0.83 and r2 = 0.92 for the copolymerization of DBoF (M1) and diisopropyl fumarate (DiPF, M2) while r1 = 0.54 and r2 = 1.60 for the system of DIBF (M1) and DiPF (M2). The thermal decomposition behavior of the resulting PDRFs depended on the geometric structure of the bornyl and isobornyl ester groups; for example, the onset temperatures of thermal decomposition were 306–320 °C and 240–269 °C for the Bo- and IB-containing PDRFs, respectively. The β-transition temperature also significantly increased from 64 °C for the diisopropyl ester of PDRF to 132 °C for the diborny ester. On the other hand, refractive index kept constant in a range of 1.46–1.48 for the Bo- and IB-containing PDRFs independent of the kind of a geometric structure and the contents. In order to clarify the thermal stability of the polymers, we investigated a mechanism for olefin elimination from the ester alkyl groups upon heating in the absence and presence of an acid, and discussed the effect of the geometrical structures, i.e., endo and exo configuration of the ester alkyl groups on the thermal decomposition mechanism. The aggregation structure of the polymer chains was also analyzed based on the results of wide-angle X-ray scattering (WAXS) analysis in the solid state to examine the relationship between the molecular packing and the physical properties of the PDRFs.
{"title":"Thermal stability and physical properties of poly(alkyl fumarate)s with Bornyl and Isobornyl groups as the geometrically isomeric esters","authors":"Eiji Ishiko, Yasuhito Suzuki, Akikazu Matsumoto","doi":"10.1016/j.polymdegradstab.2025.111273","DOIUrl":"10.1016/j.polymdegradstab.2025.111273","url":null,"abstract":"<div><div>Poly(dialkyl fumarate)s (PDRFs) with a poly(substituteda methylene) structure are highly transparent amorphous polymers with excellent heat resistance, mechanical, and optical properties. When optical polymer materials are used for electronic devices, both chemical and physical stability are required for the thermal properties of polymers. In this study, we conducted radical polymerization and copolymerization of dibornyl fumarate (DBoF) and diisobornyl fumarate (DIBF) with a symmetric ester structure as well as bornyl isopropyl fumarate (BoiPF) and isobornyl isopropyl fumarate (IBiPF) with an asymmetric structure to investigate the thermal and optical properties of the resulting PDRFs as the poly(substituted methylene)s including bicycloalkyl ester groups with a fixed molecular conformation in the side chain. It was revealed that the polymerization reactivity of the fumarates containing a bornyl group was higher than the fumarates including an isobornyl group. Monomer reactivity ratios were determined to be <em>r</em><sub>1</sub> = 0.83 and <em>r</em><sub>2</sub> = 0.92 for the copolymerization of DBoF (M<sub>1</sub>) and diisopropyl fumarate (DiPF, M<sub>2</sub>) while <em>r</em><sub>1</sub> = 0.54 and <em>r</em><sub>2</sub> = 1.60 for the system of DIBF (M<sub>1</sub>) and DiPF (M<sub>2</sub>). The thermal decomposition behavior of the resulting PDRFs depended on the geometric structure of the bornyl and isobornyl ester groups; for example, the onset temperatures of thermal decomposition were 306–320 °C and 240–269 °C for the Bo- and IB-containing PDRFs, respectively. The β-transition temperature also significantly increased from 64 °C for the diisopropyl ester of PDRF to 132 °C for the diborny ester. On the other hand, refractive index kept constant in a range of 1.46–1.48 for the Bo- and IB-containing PDRFs independent of the kind of a geometric structure and the contents. In order to clarify the thermal stability of the polymers, we investigated a mechanism for olefin elimination from the ester alkyl groups upon heating in the absence and presence of an acid, and discussed the effect of the geometrical structures, i.e., endo and exo configuration of the ester alkyl groups on the thermal decomposition mechanism. The aggregation structure of the polymer chains was also analyzed based on the results of wide-angle X-ray scattering (WAXS) analysis in the solid state to examine the relationship between the molecular packing and the physical properties of the PDRFs.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111273"},"PeriodicalIF":6.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.polymdegradstab.2025.111275
Lingzhi Wang , Hua Liu , Birong Zeng , Kaibin He , Yiting Xu , Conghui Yuan , Lizong Dai
