Pub Date : 2024-09-22DOI: 10.1016/j.polymdegradstab.2024.111017
Zsófia Kovács , Andrea Toldy
The increasing importance of thermoplastic composites, driven by their enhanced recyclability and production efficiency, has attracted interest in continuous fibre-reinforced thermoplastic. Polyamide 6 (PA6), synthesised via anionic ring-opening polymerisation, is particularly relevant, however, the flammability of PA6 poses significant challenges and a critical concern for their structural application, necessitating effective flame retardancy measures. This study investigates the development of flame retardant coatings for carbon fibre-reinforced PA6 composites, employing hexaphenoxycyclotriphosphazene (HPCTP) and expandable graphite (EG), and evaluates their efficacy in improving the flammability properties of the composites through their combined modes of action. We investigated the impact of FRs on glass transition temperature, crystallinity, thermal stability, monomer conversion and flammability properties. The best-performing formulations (PA6/3P%HPCTP/3%EG and PA6/3P%HPCTP/4%EG) were applied to the surface of carbon fibre-reinforced PA6 composites by in-mould coating. Due to the synergistic effect of HPCTP and EG, the coatings containing 3P% HPCTP and 3 % EG reduced the maximum heat release by 33 % and the total heat release by 37 %.
{"title":"Development of flame retardant coatings containing hexaphenoxycyclotriphosphazene and expandable graphite for carbon fibre-reinforced polyamide 6 composites","authors":"Zsófia Kovács , Andrea Toldy","doi":"10.1016/j.polymdegradstab.2024.111017","DOIUrl":"10.1016/j.polymdegradstab.2024.111017","url":null,"abstract":"<div><div>The increasing importance of thermoplastic composites, driven by their enhanced recyclability and production efficiency, has attracted interest in continuous fibre-reinforced thermoplastic. Polyamide 6 (PA6), synthesised via anionic ring-opening polymerisation, is particularly relevant, however, the flammability of PA6 poses significant challenges and a critical concern for their structural application, necessitating effective flame retardancy measures. This study investigates the development of flame retardant coatings for carbon fibre-reinforced PA6 composites, employing hexaphenoxycyclotriphosphazene (HPCTP) and expandable graphite (EG), and evaluates their efficacy in improving the flammability properties of the composites through their combined modes of action. We investigated the impact of FRs on glass transition temperature, crystallinity, thermal stability, monomer conversion and flammability properties. The best-performing formulations (PA6/3P%HPCTP/3%EG and PA6/3P%HPCTP/4%EG) were applied to the surface of carbon fibre-reinforced PA6 composites by in-mould coating. Due to the synergistic effect of HPCTP and EG, the coatings containing 3P% HPCTP and 3 % EG reduced the maximum heat release by 33 % and the total heat release by 37 %.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111017"},"PeriodicalIF":6.3,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326426","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 : 2024-09-21DOI: 10.1016/j.polymdegradstab.2024.111016
Mingming Yu , Zhimin Gao , Wang Xie , Xiaochao Shi , Ousheng Zhang , Zhigang Shen , Lin Fang , Musu Ren , Jinliang Sun
The oxidation state of phosphorus has a great influence on the flame retardant action of its flame retardants. In this study, a reactive phosphorus-containing flame retardant (POG-DOPO) with both low and high phosphorus oxidation states is synthesised and incorporated into epoxy resin. The results show that the part in high oxidation state act mainly in the condensed phase and the part in low oxidation state act mainly in the gas phase. Furthermore, the flame retardant exhibits a synergistic flame retardant effect, resulting in a higher flame retardant efficiency than that of flame retardants with a single phosphorus oxidation state. Compared with unmodified epoxy resin, the peak heat release rate, total heat release rate and total smoke release of POG-DOPO modified epoxy resin with only 3wt% phosphorus are reduced by 70.9%, 51.2% and 55.7%, respectively. Its LOI increases to 31.8% and vertical combustion test achieves UL-94 V-0 rating. This study provides a strategy for the structural design of efficient phosphorus-based flame retardants.
