POLYMER DEGRADATION AND STABILITY
·
2015
·
IF 3.163
Weihua Xu,Alvianto Wirasaputra,Shumei Liu,Yanchao Yuan,Jianqing Zhao
A highly effective 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based flame retardant (D-bp) was successfully synthesized via the addition reaction between DOPO and Schiff-base obtained in advance by the condensation of 4,4’-diaminodiphenyl methane (DDM) and 4-hydroxybenzaldehyde. D-bp was used as co-curing agent to improve the flame retardancy of DDM/diglycidyl ether of bisphenol A (DGEBA) system. Non-isothermal curing kinetics, thermal and flame-retardant properties of cured epoxy resins were studied by differential scanning calorimeter (DSC), thermogravimeric analysis (TGA), UL94 vertical burning test, limited oxygen index (LOI) and cone calorimeter test. The morphology of residues after cone calorimeter test was observed by scanning electron microscope (SEM). The results revealed that the epoxy thermosets exhibited excellent flame-retardancy and passed V-0 rating of UL 94 test with LOI of 39.7% when the phosphorus content was only 0.5 wt%.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Beitao Liu,Jiahui Li,Cijian Zhang,Yibo Wang,Xigao Jian,Zhihuan Weng
Environmental economics is intensifying the necessity for the advancement of recycling technologies to address the increasing volume of discarded thermoset polymers. Covalent adaptable networks (CANs) provide a new strategy for the recycling and functionalization of thermosetting resins. Herein, a carvone-based CAN is developed, in which thermally driven depolymerization of mechanically robust polymer networks is achieved by dynamic thiol-Michael bonds. The original cross-linking network can be retained through simple drying and hot-pressing steps without purifying degradation products. The reversibility of the thiol-Michael group is demonstrated and the CAN exhibits shape memory behaviors triggered by human body temperature. We propose a micro-robotic injection model with good mechanical strength and fast response speed for complex 1D to 3D shape morphing in aqueous media at 37 °C. Our findings present a high-quality strategy to realize recycling and functionalization of bio-based thermoset resins and expand the toolbox for the preparation of bio-based CANs with thermo-responsive behavior.
研究领域:
材料科学
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聚合物化学
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可持续材料
·
回收技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2023
·Vol. 31
·期 8
·3573-3584
·
IF 5.3
Chen Zixuan,Sun Fei,Zhao Huakun,Yu Tao,Yang Weidong,Li Qian,Li Yan
Poly (lactic acid) (PLA) is a bio-based polymer that is derived from renewable plant resources, such as corn, cassava, and other crops. It has a wide range of potential applications. However, currently, the PLA produced on an industrial scale is a thermoplastic polymer, which has poor mechanical strength and poor flame retardancy. These mediocre properties limit its potential uses in housings, structural interior of automotives, and packaging. The present study aimed to overcome the limitations of thermoplastic PLA by developing a synthesis route for producing thermosetting PLA with improved flame retardancy. The synthesis involved reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with itaconic acid (IA), polymerizing the product with pentaerythritol (PENTA) and lactic acid (LA) oligomer, and end-functionalizing with methacrylic anhydride (MAAH). The success of the synthesis was confirmed by analyzing the results of Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR) analysis. The curing kinetics is elaborated by Kissinger’s and Crane’s methods with outstanding fitting. Increasing the LA-to-PENTA ratio results in higher molecular weight and larger arm length, leading to less crosslinking density and lower phosphorus content. A 10:1 LA-to-PENTA mole ratio contributes to UL-94 V1 ranking, 24% limit oxygen index (LOI), 183 kJ/g heat release capacity (HRC), and 21.4 kJ/g total heat release (THR) indicating the admirable flame retardancy. The development of flame-retardant thermosetting PLA could be a significant step forward in expanding its potential applications and improving its properties.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Dengkang Guo,Wenting Ren,Sisi Yao,Jingpeng Li,Yan Yu,Fuxiang Chu
Reckoning with the global environmental challenge of plastic pollution, particularly in terms of recycling and biodegradation of thermosetting plastics, sustainable alternatives are imperative. The rapidly growing and eco-friendly material bamboo has great potential as a sustainable resource; however, it lacks the inherent self-bonding and plasticity characteristics found in plastics. This study presents a feasible approach to enhance the plasticity of bamboo by selectively removing part of its lignin and disrupting the crystalline structure of cellulose. Concurrently, this process selectively transforms hydroxyl groups into highly reactive dialdehyde groups to increase the reactivity of bamboo. The resulting activated bamboo units undergo a hot-pressing process to transform them into a type of thermosetting plastic (ABTP). The ABTP is highly moldable, and its color can be precisely regulated by adjusting the lignin content. Additionally, it exhibits exceptional solvent and water resistance, along with notable mechanical properties, including a tensile strength of 50 MPa, flexural strength of 80 MPa, flexural modulus of 5 GPa, and Shore D hardness approaching 90. Furthermore, the bamboo-derived plastic exhibits exceptional reusability and biodegradability, presenting feasible and environmentally friendly alternatives to conventional plastics while harnessing the sustainable development potential of bamboo.