The effective combination of flame retardant element and carbon dots for the development of epoxy composites with high mechanical property and low dielectric constant in the field of flame retardant material is still a challenge. Herein, the boron and phosphorus dual-element doped carbon dots (BP&NCDs) was synthesized using a simple Kabachnik-Fields reaction, and then incorporated into epoxy resin in different amount to prepare a series of EP/BP&NCDs composites. The optical, thermal stability, mechanical, dielectric and flame-retardant properties were tested by many techniques such as UV–vis spectroscopy, FL, TEM, TG, UL-94 and LOI e.g. It showed that the EP/BP&NCDs composites had favorable transparency, hydrophobicity, mechanical and dielectric properties, while maintaining the photo-luminescent properties. It was worth noting that the EP/3 %-BP&NCDs composite with only 3 % BP&NCDs addition exhibited significant flame-retardant properties with a UL-94 V-0 rating and a limiting oxygen index (LOI) of 31.3 %. Meanwhile, it led to obvious reductions of 34.9 %, 26.6 %, and 15.6 % in peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP), respectively. Furthermore, compared with pure EP, the EP/3 %-BP&NCDs composites enhanced the bending strength and impact strength by 32.3 % and 30.3 %, but reduced the dielectric constant and dielectric loss by about 40.0 % and 50.0 %, respectively. When EP/BP&NCDs composites were burned, a continuous and dense carbon layer was formed due to the synergistic action of phosphorus and boron in CDs. Overall the carbon dots (CDs) after surface modification could be applied in epoxy resin system for the achievement of multiple functional EP composites with good flame retardancy, mechanical and dielectric property at low addition, which is helpful to provide a universal strategy in this field.
{"title":"Surface modification of carbon dots by boron and phosphorus to construct flame-retardant epoxy resin with high mechanical and low dielectric properties","authors":"Lingzhi Wang , Hua Liu , Birong Zeng , Kaibin He , Yiting Xu , Conghui Yuan , Lizong Dai","doi":"10.1016/j.polymdegradstab.2025.111275","DOIUrl":"10.1016/j.polymdegradstab.2025.111275","url":null,"abstract":"<div><div>The effective combination of flame retardant element and carbon dots for the development of epoxy composites with high mechanical property and low dielectric constant in the field of flame retardant material is still a challenge. Herein, the boron and phosphorus dual-element doped carbon dots (BP&NCDs) was synthesized using a simple Kabachnik-Fields reaction, and then incorporated into epoxy resin in different amount to prepare a series of EP/BP&NCDs composites. The optical, thermal stability, mechanical, dielectric and flame-retardant properties were tested by many techniques such as UV–vis spectroscopy, FL, TEM, TG, UL-94 and LOI e.g. It showed that the EP/BP&NCDs composites had favorable transparency, hydrophobicity, mechanical and dielectric properties, while maintaining the photo-luminescent properties. It was worth noting that the EP/3 %-BP&NCDs composite with only 3 % BP&NCDs addition exhibited significant flame-retardant properties with a UL-94 V-0 rating and a limiting oxygen index (LOI) of 31.3 %. Meanwhile, it led to obvious reductions of 34.9 %, 26.6 %, and 15.6 % in peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP), respectively. Furthermore, compared with pure EP, the EP/3 %-BP&NCDs composites enhanced the bending strength and impact strength by 32.3 % and 30.3 %, but reduced the dielectric constant and dielectric loss by about 40.0 % and 50.0 %, respectively. When EP/BP&NCDs composites were burned, a continuous and dense carbon layer was formed due to the synergistic action of phosphorus and boron in CDs. Overall the carbon dots (CDs) after surface modification could be applied in epoxy resin system for the achievement of multiple functional EP composites with good flame retardancy, mechanical and dielectric property at low addition, which is helpful to provide a universal strategy in this field.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111275"},"PeriodicalIF":6.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyamide 6 (PA6) fabrics release toxic smoke during combustion, which contributes to environmental pollution and poses a serious threat to human health. In this study, a green polyelectrolyte flame-retardant coating (DT) was built using an ion-exchange reaction method and applied to the surface of PA6 fabric via a simple dipping-padding process. The limiting oxygen index (LOI) of the DT-treated PA6 fabric was increased from 19.1 % for the control PA6 fabric to 23.6 %. The damaged length was reduced from 16.0 cm for the control PA6 fabric to 3.5 cm, and the melt-dripping phenomenon was effectively eliminated. Compared to the control PA6 fabric (559 kW/m²and 22.1 MJ/m²), the heat release rate and total heat release of the DT-treated fabric were significantly reduced to 260.2 kW/m²and 14.7 MJ/m², respectively. Additionally, the DT coating enhanced the hygroscopicity of the PA6 fabric. Char residue analysis showed that the produced phosphoric acid and polyphosphoric acid effectively promoted the formation of a dense, and intumescent char layer, inhibiting the transfer of heat and oxygen. Furthermore, the release of non-flammable gases during combustion diluted the flammable gases, further enhancing the flame-retardant properties of the PA6 fabric. This environmentally friendly flame-retardant polyelectrolyte coating offers a sustainable approach for the development of eco-conscious flame-retardant fabrics.
