Polymer Degradation and Stability最新文献_第8页

Ti3C2Tx/layered double hydroxide hybrid system decorated with iron-loaded polydopamine as a hydrophobic flame retardant for reducing the fire hazard of ethylene-vinyl acetate

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-03-01 DOI: 10.1016/j.polymdegradstab.2025.111297

Weidou Li , Yuwei Zhou , Zihan Zeng , Yile Ding , Xinyang Wu , Lei Wang , Wufei Tang , Qi Zhu , Jiayao Zhou , Sheng Xu

In recent years, MXene (Ti₃C₂Tx) has been extensively studied and used in polymer composites. However, MXene easily agglomerates in polymeric materials and has significant limitations in compatibility with hydrophobic polymers, resulting in the impairment of their mechanical properties and greatly hindering the improvement of their flame retardant properties. In this study, in order to improve the interfacial compatibility of the flame retardant with EVA, we prepared a Ti₃C₂Tx/MgAl LDH/PDA-Fe composite flame retardant by loading iron-loaded polydopamine (PDA-Fe) on the surface of Ti₃C₂Tx/layered double hydroxide (MgAl LDH) using polydopamine as an adhesive. Due to the strong adhesion of PDA, the interfacial compatibility between the flame retardant and EVA was greatly improved. And the hydrophobicity of Ti₃C₂Tx/MgAl LDH/PDA-Fe was greatly enhanced with a water contact angle value of 88.6°, which further enhanced the flame retardant properties of the EVA composites. The peak heat release rate of the EVA composites with the addition of 5 wt% Ti₃C₂Tx/MgAl LDH/PDA-Fe was 659.7 kW·m⁻², which represented a 29.1 % decrease compared to that of Neat EVA. In addition, the MgAl LDH inhibited the accumulation of Ti₃C₂Tx in EVA, and their synergistic effect improved the fire safety of EVA composites. Thus, this study provides a new paradigm for the preparation of hydrophobic flame retardants capable of improving interfacial compatibility with EVA, which has a promising application.

{"title":"Ti3C2Tx/layered double hydroxide hybrid system decorated with iron-loaded polydopamine as a hydrophobic flame retardant for reducing the fire hazard of ethylene-vinyl acetate","authors":"Weidou Li , Yuwei Zhou , Zihan Zeng , Yile Ding , Xinyang Wu , Lei Wang , Wufei Tang , Qi Zhu , Jiayao Zhou , Sheng Xu","doi":"10.1016/j.polymdegradstab.2025.111297","DOIUrl":"10.1016/j.polymdegradstab.2025.111297","url":null,"abstract":"<div><div>In recent years, MXene (Ti<sub>3</sub>C<sub>2</sub>Tx) has been extensively studied and used in polymer composites. However, MXene easily agglomerates in polymeric materials and has significant limitations in compatibility with hydrophobic polymers, resulting in the impairment of their mechanical properties and greatly hindering the improvement of their flame retardant properties. In this study, in order to improve the interfacial compatibility of the flame retardant with EVA, we prepared a Ti<sub>3</sub>C<sub>2</sub>Tx/MgAl LDH/PDA-Fe composite flame retardant by loading iron-loaded polydopamine (PDA-Fe) on the surface of Ti<sub>3</sub>C<sub>2</sub>Tx/layered double hydroxide (MgAl LDH) using polydopamine as an adhesive. Due to the strong adhesion of PDA, the interfacial compatibility between the flame retardant and EVA was greatly improved. And the hydrophobicity of Ti<sub>3</sub>C<sub>2</sub>Tx/MgAl LDH/PDA-Fe was greatly enhanced with a water contact angle value of 88.6°, which further enhanced the flame retardant properties of the EVA composites. The peak heat release rate of the EVA composites with the addition of 5 wt% Ti<sub>3</sub>C<sub>2</sub>Tx/MgAl LDH/PDA-Fe was 659.7 kW·m<sup>−</sup><sup>2</sup>, which represented a 29.1 % decrease compared to that of Neat EVA. In addition, the MgAl LDH inhibited the accumulation of Ti<sub>3</sub>C<sub>2</sub>Tx in EVA, and their synergistic effect improved the fire safety of EVA composites. Thus, this study provides a new paradigm for the preparation of hydrophobic flame retardants capable of improving interfacial compatibility with EVA, which has a promising application.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"236 ","pages":"Article 111297"},"PeriodicalIF":6.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552906","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}

