JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 6
·49794
·
IF 2.52
Chuanxi Xiang,Hongxiang Chen,Wanwan Wang,Qiaoli Dai,Zhiqiang Liu,Bing Yang,Yu Zhou,Yang Zhou
Transparent self-healing polymers have a promising future, but the research on the relationship among transparency, self-healing, and structure is still challenging. The thermoplastic polyurethane elastomers containing aryl carbamate were prepared by the reaction of isocyanate-terminated prepolymer and chain-extender bisphenol A (BPA). On the one hand, the thermoplastic polyurethane elastomer could heal at a relatively low temperature due to the exchange of aryl carbamate, and exhibits 83% of healing efficiency at 90°C for 2 h. On the other hand, two methyl groups of BPA hinder the crystallization of hard segments in polyurethane, so the domain of hard segments is amorphous, while the microcrystals of soft segments dispersed in the polyurethane are affected by the content of hard segments, therefore, the transparency of polyurethane can be tailored by the content of hard segments. It provides a simple design and a feasible preparation method for transparent self-healing polymer.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Xiaohua Liu,Hongfei He,Hongliang Ding,Shaofeng Wang,Wei Zhang,Lu Liu,Yun Lei,Bin Yu
Polyurea materials are widely used in building waterproofing, heat preservation, sealing and coating due to their good mechanical properties, excellent weather resistance and strong adhesion; however, their widespread use also presents significant fire hazard risks. This study emphasizes the potential to optimize flame retardancy while preserving mechanical properties. A polyurea with a mechanical strength of 26.25 MPa and a limiting oxygen index (LOI) of 26% was developed by incorporating 20 wt% bio-chain extender and 10 wt% DOPO-based flame retardant. The cone calorimeter test demonstrated that the inclusion of 10 wt% flame retardant reduced the peak heat release rate (pHRR), total heat release (THR), and total smoke release (TSR) by 48.29%, 73.02%, and 54.32%, respectively. This work provides an effective method for improving the flame retardancy of polyurea.
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
Crystals
·
2024
·Vol. 14
·期 3
·258
·
IF 2.4
Yanjie Huang,Kanghua Chang,Jie Yao,Xueyong Guo,Chen Shen,Shi Yan
To enhance both the mechanical properties of hydroxyl-terminated polybutadiene (HTPB) binder and the combustion efficiency of aluminized propellants, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol (OFHD) was employed as a chain extender to impart mechanical regulation to the HTPB binder. Mechanical testing showed that the mechanical properties of fluoride-modified HTPB polyurethane (FPU) were significantly improved: the peak tensile strength of the optimized samples reached 1.99 MPa, and the elongation at break attained 486%. The structural characterization of the FPUs was conducted using Fourier transform infrared (FTIR) spectroscopy. Thermogravimetry-mass spectrometer (TG-MS) analysis revealed that the initial thermal decomposition temperature of the FPU shifted from 170 °C to 162 °C, accompanied by the release of fluorine-containing fragments during decomposition. Analysis of the combustion residue indicated that the addition of OFHD can reduce the agglomeration of aluminum (Al) powder in aluminized propellants. Dynamic pressure characteristics results showed an augmented pressurization rate under argon and oxygen atmospheres, increased by 18.67% and 37.29%, respectively. Heat release tests indicated that the aluminized propellants with the addition of OFHD had a higher combustion heat, being increased by 6.57%. The binder system is expected to be applied in aluminized propellants to improve the mechanical properties and combustion efficiency of Al powder.