{"title":"Development of a green polyelectrolyte coating to improve flame retardancy and hygroscopic properties of polyamide 6 fabrics","authors":"Pengyu Wang, Jian Liu, Hongfei Li, Xiaoyu Gu, Jun Sun, Sheng Zhang","doi":"10.1016/j.polymdegradstab.2025.111274","DOIUrl":"10.1016/j.polymdegradstab.2025.111274","url":null,"abstract":"<div><div>Polyamide 6 (PA6) fabrics release toxic smoke during combustion, which contributes to environmental pollution and poses a serious threat to human health. In this study, a green polyelectrolyte flame-retardant coating (DT) was built using an ion-exchange reaction method and applied to the surface of PA6 fabric via a simple dipping-padding process. The limiting oxygen index (LOI) of the DT-treated PA6 fabric was increased from 19.1 % for the control PA6 fabric to 23.6 %. The damaged length was reduced from 16.0 cm for the control PA6 fabric to 3.5 cm, and the melt-dripping phenomenon was effectively eliminated. Compared to the control PA6 fabric (559 kW/m²and 22.1 MJ/m²), the heat release rate and total heat release of the DT-treated fabric were significantly reduced to 260.2 kW/m²and 14.7 MJ/m², respectively. Additionally, the DT coating enhanced the hygroscopicity of the PA6 fabric. Char residue analysis showed that the produced phosphoric acid and polyphosphoric acid effectively promoted the formation of a dense, and intumescent char layer, inhibiting the transfer of heat and oxygen. Furthermore, the release of non-flammable gases during combustion diluted the flammable gases, further enhancing the flame-retardant properties of the PA6 fabric. This environmentally friendly flame-retardant polyelectrolyte coating offers a sustainable approach for the development of eco-conscious flame-retardant fabrics.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111274"},"PeriodicalIF":6.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-16DOI: 10.1016/j.polymdegradstab.2025.111271
Victor H. Pino-Ramos , E. Bucio , Lucy-Caterine Daza-Gómez , David Díaz
Polystyrene (PS) is a widely used single-use plastic and a major component of global waste. Its overaccumulation poses a critical environmental issue due to its non-biodegradable chemical structure, featuring phenyl moieties and long linear alkanes. Urgent recycling solutions are needed as the problem continues to worsen. In this work, the photodegradation of PS using (BiO)2CO3 nanoparticles under UV-light, converting it into useful products like phthalates which have potential applications as plasticizers. The effects of catalyst load and exposure time on the reaction yield are discussed in this research. The (BiO)2CO3 nanoparticle powders were obtained by atmospheric CO2 absorption, and they were characterized using XRD, SEM, HRTEM and SEM-EDS. The oxidized PS was analyzed using FTIR-ATR, TGA, and DSC, confirming successful oxidation at room temperature. The degradation products were identified by FTIR, and their structures verified by NMR 1H, 13C. This approach offers a promising recycling solution for PS waste.