{"title":"A novel strategy utilizing oxidation states of phosphorus for designing efficient phosphorus-containing flame retardants and its performance in epoxy resins","authors":"Mingming Yu , Zhimin Gao , Wang Xie , Xiaochao Shi , Ousheng Zhang , Zhigang Shen , Lin Fang , Musu Ren , Jinliang Sun","doi":"10.1016/j.polymdegradstab.2024.111016","DOIUrl":"10.1016/j.polymdegradstab.2024.111016","url":null,"abstract":"<div><div>The oxidation state of phosphorus has a great influence on the flame retardant action of its flame retardants. In this study, a reactive phosphorus-containing flame retardant (POG-DOPO) with both low and high phosphorus oxidation states is synthesised and incorporated into epoxy resin. The results show that the part in high oxidation state act mainly in the condensed phase and the part in low oxidation state act mainly in the gas phase. Furthermore, the flame retardant exhibits a synergistic flame retardant effect, resulting in a higher flame retardant efficiency than that of flame retardants with a single phosphorus oxidation state. Compared with unmodified epoxy resin, the peak heat release rate, total heat release rate and total smoke release of POG-DOPO modified epoxy resin with only 3wt% phosphorus are reduced by 70.9%, 51.2% and 55.7%, respectively. Its LOI increases to 31.8% and vertical combustion test achieves UL-94 V-0 rating. This study provides a strategy for the structural design of efficient phosphorus-based flame retardants.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111016"},"PeriodicalIF":6.3,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359073","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}
This article presents the different flame retardant (FR) additives adapted to polypropylene (PP) and their mode of actions when incorporated into the bulk. PP is naturally highly flammable; this review highlights the challenges to improve its flame retardant properties. It first reports the thermal degradation of PP and then focuses on FR PP systems and shows the high flame retardancy effectiveness of intumescent flame retardant (IFR) systems providing an efficient protective layer. It also highlights the need to improve the IFR systems to reduce the amount of FRs, using synergists, bio-based compounds or modified additives, but also using other effective systems such as free radical generators systems in combination with phosphorous flame retardant agent. Therefore, this article explores the effectiveness of several FR systems and highlight their mechanism of action in PP.
{"title":"Flame-retardants for polypropylene: A review","authors":"Séverine Bellayer , Melvin Dilger , Sophie Duquesne , Maude Jimenez","doi":"10.1016/j.polymdegradstab.2024.111008","DOIUrl":"10.1016/j.polymdegradstab.2024.111008","url":null,"abstract":"<div><p>This article presents the different flame retardant (FR) additives adapted to polypropylene (PP) and their mode of actions when incorporated into the bulk. PP is naturally highly flammable; this review highlights the challenges to improve its flame retardant properties. It first reports the thermal degradation of PP and then focuses on FR PP systems and shows the high flame retardancy effectiveness of intumescent flame retardant (IFR) systems providing an efficient protective layer. It also highlights the need to improve the IFR systems to reduce the amount of FRs, using synergists, bio-based compounds or modified additives, but also using other effective systems such as free radical generators systems in combination with phosphorous flame retardant agent. Therefore, this article explores the effectiveness of several FR systems and highlight their mechanism of action in PP.</p></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111008"},"PeriodicalIF":6.3,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271384","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 : 2024-09-20DOI: 10.1016/j.polymdegradstab.2024.111011
Yuya Fukata, Satoshi Kimura, Tadahisa Iwata
Printed circuit boards (PCBs) contain metals and plastics, with the latter often incinerated after disposal, leading to carbon dioxide emissions. This study focuses on developing biomass-based thermosetting resins derived from polysaccharides. Cellulose and α-1,3-glucan were introduced with unsaturated (2-butenoate) and saturated (hexanoate) ester groups to achieve appropriate properties for PCB applications. The synthesized polysaccharide esters, cellulose-2-butenoate-hexanoate and α-1,3-glucan-2-butenoate-hexanoate, demonstrated thermoformability at 150 °C, suitable for being laminated on circuit lines. After heating at 220 °C for 1 hour, the unsaturated parts of the polymers crosslinked, increasing the glass transition temperature to over 230 °C, making them potentially durable for the soldering process. The dielectric constant and dissipation factor of the crosslinked resins ranged from 2.5 to 2.7 and 0.012 to 0.014, respectively, outperforming conventional epoxy resins to reduce transmission loss. Additionally, the crosslinked films exhibited robust mechanical properties with tensile strengths exceeding 50 MPa. These results indicate that polysaccharide unsaturated esters are promising for use as PCB insulating resins, providing a sustainable alternative to petroleum-based materials.