研究领域:
推进剂化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yu-han Li,Wen-juan Guo,Wen-juan Li,Xin Liu,Hao Zhu,Jin-ping Zhang,Xing-jiang Liu,Liu-he Wei,Ai-ling Sun
It is challenging to simultaneously improve the toughness and self-healing ability of thermoplastic polyurethane (TPU) due to mutually exclusive dependence on chain motion and hard phase. In this work, a novel poly(urethane urea) (PUU) was synthesized by using 2, 6-diamimopyridine (Py) and cystamine (Cy) as chain extenders and subsequently complexed with Zn 2+ ions. It is revealed that the pyridine moieties together with formation of coordinative bonds significantly influences microphase separation by interfering with hydrogen bonding. A Py/Cy molar ratio of 1:2 is optimal to remarkably improve the toughness and self-healing ability. Specifically, its tensile strength, toughness and self-healing efficiency simultaneously improve to 9.40 ± 0.10 MPa, 64.49 ± 1.75 MJ/m 3 , and 96.64 ± 1.52% with 92%, 139% and 29% increment compared to PUU-Cy, respectively. The synergistic enhancing effect is the consequence of compromised hard phase and coordinative bonds. Firstly, decrease of hard domain content leads to loosely packed hard segments dispersing in soft phase, facilitating disulfide exchange. Secondly, the coordinative bonds serving as dynamic crosslinking joints not only restrict chain dislocation but also contribute to better self-healing ability than hydrogen bonds. An electrode film derived from embedding silver nanowires (AgNWs) into this material exhibits self-repairable and robust sensing properties due to reconstructing conducting network by self-healable matrix. This unique feature endows it with a great potential in the field of flexible electronics and wearable devices.
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
REACTIVE & FUNCTIONAL POLYMERS
·
2023
·
IF 5.1
Wei Zhang,Bingtao Wang,Yan Xia,Wei Wang,Zhenghong Guo,Zhengping Fang,Juan Li
It is a great challenge to prepare polyamide 6 (PA6) compounds with outstanding fire safety and mechanical properties. In this research, a flame retardant containing P/N/S elements (SNDP) was synthesized using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 2-thiophene-carboxaldehyde and 4-aminobenzonitrile. The PA6/SNDP compounds were prepared using a melt blending method. Two chain extenders were incorporated into PA6/SNDP compounds to adjust their mechanical properties. The results suggest that PA6 compound with 10 wt% SNDP obtains a UL-94 V-0 rating (1.6 mm) and a limiting oxygen index (LOI) value of 27.4 vol%. SNDP induces the degradation of PA6 and decreases its mechanical properties. While the two chain extenders have reinforced effects on PA6/SNDP and this effect of 1,3-phenylene-bis-oxazoline is superior to another one. Moreover, the main flame-retardant mode of actions for SNDP in PA6 is gas-phase effect, including scavenging free radicals and diluting flammable gases.
研究领域:
材料科学
·
防火安全工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 3
·510
·
IF 4.967
Wen-Jun Wu,Xiao-Li Sun,Qinghua Chen,Qingrong Qian
Annual production of textile fibers is continuing to rise and the substantial discharge of undegradable waste polyester fibers can cause serious environmental and even health problems. Thus, the recycling and reuse of recycled poly(ethylene terephthalate) from waste textiles (rPET-F) is highly desirable but still challenging. Here, five chain extenders with a different number of epoxy groups per molecules were used to blend with discarded PET fibers and improve its viscosity and quality loss in the recycling process. The molecule weight, thermal properties, rheological properties and macromolecular architecture of modified r-PET were investigated. It was found that all modified rPET-F samples show higher viscosities and better thermal properties. rPET-F modified by difunctional EXOP molecules show linear structure and improved rheological properties. rPET-F modified by polyfunctional commercial ADR and synthesized copolymers exhibit a long chain branched structure and better crystallization. This study reveals a deeper understanding of the chain extension and opens an avenue for the recycling of PET textiles.Keywords:waste textile;PET fibers;chain extender;mechanical recycling;rheological property
研究领域:
材料科学
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环境科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Xiaowen Yan,Ruoyu Zhang,Chunjun Zhao,Lijing Han,Shuai Han
With the development of self-healing materials and the increasing demands from complicated application environment, underwater self-healing is attracting more and more attention. However, until now, the effects of different dynamic chain extender and water molecular on the self-healing of polyurethanes have not been investigated yet. In this work, we synthesized two types of polyurethanes with 2,4-pentanedione dioxime (DMG) and bis(4-hydroxyphenyl) disulfide (HPS) as the chain extenders, respectively. Furthermore, PDMS was adopt as the soft segment and isophorone diisocyanate (IPDI) was used the hard segment. It is found that they all have good flexibility, probably due to the low Tg of PDMS soft segment. Interestingly, the five samples own a similar Tg at ∼ -112 °C, which belongs to PDMS. Due to the hydrophilicity of the majority component of PDMS, the five polyurethanes have water contact angle larger than 90°. Nevertheless, the water absorption experiment clearly show that they can absorb water until saturation. The self-healing experiments were carried out in both air and water, which proved that the underwater self-healing speed of DMG polyurethanes was increased significantly. It is deduced that the water could plasticize these hydrophobic polymers and accelerate the self-healing speed underwater.