引用次数: 0

Enhancing the liquid oxygen compatibility of epoxy resin by introducing a novel phosphorus / sulfur-containing flame retardant

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-27 DOI: 10.1016/j.polymdegradstab.2025.111296

Rui Yin , Yuhang Liu , Yi Luo , Jia Yan , Jialiang Li , Duo Chen , Tao Sun , Shichao Li , Zhanjun Wu

The compatibility between epoxy resin with liquid oxygen (LOX) plays the critical role in the application of resin-based composite to LOX tanks of launch vehicles. A novel phosphorus/sulfur-containing flame retardant (DPAMT) was synthesized via a facile one-pot method with DOPO, p-hydroxybenzaldehyde and 2-Amino-5-mercapto-1,3,4-thiadiazole and used to enhance the LOX compatibility of epoxy resin. The chemical structure of DPAMT was confirmed by FTIR spectra, ¹H NMR and ³¹P NMR spectra. The impact reaction sensitivity (IRS) index of modified epoxy resin decreased with increasing DPAMT content and reached zero (means being compatible with LOX) when the DPAMT content was up to 6 wt.%. TGA, LOI values, UL-94 test, Cone calorimeter test (CCT), XPS of residues after LOX impact and pyrolysis behavior of DPAMT were investigated to explore the mechanism of DPAMT affecting the LOX compatibility of epoxy resin. The results showed that DPAMT endowed epoxy resin with enhanced thermal stability and excellent flame retardancy. When the modified epoxy resin suffered impacts, the S·, PO· and PO₂· radicals as well as SO₂ exserting quenching effect by reacting with the active H·, OH· and O· radicals were released. Meanwhile, the P-containing acids and S-containing acids generated promoted the dehydration and carbonization of the epoxy resin to form protective charring layer. It was considered that the synthesized DPAMT was an effective addictive of epoxy resin to enhance the compatibility with LOX.

{"title":"Enhancing the liquid oxygen compatibility of epoxy resin by introducing a novel phosphorus / sulfur-containing flame retardant","authors":"Rui Yin , Yuhang Liu , Yi Luo , Jia Yan , Jialiang Li , Duo Chen , Tao Sun , Shichao Li , Zhanjun Wu","doi":"10.1016/j.polymdegradstab.2025.111296","DOIUrl":"10.1016/j.polymdegradstab.2025.111296","url":null,"abstract":"<div><div>The compatibility between epoxy resin with liquid oxygen (LOX) plays the critical role in the application of resin-based composite to LOX tanks of launch vehicles. A novel phosphorus/sulfur-containing flame retardant (DPAMT) was synthesized via a facile one-pot method with DOPO, p-hydroxybenzaldehyde and 2-Amino-5-mercapto-1,3,4-thiadiazole and used to enhance the LOX compatibility of epoxy resin. The chemical structure of DPAMT was confirmed by FTIR spectra, <sup>1</sup>H NMR and <sup>31</sup>P NMR spectra. The impact reaction sensitivity (IRS) index of modified epoxy resin decreased with increasing DPAMT content and reached zero (means being compatible with LOX) when the DPAMT content was up to 6 wt.%. TGA, LOI values, UL-94 test, Cone calorimeter test (CCT), XPS of residues after LOX impact and pyrolysis behavior of DPAMT were investigated to explore the mechanism of DPAMT affecting the LOX compatibility of epoxy resin. The results showed that DPAMT endowed epoxy resin with enhanced thermal stability and excellent flame retardancy. When the modified epoxy resin suffered impacts, the S·, PO· and PO<sub>2</sub>· radicals as well as SO<sub>2</sub> exserting quenching effect by reacting with the active H·, OH· and O· radicals were released. Meanwhile, the P-containing acids and S-containing acids generated promoted the dehydration and carbonization of the epoxy resin to form protective charring layer. It was considered that the synthesized DPAMT was an effective addictive of epoxy resin to enhance the compatibility with LOX.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"236 ","pages":"Article 111296"},"PeriodicalIF":6.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580431","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}

引用次数: 0

Properties and mechanism of high-performance flame retardant thermoplastic vulcanizate with alkenyl-crosslinking molecule

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-27 DOI: 10.1016/j.polymdegradstab.2025.111278