{"title":"Photocatalytic degradation of polystyrene under mild conditions by nanostructured bismuth carbonate","authors":"Victor H. Pino-Ramos , E. Bucio , Lucy-Caterine Daza-Gómez , David Díaz","doi":"10.1016/j.polymdegradstab.2025.111271","DOIUrl":"10.1016/j.polymdegradstab.2025.111271","url":null,"abstract":"<div><div>Polystyrene (PS) is a widely used single-use plastic and a major component of global waste. Its overaccumulation poses a critical environmental issue due to its non-biodegradable chemical structure, featuring phenyl moieties and long linear alkanes. Urgent recycling solutions are needed as the problem continues to worsen. In this work, the photodegradation of PS using (BiO)<sub>2</sub>CO<sub>3</sub> nanoparticles under UV-light, converting it into useful products like phthalates which have potential applications as plasticizers. The effects of catalyst load and exposure time on the reaction yield are discussed in this research. The (BiO)<sub>2</sub>CO<sub>3</sub> nanoparticle powders were obtained by atmospheric CO<sub>2</sub> absorption, and they were characterized using XRD, SEM, HRTEM and SEM-EDS. The oxidized PS was analyzed using FTIR-ATR, TGA, and DSC, confirming successful oxidation at room temperature. The degradation products were identified by FTIR, and their structures verified by NMR <sup>1</sup>H, <sup>13</sup>C. This approach offers a promising recycling solution for PS waste.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111271"},"PeriodicalIF":6.3,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1016/j.polymdegradstab.2025.111270
Tjaša Rijavec , Sonia Bujok , Sergii Antropov , G. Asher Newsome , Josep Grau-Bové , Irena Kralj Cigić , Krzysztof Kruczała , Łukasz Bratasz , Matija Strlič
The predominance of diffusion-evaporation of plasticizers in heritage collections is investigated and an analytical method of studying surface exudates based on dry swabbing is introduced for an in-situ museum survey. Most plasticized heritage PVC objects exhibit no visible surface exudates, indicating plasticizer loss is governed by the diffusion-evaporation process and not phase-separation. A new approach to analyzing the diffusion-evaporation process based on experimental data is presented to model plasticizer loss at room conditions. Experiments conducted with historical PVC objects exposed to accelerated degradation for up to 8 weeks at moderate temperatures enable the monitoring of plasticizer loss. Evaluation of the mass loss and the chromatographically determined plasticizer content allows us to determine the temperature dependence of the diffusion coefficient and the surface emission coefficient. Three representative groups of heritage PVC are identified and the activation energies for the coupled diffusion-evaporation processes are used to determine the rate-limiting step and introduce a general model for predicting plasticizer loss from the time of storage, temperature, and thickness of an object. The model can be used as part of risk assessment in heritage PVC collections.
{"title":"Heritage PVC objects: Understanding the diffusion-evaporation of plasticizers","authors":"Tjaša Rijavec , Sonia Bujok , Sergii Antropov , G. Asher Newsome , Josep Grau-Bové , Irena Kralj Cigić , Krzysztof Kruczała , Łukasz Bratasz , Matija Strlič","doi":"10.1016/j.polymdegradstab.2025.111270","DOIUrl":"10.1016/j.polymdegradstab.2025.111270","url":null,"abstract":"<div><div>The predominance of diffusion-evaporation of plasticizers in heritage collections is investigated and an analytical method of studying surface exudates based on dry swabbing is introduced for an <em>in-situ</em> museum survey. Most plasticized heritage PVC objects exhibit no visible surface exudates, indicating plasticizer loss is governed by the diffusion-evaporation process and not phase-separation. A new approach to analyzing the diffusion-evaporation process based on experimental data is presented to model plasticizer loss at room conditions. Experiments conducted with historical PVC objects exposed to accelerated degradation for up to 8 weeks at moderate temperatures enable the monitoring of plasticizer loss. Evaluation of the mass loss and the chromatographically determined plasticizer content allows us to determine the temperature dependence of the diffusion coefficient and the surface emission coefficient. Three representative groups of heritage PVC are identified and the activation energies for the coupled diffusion-evaporation processes are used to determine the rate-limiting step and introduce a general model for predicting plasticizer loss from the time of storage, temperature, and thickness of an object. The model can be used as part of risk assessment in heritage PVC collections.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111270"},"PeriodicalIF":6.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The degradation profiles of poly(butylene succinate) (PBS) with filler were quantitatively evaluated with respect to the degradation rate and the effect of filler content. The types of fillers examined were activated carbon (AC), mesoporous silica, and cellulose nanofiber. Compost degradation and temperature-elevated hydrolysis were performed, and the rate of molecular weight reduction was found to be independent of filler type and content. The ISO 14,855–1 protocol showed no effect of microbial degradation on the molecular weight change profile but did reveal degradation by hydrolysis. The low filler content did not affect the crystallinity or polydispersity index, which suggests that the degradation proceeded uniformly in the crystalline and amorphous phases. However, the crystallinity was lower when the content was high, and the weight decreased at a higher rate. These results suggest that crystallization was inhibited by AC during sample molding, thus promoted the elution of low-molecular-weight components, which were stuck in crystalline regime, from amorphous regime. No AC discharge was observed during temperature-elevated hydrolysis, which was quantitatively confirmed by carbon balance analysis. This finding suggested that the hydrolysis rate of PBS around the AC was very small. The kinetic analysis of the molecular weight change profile of PBS was conducted, and the activation energy of degradation was determined to be 73 kJ/mol. The parameters determined in this study enable the prediction of the time change in the molecular weight of PBS resulting from hydrolysis.