{"title":"Low-dielectric thermosetting resins derived from polysaccharide unsaturated esters","authors":"Yuya Fukata, Satoshi Kimura, Tadahisa Iwata","doi":"10.1016/j.polymdegradstab.2024.111011","DOIUrl":"10.1016/j.polymdegradstab.2024.111011","url":null,"abstract":"<div><div>Printed circuit boards (PCBs) contain metals and plastics, with the latter often incinerated after disposal, leading to carbon dioxide emissions. This study focuses on developing biomass-based thermosetting resins derived from polysaccharides. Cellulose and α-1,3-glucan were introduced with unsaturated (2-butenoate) and saturated (hexanoate) ester groups to achieve appropriate properties for PCB applications. The synthesized polysaccharide esters, cellulose-2-butenoate-hexanoate and α-1,3-glucan-2-butenoate-hexanoate, demonstrated thermoformability at 150 °C, suitable for being laminated on circuit lines. After heating at 220 °C for 1 hour, the unsaturated parts of the polymers crosslinked, increasing the glass transition temperature to over 230 °C, making them potentially durable for the soldering process. The dielectric constant and dissipation factor of the crosslinked resins ranged from 2.5 to 2.7 and 0.012 to 0.014, respectively, outperforming conventional epoxy resins to reduce transmission loss. Additionally, the crosslinked films exhibited robust mechanical properties with tensile strengths exceeding 50 MPa. These results indicate that polysaccharide unsaturated esters are promising for use as PCB insulating resins, providing a sustainable alternative to petroleum-based materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111011"},"PeriodicalIF":6.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359070","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 : 2024-09-20DOI: 10.1016/j.polymdegradstab.2024.111014
Dávid Zoltán Pirityi , Tamás Bárány , Kornél Pölöskei
Thermomechanical devulcanization is a possible solution for the circular economy of EPDM rubber, as it removes covalent crosslinks from vulcanizates, resulting in a material similar to uncured rubber mixes. In this paper, sulfur-cured EPDM rubber was treated with thermomechanical stimuli: a) processing on a two-roll mill and in an internal mixer, and b) twin-screw extrusion. Horikx's analysis indicated a 75 % decrease in crosslink density with little polymer chain degradation. The resulting devulcanizates and non-devulcanized rubber crumb were added to the original rubber mix, yielding samples with 0, 25, 50, 75 and 100 wt% recycled rubber contents. Revulcanizates with up to 50 wt% devulcanizate content retained the tensile strength of the original rubber with a slight increase in modulus. Ultimately, batch devulcanization had the most promising results, and extrusion devulcanization was also more beneficial than using non-devulcanized rubber crumb. Crosslink density and morphological tests also support these findings.