Siqi Chen , Lijun Qian , Junxiao Li , Jingyu Wang

The structural morphology of flame retardants within a polymer matrix is a key factor affecting their flame retardancy, dispersibility, compatibility, and mechanical properties. In this study, an alkenyl-crosslinking flame retardant molecule (AFR-GMA) was designed and synthesized, demonstrating significantly enhanced flame retardant performance compared to piperazine pyrophosphate (PAPP), alongside improvements in mechanical properties. Incorporating 22 % AFR-GMA/MPP into thermoplastic vulcanizate (TPV) passed 1.6 mm UL 94 V-0 rating, while the LOI rose from 18.2 % to 29.4 %, higher than 26.2 % of 22 % (PAPP/MPP)/TPV. During combustion, AFR-GMA facilitated the retention of more phosphorus and carbon within the residual char, forming a denser char structure and exhibiting superior condensed phase flame retardant effects. Cone calorimetry test revealed that the PHRR and PSPR of the AFR-GMA/MPP/TPV composite decreased by 74.8 % and 50 %, respectively, compared to pure TPV, while the residual weight increased from 0.14 % to 28.5 %. Regarding mechanical properties, the addition of AFR-GMA maintaining excellent tensile strength and elongation at break of TPV composites. In summary, the introduction of alkenyl-crosslinking flame retardant molecule retained great flame retardancy and mechanical properties of the TPV composites, offering a promising approach for the design and application of alkenyl-crosslinking flame retardants in commercial settings.

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引用次数: 0

Biodegradation of pre-treated low-density polyethylene (LDPE) by Yarrowia lipolytica determined by oxidation and molecular weight reduction

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-27 DOI: 10.1016/j.polymdegradstab.2025.111292

G. Buron-Moles , V. Vandenbossche , N. Gorret , L. Santonja-Blasco , T. González-Aranda , X. Cameleyre , S. Guillouet

Millions of metric tonnes of plastic waste are generated every year, with a minimal portion being recycled. Therefore, there is an urgent need to find effective and sustainable methods for plastic degradation, especially polyethylene, the most manufactured polymer globally. Here, we emulate the strategies documented for beetles, characterized by a combination of physical, chemical, and microbiological treatments, to biodegrade low-density polyethylene (LDPE). Importantly, we characterize LDPE degradation through multiple techniques, including weight loss analysis, FTIR, GPC, GC–MS, and SEM, which allowed us to identify the optimal combination of treatments to enhance LDPE biodegradation. Contrary to some expectations, we find that ultrasonication does not contribute to LDPE degradation but may instead protect against its fragmentation. However, we successfully introduce carbonyl groups into the polymer backbone, by simply exposing LDPE to environmentally friendly anionic surfactant. This pretreatment effectively cleaves LDPE by approximately 9%, breaking it into shorter carbon chains that are more accessible to microbes for subsequent biodegradation. The yeast Yarrowia lipolytica, isolated from fuel tanks and able to grow in n-paraffines, not only outperforms other microbes in assays of short carbon chain degradation, but also attaches to the LDPE surface, where it survives and grows using LDPE as sole carbon source. Our findings, therefore, pave the way for further developing a potential solution to plastic waste, calling for interdisciplinary research and innovative solutions in tackling global environmental challenges.

{"title":"Biodegradation of pre-treated low-density polyethylene (LDPE) by Yarrowia lipolytica determined by oxidation and molecular weight reduction","authors":"G. Buron-Moles , V. Vandenbossche , N. Gorret , L. Santonja-Blasco , T. González-Aranda , X. Cameleyre , S. Guillouet","doi":"10.1016/j.polymdegradstab.2025.111292","DOIUrl":"10.1016/j.polymdegradstab.2025.111292","url":null,"abstract":"<div><div>Millions of metric tonnes of plastic waste are generated every year, with a minimal portion being recycled. Therefore, there is an urgent need to find effective and sustainable methods for plastic degradation, especially polyethylene, the most manufactured polymer globally. Here, we emulate the strategies documented for beetles, characterized by a combination of physical, chemical, and microbiological treatments, to biodegrade low-density polyethylene (LDPE). Importantly, we characterize LDPE degradation through multiple techniques, including weight loss analysis, FTIR, GPC, GC–MS, and SEM, which allowed us to identify the optimal combination of treatments to enhance LDPE biodegradation. Contrary to some expectations, we find that ultrasonication does not contribute to LDPE degradation but may instead protect against its fragmentation. However, we successfully introduce carbonyl groups into the polymer backbone, by simply exposing LDPE to environmentally friendly anionic surfactant. This pretreatment effectively cleaves LDPE by approximately 9%, breaking it into shorter carbon chains that are more accessible to microbes for subsequent biodegradation. The yeast <em>Yarrowia lipolytica</em>, isolated from fuel tanks and able to grow in <em>n</em>-paraffines, not only outperforms other microbes in assays of short carbon chain degradation, but also attaches to the LDPE surface, where it survives and grows using LDPE as sole carbon source. Our findings, therefore, pave the way for further developing a potential solution to plastic waste, calling for interdisciplinary research and innovative solutions in tackling global environmental challenges.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"236 ","pages":"Article 111292"},"PeriodicalIF":6.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594245","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}