{"title":"Degradation behavior of polybutylene succinate with fillers","authors":"Yosuke Muranaka, Takanari Koike, Tatsuya Osuga, Taisuke Maki","doi":"10.1016/j.polymdegradstab.2025.111266","DOIUrl":"10.1016/j.polymdegradstab.2025.111266","url":null,"abstract":"<div><div>The degradation profiles of poly(butylene succinate) (<strong>PBS</strong>) with filler were quantitatively evaluated with respect to the degradation rate and the effect of filler content. The types of fillers examined were activated carbon (<strong>AC</strong>), mesoporous silica, and cellulose nanofiber. Compost degradation and temperature-elevated hydrolysis were performed, and the rate of molecular weight reduction was found to be independent of filler type and content. The ISO 14,855–1 protocol showed no effect of microbial degradation on the molecular weight change profile but did reveal degradation by hydrolysis. The low filler content did not affect the crystallinity or polydispersity index, which suggests that the degradation proceeded uniformly in the crystalline and amorphous phases. However, the crystallinity was lower when the content was high, and the weight decreased at a higher rate. These results suggest that crystallization was inhibited by AC during sample molding, thus promoted the elution of low-molecular-weight components, which were stuck in crystalline regime, from amorphous regime. No AC discharge was observed during temperature-elevated hydrolysis, which was quantitatively confirmed by carbon balance analysis. This finding suggested that the hydrolysis rate of PBS around the AC was very small. The kinetic analysis of the molecular weight change profile of PBS was conducted, and the activation energy of degradation was determined to be 73 kJ/mol. The parameters determined in this study enable the prediction of the time change in the molecular weight of PBS resulting from hydrolysis.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111266"},"PeriodicalIF":6.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1016/j.polymdegradstab.2025.111267
Hanin Alkhamis , Shivam Saretia , Susanne Schwanz , Rainhard Machatschek , Axel T. Neffe , Katarzyna Polak-Kraśna
Appropriate degradation behavior of medical implants is essential, as early degradation of implanted biomaterials can lead to premature loss of mechanical integrity, causing complications such as inflammation and inadequate support during the critical healing period. Therefore, understanding the degradation of newly developed materials for in vivo applications is crucial. Here, we investigated the degradation behavior of blends from Poly[(L-lactide)-co-(ε-caprolactone)] and Poly(D-lactide) (PLLAcoCL/PDLA) in which stereocomplex crystals of the isotactic lactide sequences impart hyperelastic behavior. The PLLAcoCL/PDLA blends were studied through in vitro bulk degradation studies (in printed films and electrospun meshes) and in thin-films using the Langmuir technique. Chemical, thermal, and mechanical properties were assessed at different time-points, highlighting the effects of blends composition and stereocomplexation. The PLLAcoCL/PDLA polymer blend shows promising potential as a covering for expandable cardiovascular implants, offering high ultimate strains (up to >700 %), elasticity, stability, and minimal mass loss during the crucial early healing period (4 weeks). Mechanical data suggest that specific blend ratios, particularly the 95:5 ratio in electrospun meshes, maintained mechanical integrity longer than others (E = 5.7 MPa at week 9), which was reflected in the mass loss of meshes (remaining mass = 67 wt% at week 20). Lower PDLA content accelerated early degradation while enhancing oxidative resistance, whereas higher PDLA content slowed degradation but increased crystallinity. These findings emphasize how blend composition influences degradation rates, mechanical behavior, and stability. Findings highlight the role of composition in tailoring implant degradation and support predictive modeling for cardiovascular applications.