研究领域:
材料科学
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环境科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2015
·Vol. 17
·期 4
·2383-2392
·
IF 8.02
Jinyue Dai,Songqi Ma,Yonggang Wu,Lijing Han,Lisheng Zhang,Jin Zhu,Xiaoqing Liu
A series of bio-based polyesters were synthesized by melt polycondensation of itaconic acid with diols and glycerol without VOC emission. Their chemical structures were confirmed by FT-IR and 1H-NMR before they were made to copolymerize with acrylated epoxidized soybean oil (AESO). The thermal and mechanical properties of the resulting thermosets were investigated by differential scanning calorimetry (DSC), tensile testing and dynamic mechanical analysis (DMA). Their coating properties on tinplate and glass plate were also studied. Results showed that the tensile strength, modulus, glass transition temperatures and bio-based content of the AESO-based thermosetting resins were significantly improved after the introduction of the synthesized polyesters. In addition, the modified AESO systems could be well coated on the surface of tinplate and glass plate and good coating properties such as hardness, flexibility, adhesion, solvent resistance and water absorption were demonstrated. They showed great potential for applications as coatings, adhesives and composites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Langlang Dai,Yuehong Zhang,Fei Ma,Tuo Ji,Lei Zhang,Bin Lyu
In order to reduce dependence on petroleum resources, three different biobased epoxy monomers (Eu-EP-1, Eu-EP-2, and Eu-EP-3) with a biobased carbon content of 76.9%–83.3% were prepared from eugenol, which can be derived from lignin. Three eugenol-based epoxy thermosets (Eu-EP-1/IPDA, Eu-EP-2/IPDA, and Eu-EP-3/IPDA) were then obtained by curing Eu-EP monomer with a commercial IPDA (isophorone diamine) hardener; the curing activation energy was in the range of 37.4–48.2 kJ/mol, the gel content ranged from 95.4%–96.5%, and the cross-linking degree reached 1185–2119 mol/m3, confirming that Eu-EP and IPDA were cured to form cross-linking network structures. Therefore, the Eu-EP/IPDA thermosets had excellent in-service performance with a Tg of 63.9–76.3 °C and a tensile strength of 34.7–43.1 MPa. However, the Eu-EP/IPDA thermosets with permanent chemical bonds were difficult to recycle. Since Eu-EP-2/IPDA had balanced performance, Eu-EP-2 was selected to develop recyclable Eu-EP/AFD epoxy vitrimers by curing with AFD (4,4′-dithiodiphenylamine). The resulting Eu-EP-2/AFD1.00 epoxy vitrimer had a Tg of 79.4 °C and a tensile strength of 39.2 MPa, and the remodeling of the Eu-EP-2/AFD1.00 epoxy vitrimer could be achieved by hot pressing at 200 °C for 6 h; the self-healing of the scratched material could be achieved by heating at 180 °C for 2 h, and the Eu-EP-2/AFD1.00 epoxy vitrimer could be dissolved in mercaptoethanol. Therefore, Eu-EP is a potential sustainable epoxy monomer for the development of epoxy materials with a balanced in-service performance and recyclability. This study offers a facile solution for the development of sustainable eugenol-based epoxy materials.