引用次数: 0

Self-assembly of triazolyl-based cyclomatrix polyphosphazene and melamine cyanurate for flame-retardant, smoke-suppressing, and mechanically robust epoxy resin

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-27 DOI: 10.1016/j.polymdegradstab.2025.111268

Xiao-Jie Li , Cai Liu , Cong-Yun Zhang , Zhu-Bao Shao , Bin Zhao

Epoxy resin (EP) is widely utilized in construction, rail transit, and structural engineering as coatings, adhesives, and resin matrices for fiber-reinforced composites, owing to its excellent processability, adhesion, thermal stability, and mechanical strength. However, its inherent high flammability significantly restricts its application in scenarios requiring stringent fire safety standards. Addressing this challenge, we developed a novel triazolyl-based cyclomatrix polyphosphazene (HTDA) that self-assembles with melamine cyanurate (MCA) through hydrogen bonding, forming a hybrid flame retardant (HTDA@MCA) with a distinctive lamellar structure. The impact of HTDA and HTDA@MCA on EP's thermal stability, fire resistance, and mechanical performance was systematically evaluated. Compared to HTDA alone, the HTDA@MCA hybrid demonstrated superior performance, significantly enhancing EP's elastic modulus, crosslink density, and glass transition temperature. At HTDA@MCA loadings of 7.5 % and 10 %, EP achieved a UL-94 V-0 rating and limiting oxygen index (LOI) values of 28.6 % and 29.4 %, respectively. Cone calorimeter and smoke density tests further revealed a 68 % reduction in peak heat release rate and a 54.8 % decrease in smoke production. The excellent dispersion and unique lamellar structure of HTDA@MCA contributed to significant improvements in EP's mechanical properties. This study proposes an innovative strategy for simultaneously improving the fire safety, thermal stability, and mechanical strength of EP, providing valuable guidance for the development of high-performance polymeric materials.

{"title":"Self-assembly of triazolyl-based cyclomatrix polyphosphazene and melamine cyanurate for flame-retardant, smoke-suppressing, and mechanically robust epoxy resin","authors":"Xiao-Jie Li , Cai Liu , Cong-Yun Zhang , Zhu-Bao Shao , Bin Zhao","doi":"10.1016/j.polymdegradstab.2025.111268","DOIUrl":"10.1016/j.polymdegradstab.2025.111268","url":null,"abstract":"<div><div>Epoxy resin (EP) is widely utilized in construction, rail transit, and structural engineering as coatings, adhesives, and resin matrices for fiber-reinforced composites, owing to its excellent processability, adhesion, thermal stability, and mechanical strength. However, its inherent high flammability significantly restricts its application in scenarios requiring stringent fire safety standards. Addressing this challenge, we developed a novel triazolyl-based cyclomatrix polyphosphazene (HTDA) that self-assembles with melamine cyanurate (MCA) through hydrogen bonding, forming a hybrid flame retardant (HTDA@MCA) with a distinctive lamellar structure. The impact of HTDA and HTDA@MCA on EP's thermal stability, fire resistance, and mechanical performance was systematically evaluated. Compared to HTDA alone, the HTDA@MCA hybrid demonstrated superior performance, significantly enhancing EP's elastic modulus, crosslink density, and glass transition temperature. At HTDA@MCA loadings of 7.5 % and 10 %, EP achieved a UL-94 V-0 rating and limiting oxygen index (LOI) values of 28.6 % and 29.4 %, respectively. Cone calorimeter and smoke density tests further revealed a 68 % reduction in peak heat release rate and a 54.8 % decrease in smoke production. The excellent dispersion and unique lamellar structure of HTDA@MCA contributed to significant improvements in EP's mechanical properties. This study proposes an innovative strategy for simultaneously improving the fire safety, thermal stability, and mechanical strength of EP, providing valuable guidance for the development of high-performance polymeric materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"235 ","pages":"Article 111268"},"PeriodicalIF":6.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509082","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}