{"title":"Recycling of EPDM rubber via thermomechanical devulcanization: Batch and continuous operations","authors":"Dávid Zoltán Pirityi , Tamás Bárány , Kornél Pölöskei","doi":"10.1016/j.polymdegradstab.2024.111014","DOIUrl":"10.1016/j.polymdegradstab.2024.111014","url":null,"abstract":"<div><div>Thermomechanical devulcanization is a possible solution for the circular economy of EPDM rubber, as it removes covalent crosslinks from vulcanizates, resulting in a material similar to uncured rubber mixes. In this paper, sulfur-cured EPDM rubber was treated with thermomechanical stimuli: a) processing on a two-roll mill and in an internal mixer, and b) twin-screw extrusion. Horikx's analysis indicated a 75 % decrease in crosslink density with little polymer chain degradation. The resulting devulcanizates and non-devulcanized rubber crumb were added to the original rubber mix, yielding samples with 0, 25, 50, 75 and 100 wt% recycled rubber contents. Revulcanizates with up to 50 wt% devulcanizate content retained the tensile strength of the original rubber with a slight increase in modulus. Ultimately, batch devulcanization had the most promising results, and extrusion devulcanization was also more beneficial than using non-devulcanized rubber crumb. Crosslink density and morphological tests also support these findings.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111014"},"PeriodicalIF":6.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319135","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 : 2024-09-20DOI: 10.1016/j.polymdegradstab.2024.111015
Jinyan Li, Yang Yu, Xiaolin Zhang
The design and development of biobased plastics that can degrade in seawater is a potential approach to address the seawater pollution of fossil plastics. Herein, N,N'-pentamethylene-bis(pyrrolidone-4-methyl carboxylate) (PBPC), a biobased diester with two pyrrolidone rings, was synthesized from renewable 1,5-pentanediamine and dimethyl itaconate. PBPC was polymerized with three α,ω-diols to prepare biobased homopolyesters with number-average molecular weight (Mn) around 25 kDa. These amorphous homopolyesters presented remarkable UV shielding abilities compared with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS). Incubation experiments in artificial seawater for 150 days indicated that the homopolyesters based on PBPC exhibited rapid seawater-degradability. Then, PBPC was copolymerized with 1,4-butanediol and terephthalic acid to prepare a series of copolyesters with Mn around 20 kDa. The introduction of PBPC into poly(butylene terephthalate) (PBT) resulted in the elevated toughness and sensitivity to seawater degradation. Depending on the composition of PBPC, the thermal, mechanical, and degradation rate of the copolyesters were adjustable. Overall, the PBPC-based polyesters are promising alternatives to commercial packaging materials in improving the renewability of raw materials and achieving seawater degradation.
{"title":"Synthesis of renewable and seawater-degradable polyesters based on a fully biobased diester","authors":"Jinyan Li, Yang Yu, Xiaolin Zhang","doi":"10.1016/j.polymdegradstab.2024.111015","DOIUrl":"10.1016/j.polymdegradstab.2024.111015","url":null,"abstract":"<div><div>The design and development of biobased plastics that can degrade in seawater is a potential approach to address the seawater pollution of fossil plastics. Herein, <em>N,N</em>'-pentamethylene-bis(pyrrolidone-4-methyl carboxylate) (PBPC), a biobased diester with two pyrrolidone rings, was synthesized from renewable 1,5-pentanediamine and dimethyl itaconate. PBPC was polymerized with three α,ω-diols to prepare biobased homopolyesters with number-average molecular weight (<em>M</em><sub>n</sub>) around 25 kDa. These amorphous homopolyesters presented remarkable UV shielding abilities compared with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS). Incubation experiments in artificial seawater for 150 days indicated that the homopolyesters based on PBPC exhibited rapid seawater-degradability. Then, PBPC was copolymerized with 1,4-butanediol and terephthalic acid to prepare a series of copolyesters with <em>M</em><sub>n</sub> around 20 kDa. The introduction of PBPC into poly(butylene terephthalate) (PBT) resulted in the elevated toughness and sensitivity to seawater degradation. Depending on the composition of PBPC, the thermal, mechanical, and degradation rate of the copolyesters were adjustable. Overall, the PBPC-based polyesters are promising alternatives to commercial packaging materials in improving the renewability of raw materials and achieving seawater degradation.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111015"},"PeriodicalIF":6.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314157","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 : 2024-09-19DOI: 10.1016/j.polymdegradstab.2024.111012