研究领域:
材料科学
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化学工程
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可持续发展
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 136
·期 12
·47231
·
IF 1.901
Da Shen,Li Yuan,Guozheng Liang,Aijuan Gu,Qingbao Guan
The development of an energy-efficient strategy to prepare thermally resistant damping materials with high damping capacities (tan δ values) and broad effective damping temperature ranges (Δ T s) at high temperatures (>150 °C) is still an interesting challenge. In this study, a graft copolymer (PSi- g -APPO) was synthesized through the reaction between hydrogen-terminated fluorosilicone and allyl poly(phenylene oxide) (APPO), and a unique kind of photocrosslinkable film (coded as GFA) consisting of FSR, APPO and PSi- g -APPO was prepared. The resultant GFA has high thermal resistance, wide Δ T , and high tan δ. When the weight ratio of APPO to FSR to PSi- g -APPO was 81:9:10, the obtained film exhibited a broad Δ T of 64 °C and a high tan δ (≤1.01) from 157 to 221 °C; this was the best comprehensive performance among the GFA systems. The mechanism behind the excellent integrated performance of GFA was studied and was proven to be due to the unique structure of the heterogeneous GFA system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47231.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 25
·15420-15431
·
IF 10.733
Xiwei Xu,Songqi Ma,Jiahui Wu,Jintao Yang,Binbo Wang,Sheng Wang,Qiong Li,Jie Feng,Shusen You,Jin Zhu
Two diepoxides containing a two-benzene-ring-conjugated Schiff base when cured with an aromatic diamine result in high-performance thermosets combining excellent controlled degradability, stability and antibacterial properties. Epoxy resins have been widely used in coatings, adhesives, composites, electronic packaging materials, etc., but they are arduous to recycle and have no antibacterial activity. In this paper, two-benzene-ring-conjugated Schiff base diepoxy monomers were synthesized and further cross-linked with 4,4-diaminodiphenylmethane. The chemical structures of the diepoxides as well as their thermosets were characterized in detail. The property investigation manifested that the thermosets possessed a far higher glass transition temperature of ∼206 °C, tensile strength of ∼122 MPa, and tensile modulus of ∼2646 MPa than a commonly used high-performance bisphenol A epoxy resin. Moreover, they possessed excellent acidity and temperature-controlled degradability, and superior stability in common solvents, thermal treatment and hygrothermal aging. Furthermore, they presented excellent coating properties (including hardness, adhesion, and solvent resistance) and antibacterial properties with a bactericidal capability of ∼91%.
研究领域:
材料科学
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化学工程
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 51
·29788-29795
·
IF 3.049
Fei Fu,Dan Wang,Minggui Shen,Shibin Shang,Zhanqian Song,Jie Song
Development of bio-based polymers has been promoted by the growing concerns about the long-term sustainability and negative environmental footprint of petroleum-based polymer materials. A new monomer containing benzocyclobutene and allyl units has been developed by using rosin as the feedstock. The structure of the monomer was characterized by elemental analysis, MS, FT-IR and NMR spectroscopy. The monomer could be converted to the polymer via thermal ring-opening polymerization which was characterized via FT-IR, thermogravimetric analysis (TGA), atom force microscopy (AFM) and so on. The polymer showed good dielectric properties and hydrophobicity with an average dielectric constant of 2.51 in a range of frequencies from 0.1 to 18 MHz and a water contact angle of 106°. In addition, the polymer with other comprehensive performances exhibited a 5% weight loss temperature of 406 °C, a surface roughness (Ra) of 0.658 nm in a 5.0 × 5.0 μm2 area, hardness and Young's modulus of 0.283 and 3.542 GPa, and storage modulus of 11.46 GPa at 30 °C. These data suggest that the polymer may have potential application in electronics and microelectronics.