引用次数: 0

Creation of sequence-regulating polyhydroxyalkanoate (PHA) synthases with improved thermostability using a full consensus design for the biosynthesis of 2-hydroxyalkanoate-based PHA block copolymers

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-27 DOI: 10.1016/j.polymdegradstab.2025.111295

Shoko Furukawa , Naoya Nakagawa , Shin-ichi Hachisuka , Shogo Nakano , Hiroya Tomita , Hiroshi Kikukawa , Ken'ichiro Matsumoto

Engineered polyhydroxyalkanoate (PHA) synthase PhaC_AR is a chimeric enzyme composed of PhaCs from Aeromonas caviae and Ralstonia eutropha (formally Cupriavidus necator). The enzyme has a broad substrate scope and unique sequence-regulating capacity: spontaneous synthesis of various block copolymers. This study aimed to acquire new sequence-regulating PHA synthases with a broader substrate scope and improved thermal stability. To meet this goal, artificial PHA synthases were designed using the full consensus design (FCD) algorithm. Based on amino acid sequences of PHA synthases with homology to PhaC from R. eutropha in the database, four artificial PHA synthases, FcPhaC1, FcPhaC2, FcPhaC4, and FcPhaC5, were created and expressed in Escherichia coli together with the monomer-supplying enzyme. Cells were cultivated with the supplementation of monomer precursors in the medium. As a result, these four FcPhaCs synthesized poly(3-hydroxybutyrate) [P(3HB)], although polymer production was slightly lower than that obtained using PhaC_AR, indicating that the algorithm successfully designed functional enzymes. FcPhaC1, FcPhaC4, and FcPhaC5 remained active after isothermal treatment at 60 °C for 30 min, whereas PhaC_AR and FcPhaC2 were inactivated. Therefore, the artificial PhaCs possessed improved thermal stability compared to PhaC_AR. The four FcPhaCs synthesized poly(glycolate-co-3HB) [P(GL-co-3HB)] with a block sequence as well as PhaC_AR. FcPhaC4 exhibited the highest GL fraction in P(GL-co-3HB) among the PhaCs tested. FcPhaC4 synthesized P(3HB)-b-P(2-hydroxybutyrate) and P(3HB)-b-polylactate, indicating its broad substrate scope. These results demonstrated the effectiveness of the FCD approach for creating sequence-regulating PHA synthases applicable to a wide range of polymer syntheses.

{"title":"Creation of sequence-regulating polyhydroxyalkanoate (PHA) synthases with improved thermostability using a full consensus design for the biosynthesis of 2-hydroxyalkanoate-based PHA block copolymers","authors":"Shoko Furukawa , Naoya Nakagawa , Shin-ichi Hachisuka , Shogo Nakano , Hiroya Tomita , Hiroshi Kikukawa , Ken'ichiro Matsumoto","doi":"10.1016/j.polymdegradstab.2025.111295","DOIUrl":"10.1016/j.polymdegradstab.2025.111295","url":null,"abstract":"<div><div>Engineered polyhydroxyalkanoate (PHA) synthase PhaC<sub>AR</sub> is a chimeric enzyme composed of PhaCs from <em>Aeromonas caviae</em> and <em>Ralstonia eutropha</em> (formally <em>Cupriavidus necator</em>). The enzyme has a broad substrate scope and unique sequence-regulating capacity: spontaneous synthesis of various block copolymers. This study aimed to acquire new sequence-regulating PHA synthases with a broader substrate scope and improved thermal stability. To meet this goal, artificial PHA synthases were designed using the full consensus design (FCD) algorithm. Based on amino acid sequences of PHA synthases with homology to PhaC from <em>R. eutropha</em> in the database, four artificial PHA synthases, FcPhaC1, FcPhaC2, FcPhaC4, and FcPhaC5, were created and expressed in <em>Escherichia coli</em> together with the monomer-supplying enzyme. Cells were cultivated with the supplementation of monomer precursors in the medium. As a result, these four FcPhaCs synthesized poly(3-hydroxybutyrate) [P(3HB)], although polymer production was slightly lower than that obtained using PhaC<sub>AR</sub>, indicating that the algorithm successfully designed functional enzymes. FcPhaC1, FcPhaC4, and FcPhaC5 remained active after isothermal treatment at 60 °C for 30 min, whereas PhaC<sub>AR</sub> and FcPhaC2 were inactivated. Therefore, the artificial PhaCs possessed improved thermal stability compared to PhaC<sub>AR</sub>. The four FcPhaCs synthesized poly(glycolate-<em>co</em>-3HB) [P(GL-<em>co</em>-3HB)] with a block sequence as well as PhaC<sub>AR</sub>. FcPhaC4 exhibited the highest GL fraction in P(GL-<em>co</em>-3HB) among the PhaCs tested. FcPhaC4 synthesized P(3HB)-<em>b</em>-P(2-hydroxybutyrate) and P(3HB)-<em>b</em>-polylactate, indicating its broad substrate scope. These results demonstrated the effectiveness of the FCD approach for creating sequence-regulating PHA synthases applicable to a wide range of polymer syntheses.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"236 ","pages":"Article 111295"},"PeriodicalIF":6.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562125","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}