Xiaodi Ye , Cheng Zhan , Bingtao Wang , Ting Sai , Chengfeng Zhang , Juan Li , Zhenghong Guo , Siqi Huo
To cope with the practical demands of high-performance polycarbonate (PC) and explore the application of carbon black (CB) in flame retardant field, a sulfonated carbon black (CB-SS) was synthesized and applied to flame retardant PC in this work. Compared with PC/CB composite, PC/CB-SS composite displays better overall performances under the same flame retardant addition. The PC/3CB-SS composite with 3 wt.% of CB-SS achieves a vertical burning test (UL-94) V-0 rating with a limiting oxygen index (LOI) of 29.5%, and its peak heat release rate (PHRR) and total smoke release rate (TSR) are respectively reduced by 17% and 6% relative to those of PC/3CB with 3 wt.% of CB. The flame retardancy mechanism is proposed by analyzing the char residue obtained from cone calorimetry test, which confirms the synergistic flame-retardant effect between sodium sulfonate and CB in condensed phase. Moreover, PC/3CB-SS shows much better mechanical properties than PC/3CB, and its elongation at break is increased by 223% compared with that of PC/3CB. This is mainly due to the more even dispersion of CB-SS within PC and the stronger interfacial force between CB-SS and PC. This work provides an effective approach for the creation of fire-retardant and smoke-suppressive PC composites with well-preserved mechanical properties, contributing to expanding the industrial applications of PC.
{"title":"Engineering sulfonated carbon black for flame-retardant and smoke-suppressive polycarbonate with well-preserved mechanical performances","authors":"Xiaodi Ye , Cheng Zhan , Bingtao Wang , Ting Sai , Chengfeng Zhang , Juan Li , Zhenghong Guo , Siqi Huo","doi":"10.1016/j.polymdegradstab.2024.111012","DOIUrl":"10.1016/j.polymdegradstab.2024.111012","url":null,"abstract":"<div><div>To cope with the practical demands of high-performance polycarbonate (PC) and explore the application of carbon black (CB) in flame retardant field, a sulfonated carbon black (CB-SS) was synthesized and applied to flame retardant PC in this work. Compared with PC/CB composite, PC/CB-SS composite displays better overall performances under the same flame retardant addition. The PC/3CB-SS composite with 3 wt.% of CB-SS achieves a vertical burning test (UL-94) V-0 rating with a limiting oxygen index (LOI) of 29.5%, and its peak heat release rate (PHRR) and total smoke release rate (TSR) are respectively reduced by 17% and 6% relative to those of PC/3CB with 3 wt.% of CB. The flame retardancy mechanism is proposed by analyzing the char residue obtained from cone calorimetry test, which confirms the synergistic flame-retardant effect between sodium sulfonate and CB in condensed phase. Moreover, PC/3CB-SS shows much better mechanical properties than PC/3CB, and its elongation at break is increased by 223% compared with that of PC/3CB. This is mainly due to the more even dispersion of CB-SS within PC and the stronger interfacial force between CB-SS and PC. This work provides an effective approach for the creation of fire-retardant and smoke-suppressive PC composites with well-preserved mechanical properties, contributing to expanding the industrial applications of PC.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111012"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314163","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 : 2024-09-19DOI: 10.1016/j.polymdegradstab.2024.111013
Xiao-Hui Shi , Huan Luo , Cheng-Yue Jing , Hong Shi , De-Yi Wang
Inspired by the significant synergistic effect of transition metals and ammonium polyphosphate (APP) on flame reatrdancy, a nickel/cobalt-layered double hydroxide derived from a selected zeolitic imidazolate framework-67 (APP@NiCo) was constructed onto the surface of APP to enhance the fire safety of thermoplastic polyurethane (TPU). The results demonstrated that TPU containing 6 wt% APP@NiCo exhibited a LOI value of 27.7 % and achieved UL-94 V-0 rating. Furthermore, there was a significant reduction in the peak heat release rate, heat release rate, and total smoke production by 72.8 %, 37.5 % and 56.9 %, respectively. The remarkable improvement in flame retardancy was contributed to the highly synergistic charring catalysis of APP and dual transition metals cobalt and nickel, which effectively promoted the formation of robust char layers during TPU combustion for enhancing fire safety.