研究领域:
材料科学
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生物基化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Laihui Xiao,Shuai Li,Yigang Wang,Wenbin Li,Jie Chen,Jinrui Huang,Xiaoan Nie
Thermosets of the diglycidyl ether of bisphenol A (DGEBA) are normally brittle owing to its rigid structure. To address this problem, a bioinspired strategy to form sacrificial bonds in a curing system, which may enhance the flexibility of epoxy thermosets and maintain a favorable strength simultaneously has been proposed. A tung (Aleurites montana L.) oil diglyceride based-acid (TODGA) that may construct sacrificial bonds with the epoxy matrix in the form of π-π interactions was prepared, and was added into a DGEBA / polyetheramine curing system at varying ratios. TODGA can greatly improve the flexibility and toughness of epoxy thermosets. At the addition of 7.5 wt%, the elongation at break, toughness, and impact strength are improved from 5.9 % to 86.6 %, from 2.1 to 19.0 MJ m −3 , and from 4.3 to 5.9 kJ·m −2 respectively, while the tensile strength is maintained at 34.8 MPa. In comparison, the toughening effect of TODGA outperforms that of commercial epoxidized soybean (Glycine max (L.) Merr.) oil. Although TODGA is a flexible modifier, it does not significantly decrease glass transition temperature and thermal stability. These results demonstrate that fabricating sacrificial bonds is a practical way to toughen epoxy thermosets, and TODGA can be potentially utilized as a commercial toughening agent.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2022
·Vol. 24
·期 4
·1561-1569
·
IF 11.034
Peixuan Wu,Xinchao Wang,Ruhui Shi,Haiyang Cheng,Fengyu Zhao
The synthesis of self-healing and recyclable polymeric materials from renewable CO2 is of great importance in the fields of functional materials and sustainable chemistry. In this work, mechanically robust poly(urea-imine) (PUI) thermosets were prepared from CO2-sourced oligourea (OUa), terephthalaldehyde (TA) and tri(2-aminoethyl)amine (TAEA) through condensation between equimolar amino and aldehyde groups. The synthesized PUIs have satisfactory mechanical performance, seal-healing and recyclable properties as they contain cross-linked dynamic imine bonds and reversible hydrogen bonds. These properties can be adjusted by changing the ratio of TAEA to OUa, thus varying the chemical bonds and chain structure. The highest values for the mechanical properties tensile stress (10.2 MPa) and Young's modulus (79 MPa) were obtained in a PUI thermoset synthesized from a molar ratio of TAEA to OUa of 3 : 2 (OUa2-T3). In addition, this thermoset can be healed at 80 °C with a healing efficiency over 92% owing to the high reversibility of imine and hydrogen bonds and the flexibility of CO2-sourced OUa chains. Moreover, it can also be reprocessed and recycled by physical and/or chemical means without change in its chemical structure, glass transition temperature and original mechanical properties. Additionally, this PUI thermoset can be easily degraded into its original reagents OUa, TA and TAEA under acid conditions. Therefore, as novel sustainable materials, the PUI thermosets reported in this article have great potential to replace conventional non-degradable thermosets over a wide field.
研究领域:
材料科学
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 9
·3944
·
IF 4.6
Yin Lu,Yaliang Peng,Yi Yang,Jiahao Liu,Kan Zhang
There is an urgency to produce novel high-performance resins to support the rapid development of the aerospace field and the electronic industry. In the present work, we designed and consequently synthesized a benzoxazine monomer (oHPNI-fa) bearing both norbornene and furan groups through the flexible benzoxazine structural design capability. The molecular structure ofoHPNI-fawas verified by the combination characterization of nuclear magnetic resonance spectrum, FT-IR technology, and high-resolution mass spectrum. The thermally activated terpolymerization was monitored by in situ FT-IR as well as differential scanning calorimetry (DSC). Moreover, the low-temperature-curing characteristics ofoHPNI-fahave also been revealed and discussed in the current study. Furthermore, the curing kinetics of theoHPNI-fawere investigated by the Kissinger and Ozawa methods. The resulting highly cross-linked thermoset based onoHPNI-fashowed excellent thermal stability as well as flame retardancy (Td10of 425 °C, THR of 4.9 KJg−1). The strategy for molecular design utilized in the current work gives a guide to the development of high-performance resins which can potentially be applied in the aerospace and electronics industries.Keywords:benzoxazine;norbornene;furan;thermosets;thermal stability
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）