引用次数: 0

Realizing balanced thermal safety and heat insulation in hydrophobic silica aerogel composites

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-26 DOI: 10.1016/j.polymdegradstab.2025.111294

Miao Liu , Yunli Huang , Chang Xu , Zhi Li , Shengjie Yao , Gaoxiang Long , Qiong Liu , Chuangang Fang , Xiaoxu Wu

Interest in high-performance multifunctional hydrophobic silica aerogels (HSAs) has generated extensive discussion around HSAs endowed with enhanced infrared radiation suppression and excellent flame retardancy. Herein, we propose an eco-friendly and low-cost strategy for fabricating fire safe and infrared radiative shielding HSAs for sustainable thermal insulation. The as-created FRSA-BN-0.2 aerogel composite demonstrated superior flame retardant properties, with reductions in peak of heat release rate, total heat release, and total smoke release of 18.8 %, 36.1 %, and 88.8 %, respectively, compared to those of pure HSA. Additionally, the initial thermal degradation temperature and the temperature of peak heat flow were markedly increased by 95.0 °C and 104.1 °C, respectively. Furthermore, the aerogel composite exhibited outstanding hydrophobicity (a water contact angle of 142.1°), excellent thermal insulation (a thermal conductivity of 23.2 mW/m·K), and substantial infrared shielding performance. In this study, commercial flame retardant 9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide (DOPO) was used as an acid catalyst substitute for strong acids, and boron nitride nanosheets were incorporated into the matrix to develop advanced multifunctional HSA aerogel composites. This material shows significant potential for application in fields such as aerospace, building insulation, and industrial thermal insulation.

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引用次数: 0

Mechanical recycling of HDPE-based packaging: Interplay between cross contamination, aging and reprocessing

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-25 DOI: 10.1016/j.polymdegradstab.2025.111290

Chiara Gnoffo , Rossella Arrigo , Alberto Frache

Achieving effective mechanical recycling strategies for polyolefins remains a major challenge for several reasons. Firstly, the thermo-mechanical degradation underwent during reprocessing, as well as the different degradation forms experienced during the service life, cause a severe modification of polyolefin microstructure, ultimately leading to a progressive deterioration of their performance. On the other hand, due to non-fully accurate sorting technologies, low levels of cross-contamination are commonly encountered in recycled polyolefins. All these features result in the obtainment recyclates with a heterogeneous and complex morphology, which significantly affects their final properties, often limiting their possible future applications. This work aims at addressing these issues, evaluating the combined effect of cross-contamination and of the degradation undergone by the polymers during service life and reprocessing for high-density polyethylene (HDPE) containing low amounts of polypropylene (PP) and polyethylene terephthalate (PET) as contaminants. In particular, pristine and cross-contaminated HDPE were subjected to photo-oxidative or thermo-oxidative treatments and the aged materials were reprocessed, aiming at simulating the real conditions of a typical mechanical recycling process. The obtained results demonstrated that cross-contamination minimises the functional degradation of HDPE, especially under photo-oxidative conditions. Conversely, the microstructural characterization pointed out that different microstructures can be achieved depending on the level of cross-contamination and on the aging treatment. Finally, it was shown that the presence of PP and PET as contaminants has a detrimental impact on the HDPE ductility, especially under thermo-oxidative conditions, while for photo-oxidised materials exerts a marginal role.