{"title":"The preparation of ammonium polyphosphate@ nickel/cobalt-layered double hydroxide and its application as flame retardant in thermoplastic polyurethane","authors":"Xiao-Hui Shi , Huan Luo , Cheng-Yue Jing , Hong Shi , De-Yi Wang","doi":"10.1016/j.polymdegradstab.2024.111013","DOIUrl":"10.1016/j.polymdegradstab.2024.111013","url":null,"abstract":"<div><div>Inspired by the significant synergistic effect of transition metals and ammonium polyphosphate (APP) on flame reatrdancy, a nickel/cobalt-layered double hydroxide derived from a selected zeolitic imidazolate framework-67 (APP@NiCo) was constructed onto the surface of APP to enhance the fire safety of thermoplastic polyurethane (TPU). The results demonstrated that TPU containing 6 wt% APP@NiCo exhibited a LOI value of 27.7 % and achieved UL-94 V-0 rating. Furthermore, there was a significant reduction in the peak heat release rate, heat release rate, and total smoke production by 72.8 %, 37.5 % and 56.9 %, respectively. The remarkable improvement in flame retardancy was contributed to the highly synergistic charring catalysis of APP and dual transition metals cobalt and nickel, which effectively promoted the formation of robust char layers during TPU combustion for enhancing fire safety.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111013"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319134","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 : 2024-09-19DOI: 10.1016/j.polymdegradstab.2024.111010
Zhaoshun Zhan , Shihan Weng , Tianyou Bao , Lina Yan , Fanna Meng , Lixin Li
Currently, it is still a challenge to endow polylactic acid (PLA) with excellent degradation and fire safety. In this work, we have extracted a novel phosvitin aiming to achieve the fire resistance and degradation of PLA. Employing the phosvitin, the PLA composite exhibits conspicuous fire resistance with an LOI of 27.4 % and a V-0 rating in the UL-94 tests by controlling the added volume at 40 wt.%. Simultaneously, the thermal stability and fire behaviour of the PLA composite have been improved by the plentiful char residue formation. The flame-retardant mechanism of phosvitin in PLA material has been deduced by TG-IR, FTIR XPS and SEM. The phosvitin containing abundant P-O, P = O and P-N functional groups generates phosphorus-containing compounds to promote the dehydration reaction of the PLA matrix in a condensed phase. This is beneficial to improve the flame retardancy of PLA by the formation of a char layer, providing the shielding effect to prevent the heat transfer and flammable micro-molecules volatilisation process. Likewise, the affluent phosphorus-containing compounds included in the phosvitin possess fabulous catalytic action to destroy the PLA into small molecular weight fragment which shows a beneficial to promote the degradation reaction of PLA composite. Hence, the phosvitin is important to expand the range of applications of PLA materials to develop sustainable multifunctional materials.