{"title":"Understanding the degradation and mechanical performance of hyperelastic polylactide copolymers through bulk and ultrathin film analysis correlation","authors":"Hanin Alkhamis , Shivam Saretia , Susanne Schwanz , Rainhard Machatschek , Axel T. Neffe , Katarzyna Polak-Kraśna","doi":"10.1016/j.polymdegradstab.2025.111267","DOIUrl":"10.1016/j.polymdegradstab.2025.111267","url":null,"abstract":"<div><div>Appropriate degradation behavior of medical implants is essential, as early degradation of implanted biomaterials can lead to premature loss of mechanical integrity, causing complications such as inflammation and inadequate support during the critical healing period. Therefore, understanding the degradation of newly developed materials for in vivo applications is crucial. Here, we investigated the degradation behavior of blends from Poly[(L-lactide)-co-(ε-caprolactone)] and Poly(D-lactide) (PLLAcoCL/PDLA) in which stereocomplex crystals of the isotactic lactide sequences impart hyperelastic behavior. The PLLAcoCL/PDLA blends were studied through in vitro bulk degradation studies (in printed films and electrospun meshes) and in thin-films using the Langmuir technique. Chemical, thermal, and mechanical properties were assessed at different time-points, highlighting the effects of blends composition and stereocomplexation. The PLLAcoCL/PDLA polymer blend shows promising potential as a covering for expandable cardiovascular implants, offering high ultimate strains (up to >700 %), elasticity, stability, and minimal mass loss during the crucial early healing period (4 weeks). Mechanical data suggest that specific blend ratios, particularly the 95:5 ratio in electrospun meshes, maintained mechanical integrity longer than others (<em>E</em> = 5.7 MPa at week 9), which was reflected in the mass loss of meshes (remaining mass = 67 wt% at week 20). Lower PDLA content accelerated early degradation while enhancing oxidative resistance, whereas higher PDLA content slowed degradation but increased crystallinity. These findings emphasize how blend composition influences degradation rates, mechanical behavior, and stability. Findings highlight the role of composition in tailoring implant degradation and support predictive modeling for cardiovascular applications.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111267"},"PeriodicalIF":6.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, microwave (MW)-assisted oxidative degradation of poly(vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene) (P(VDF-TFE-HFP)) was applied to synthesize carboxy-terminated liquid fluororubber, referred to as LTCFs-246. The resulting product has a carboxyl content of 3.01%, a number-average molecular weight (Mn) of 2100 g/mol, and a polydispersity index (PDI) of 1.61. The product's structure was characterized and analyzed in detail using techniques such as 19F NMR, UV–Vis, and FTIR spectroscopy. Results indicate that the selective dehydrofluorination reaction (KHF reaction) primarily occurs on four sequence structures: HFP-VDF-HFP, HFP-VDF-TFE, TFE-VDF-HFP, and TFE-VDF-TFE, with similar degrees of reactivity across these structures. Two types of C=C bonds were formed in the LTCFs-246 backbone, primarily through Hofmann elimination and, to a lesser extent, Zaitsev elimination. The oxidative reaction (KC-C reaction) was temperature-dependent. At lower temperatures, H2O2 decomposed slowly, limiting the KC-C reaction; as the temperature increased, H2O2 rapidly decomposed, actively engaging in the KC-C reaction and extensively consuming C=C bonds. Once H2O2 was fully consumed, the KC-C reaction ceased, while the KHF reaction continued uninterrupted. In conclusion, this study provides strong evidence to advance the understanding of the oxidative degradation mechanism of MW-assisted P(VDF-TFE-HFP).