{"title":"Mechanical recycling of HDPE-based packaging: Interplay between cross contamination, aging and reprocessing","authors":"Chiara Gnoffo , Rossella Arrigo , Alberto Frache","doi":"10.1016/j.polymdegradstab.2025.111290","DOIUrl":"10.1016/j.polymdegradstab.2025.111290","url":null,"abstract":"<div><div>Achieving effective mechanical recycling strategies for polyolefins remains a major challenge for several reasons. Firstly, the thermo-mechanical degradation underwent during reprocessing, as well as the different degradation forms experienced during the service life, cause a severe modification of polyolefin microstructure, ultimately leading to a progressive deterioration of their performance. On the other hand, due to non-fully accurate sorting technologies, low levels of cross-contamination are commonly encountered in recycled polyolefins. All these features result in the obtainment recyclates with a heterogeneous and complex morphology, which significantly affects their final properties, often limiting their possible future applications. This work aims at addressing these issues, evaluating the combined effect of cross-contamination and of the degradation undergone by the polymers during service life and reprocessing for high-density polyethylene (HDPE) containing low amounts of polypropylene (PP) and polyethylene terephthalate (PET) as contaminants. In particular, pristine and cross-contaminated HDPE were subjected to photo-oxidative or thermo-oxidative treatments and the aged materials were reprocessed, aiming at simulating the real conditions of a typical mechanical recycling process. The obtained results demonstrated that cross-contamination minimises the functional degradation of HDPE, especially under photo-oxidative conditions. Conversely, the microstructural characterization pointed out that different microstructures can be achieved depending on the level of cross-contamination and on the aging treatment. Finally, it was shown that the presence of PP and PET as contaminants has a detrimental impact on the HDPE ductility, especially under thermo-oxidative conditions, while for photo-oxidised materials exerts a marginal role.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"236 ","pages":"Article 111290"},"PeriodicalIF":6.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520250","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}

引用次数: 0

Corrigendum to “Synthesis and characterization of eco-friendly chitosan-based waterborne polyurethanes and their ultraviolet degradation properties” [Polymer Degradation and Stability, 233 (2025) 111169]

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-22 DOI: 10.1016/j.polymdegradstab.2025.111253

Chun-Ta Wei , Jhu-Lin You , Kai-Yen Chin , Shu Mei Chang , Shun-Yi Jian , An-Yu Cheng

引用次数: 0

High-efficiency synergetic clustered triazinylphosphinate composite flame retardant system enhance fire resistance, smoke suppression, and resilience of flexible polyurethane foams

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2025-02-21 DOI: 10.1016/j.polymdegradstab.2025.111280

Yi Zhang , Wang Xi , Lijun Qian , Wei Tang , Lijie Qu , Jingyu Wang , Yong Qiu , Yajun Chen

Flexible polyurethane foams (FPUF) with superior flame retardancy, smoke suppression, and high resilience remain a significant challenge, particularly in achieving a limiting oxygen index (LOI) above 26%. To address this, a novel clustered aluminum triazinylphosphinate (CATP) was synthesized, and a ternary flame-retardant system (CED), comprising CATP, expandable graphite (EG), and dimethyl methylphosphonate (DMMP), was developed. The effects of CED on the flame retardancy, smoke suppression, and mechanical properties of FPUFs were systematically investigated. In flame retardancy, 20%CED/FPUF achieved an LOI of 29.1% and attained a UL-94 HF-1 rating in horizontal combustion tests, a notable milestone for flame-retardant FPUFs. Compared to neat FPUF, the peak heat release rate, total heat release, and total smoke release of 20%CED/FPUF were reduced by 67.2%, 60.0%, and 50.5%, respectively, with a remarkable char yield of 60.1%. These results significantly outperformed those of FPUF with 20% formulation based on commercial aluminum diethylphosphinate (ADP) (20%AED/FPUF). This highlights the ability of the CATP/EG/DMMP system to impart exceptional flame suppression and efficient charring effects to FPUFs. Moreover, CATP enhanced the cross-linking density of the FPUF matrix, increasing the tear strength of CED/FPUF from 560 N/m to 810 N/m while maintaining excellent foam resilience. In summary, this study offers a promising strategy for developing FPUFs with high LOI values, outstanding flame retardancy and smoke suppression, and robust mechanical properties.

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引用次数: 0