{"title":"Simultaneously boosting the flame retardancy and degradability of poly(lactic acid) composite by phosvitin affiliation","authors":"Zhaoshun Zhan , Shihan Weng , Tianyou Bao , Lina Yan , Fanna Meng , Lixin Li","doi":"10.1016/j.polymdegradstab.2024.111010","DOIUrl":"10.1016/j.polymdegradstab.2024.111010","url":null,"abstract":"<div><div>Currently, it is still a challenge to endow polylactic acid (PLA) with excellent degradation and fire safety. In this work, we have extracted a novel phosvitin aiming to achieve the fire resistance and degradation of PLA. Employing the phosvitin, the PLA composite exhibits conspicuous fire resistance with an LOI of 27.4 % and a V-0 rating in the UL-94 tests by controlling the added volume at 40 wt.%. Simultaneously, the thermal stability and fire behaviour of the PLA composite have been improved by the plentiful char residue formation. The flame-retardant mechanism of phosvitin in PLA material has been deduced by TG-IR, FTIR XPS and SEM. The phosvitin containing abundant P-O, <em>P</em> = <em>O</em> and P-N functional groups generates phosphorus-containing compounds to promote the dehydration reaction of the PLA matrix in a condensed phase. This is beneficial to improve the flame retardancy of PLA by the formation of a char layer, providing the shielding effect to prevent the heat transfer and flammable micro-molecules volatilisation process. Likewise, the affluent phosphorus-containing compounds included in the phosvitin possess fabulous catalytic action to destroy the PLA into small molecular weight fragment which shows a beneficial to promote the degradation reaction of PLA composite. Hence, the phosvitin is important to expand the range of applications of PLA materials to develop sustainable multifunctional materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111010"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311563","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 : 2024-09-18DOI: 10.1016/j.polymdegradstab.2024.111009
Tengfei Han , Yanshai Wang , Shufen Zhang , Benzhi Ju
Cellulose is the most abundant natural polypolysaccharide and is an ideal raw material to replace petroleum-based plastics. However, natural cellulose is difficult to be thermo-processed like conventional plastics because of the rich and strong hydrogen bonds interactions. In this study, a series of dialdehyde derivatives of cellulose (DACs) were prepared by periodate oxidation of cellulose, and cellulose covalent adaptive networks based on acetal dynamic covalent bonds (ACCs) were prepared using dipentaerythritol as a crosslinker for DAC. This strategy can introduce acetal bonds, weaken hydrogen bonds, and reduce rigidity to kill three birds with one stone. The excellent reprocessing performance of ACCs is attributed to the reconstruction of the cellulose hydrogen bond network by acetal bonds, and the reversible exchange reaction of the acetal bonds at high temperatures endows the cellulose chains with mobility, allowing ACCs to be remodeled by hot pressing at 90°C for 15 min. The excellent stability and reprocessability of ACCs hold the promise of replacing current non-renewable petroleum-based plastics and provide inspiration for the development of other types of biomass plastics.
{"title":"“Three birds with one stone” strategy for building easily reprocessable cellulosic thermosetting resins","authors":"Tengfei Han , Yanshai Wang , Shufen Zhang , Benzhi Ju","doi":"10.1016/j.polymdegradstab.2024.111009","DOIUrl":"10.1016/j.polymdegradstab.2024.111009","url":null,"abstract":"<div><div>Cellulose is the most abundant natural polypolysaccharide and is an ideal raw material to replace petroleum-based plastics. However, natural cellulose is difficult to be thermo-processed like conventional plastics because of the rich and strong hydrogen bonds interactions. In this study, a series of dialdehyde derivatives of cellulose (DACs) were prepared by periodate oxidation of cellulose, and cellulose covalent adaptive networks based on acetal dynamic covalent bonds (ACCs) were prepared using dipentaerythritol as a crosslinker for DAC. This strategy can introduce acetal bonds, weaken hydrogen bonds, and reduce rigidity to kill three birds with one stone. The excellent reprocessing performance of ACCs is attributed to the reconstruction of the cellulose hydrogen bond network by acetal bonds, and the reversible exchange reaction of the acetal bonds at high temperatures endows the cellulose chains with mobility, allowing ACCs to be remodeled by hot pressing at 90°C for 15 min. The excellent stability and reprocessability of ACCs hold the promise of replacing current non-renewable petroleum-based plastics and provide inspiration for the development of other types of biomass plastics.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111009"},"PeriodicalIF":6.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311562","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}