{"title":"Microwave-Assisted oxidative degradation of poly(vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene): Preparation, characterization, and reaction mechanism","authors":"Ranran Qi, Ziwen Gan, Qi Wang, Xiaojie Zhang, Mingyi Liao","doi":"10.1016/j.polymdegradstab.2025.111269","DOIUrl":"10.1016/j.polymdegradstab.2025.111269","url":null,"abstract":"<div><div>In this study, microwave (MW)-assisted oxidative degradation of poly(vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene) (P(VDF-TFE-HFP)) was applied to synthesize carboxy-terminated liquid fluororubber, referred to as LTCFs-246. The resulting product has a carboxyl content of 3.01%, a number-average molecular weight (Mn) of 2100 g/mol, and a polydispersity index (PDI) of 1.61. The product's structure was characterized and analyzed in detail using techniques such as <sup>19</sup>F NMR, UV–Vis, and FTIR spectroscopy. Results indicate that the selective dehydrofluorination reaction (K<sub>HF</sub> reaction) primarily occurs on four sequence structures: HFP-VDF-HFP, HFP-VDF-TFE, TFE-VDF-HFP, and TFE-VDF-TFE, with similar degrees of reactivity across these structures. Two types of C=C bonds were formed in the LTCFs-246 backbone, primarily through Hofmann elimination and, to a lesser extent, Zaitsev elimination. The oxidative reaction (K<sub>C-C</sub> reaction) was temperature-dependent. At lower temperatures, H<sub>2</sub>O<sub>2</sub> decomposed slowly, limiting the K<sub>C-C</sub> reaction; as the temperature increased, H<sub>2</sub>O<sub>2</sub> rapidly decomposed, actively engaging in the K<sub>C-C</sub> reaction and extensively consuming C=C bonds. Once H<sub>2</sub>O<sub>2</sub> was fully consumed, the K<sub>C-C</sub> reaction ceased, while the K<sub>HF</sub> reaction continued uninterrupted. In conclusion, this study provides strong evidence to advance the understanding of the oxidative degradation mechanism of MW-assisted P(VDF-TFE-HFP).</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111269"},"PeriodicalIF":6.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, novel block copolymers consisting of poly(ethylene succinate) (PES) and poly(amino acid)s were synthesized, and their thermal and mechanical properties and biodegradability characteristics were investigated. Various types of poly(amino acid) units were successfully introduced using N-phenyloxycarbonyl amino acids (NPCs). The reactions between the terminally aminated PES and the NPCs were conducted by heating in N,N-dimethylacetamide at 65 °C. Structural analyses of the obtained polymers confirmed that the reaction with the NPCs proceeded from both ends of the terminally aminated PES. The results of material property measurements demonstrated that the melting point of the block copolymer containing poly(alanine) units increased beyond 200 °C while that of the original PES was ∼100 °C. Additionally, its strain at break increased ∼80-fold compared to that of PES with a similar molecular weight. The results of biodegradability tests using a soil suspension as an inoculum indicated that some of the block copolymers underwent biodegradation, and a correlation was observed between the biodegradability and the type and feed amount of NPC. Therefore, it was proposed that the degree, rate, and onset time of biodegradation could be controlled by altering the type and amount of incorporated poly(amino acid) units. This research may contribute to the optimal and facile synthesis of polyester-b-poly(amino acid) copolymers and to the expansion of the range of available biodegradable materials.
{"title":"Synthesis and characterization of block copolymers consisting of poly(ethylene succinate) and poly(amino acid)s","authors":"Sumito Kumagai , Motosuke Imada , Senri Hayashi , Atsushi Katsuragi , Kaoko Sato , Hideki Abe , Noriyuki Asakura , Yasumasa Takenaka","doi":"10.1016/j.polymdegradstab.2025.111265","DOIUrl":"10.1016/j.polymdegradstab.2025.111265","url":null,"abstract":"<div><div>In this study, novel block copolymers consisting of poly(ethylene succinate) (PES) and poly(amino acid)s were synthesized, and their thermal and mechanical properties and biodegradability characteristics were investigated. Various types of poly(amino acid) units were successfully introduced using <em>N</em>-phenyloxycarbonyl amino acids (NPCs). The reactions between the terminally aminated PES and the NPCs were conducted by heating in <em>N,N</em>-dimethylacetamide at 65 °C. Structural analyses of the obtained polymers confirmed that the reaction with the NPCs proceeded from both ends of the terminally aminated PES. The results of material property measurements demonstrated that the melting point of the block copolymer containing poly(alanine) units increased beyond 200 °C while that of the original PES was ∼100 °C. Additionally, its strain at break increased ∼80-fold compared to that of PES with a similar molecular weight. The results of biodegradability tests using a soil suspension as an inoculum indicated that some of the block copolymers underwent biodegradation, and a correlation was observed between the biodegradability and the type and feed amount of NPC. Therefore, it was proposed that the degree, rate, and onset time of biodegradation could be controlled by altering the type and amount of incorporated poly(amino acid) units. This research may contribute to the optimal and facile synthesis of polyester-<em>b</em>-poly(amino acid) copolymers and to the expansion of the range of available biodegradable materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111265"},"PeriodicalIF":6.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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