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
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Shang Ke Yang,Yan Xiao Mu,De Li,Tong Li,Hai Lan Lin,Ai Ping Zhang,Jun Bian,Dai Qiang Chen,Ke Cheng Yang
Developing biobased thermoplastic polyurethane (TPU) from renewable biomass resources is becoming urgent due to resource scarcity and environmental protection requirements. Herein, a chain extender diol (VAN–OH) containing dynamic imine bonds was synthesized using renewable biomass resource vanillin (VAN), then combined with 1,4-butanediol (BDO) in various proportions, and reacted with poly(caprolactone diol) and 4,4′-diphenylmethane diisocyanate to synthesize degradable biobased TPU (BTPUs) with excellent performance. Fourier transform infrared, 1H NMR, X-ray diffraction, DMA, thermogravimetric analysis, molecular weight, chemical degradation, and mechanical tests systematically investigated the relationships between the polymer chain structure and the performance of BTPUs. The experimental results demonstrated that the high regularity and strong polar bonds (imine and ether) of VAN–OH enhanced the interactions between macromolecular chains and improved the hydrogen bonding combination, crystallinity, and phase separation of BTPUs, thereby exerting significant contributions to their thermomechanical and degradable properties. BVTPU1 with a mole ratio of BDO/VAN–OH = 7.5:2.5 exhibited the best mechanical performance, degradation time was 37.5% shorter, and initial pyrolysis temperature increased by 13.8% compared to BTPU0 without VAN–OH. In addition, BTPUs have shown some biodegradability and environmental friendliness in soil burial experiments under natural conditions.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Cheng Zhang,Hongyi Qi,Tianxiao Chang,Yahe Wu,Jiacheng Cao,Mingsen Chen,Yanbin Huang,Wantai Yang
Maleic anhydride (MAH) copolymers have a wide range of applications in various fields. However, the difficulty in obtaining high-molecular-weight (Mw) copolymers through polymerization often limits their potential for application expansion. In this paper, diols were chosen as chain extenders to increase the Mw of MAH copolymers through esterification reactions between anhydride and alcohol, achieving the goal of “chain extension”. As the reaction progressed, the double-end esterification content (DEC) increased and the Mw showed exponential growth accompanied by an increase in gel content. The effects of various reaction parameters, including the temperature, reaction time, types and amounts of diols, polymer concentration, and Mw of raw polymer, on the Mw and gel content of the product were investigated systematically. Furthermore, this method can effectively increase the Mw of various mixed olefin–MAH copolymers. The experimental results demonstrated that the Mw of raw polymers could be increased by up to 70 times (from 18.0 to 1270.8 kg/mol), thereby broadening the polymers’ potential applications.
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 APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 44
·
IF 1.768
Teng Wang,Zhihua Zhang,Ran Song,Xinlin Tuo,Jigong Wu
Iodinated polyurethanes (IPUs) with radiopaque property were prepared using poly(oxytetramethylene) glycol, 4,4′-diphenylmethane diisocyanate, and a novel chain extender. The chain extender, described as N-(1,3-dihydroxypropan-2-yl)-2,3,5-triiodobenzamide, was synthesized in two steps from 2-aminopropane-1,3-diol and 2,3,5-triiodobenzoic acid with a high yield. A thorough study on the chemical structure, mechanical properties, radiopacity, and physiological properties of the IPUs was conducted. It is revealed that with increasing content of chain extender, the molecular weights of IPUs decreased slightly while the tensile modulus and breaking strength of IPUs increased significantly, illustrating an excellent comprehensive performance. With iodine content high to about 16 wt %, the IPU sample is equal to the aluminum plate with the same thickness in X-ray radiopacity, meaning that the synthesized polyurethanes are promising as radiopaque materials. The oxidative degradation and cytotoxicity tests illustrated a good performance of stability and biocompatibility for the IPUs. It confirmed that the as-synthesized IPUs are promising for biomedicine applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42693.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2023
·
IF 3.4
Weihua Ye,Yanchao Yuan,Shumei Liu,Jianqing Zhao
The chain extension of polyamide 6 (PA6) via a chemical reaction between a chain extender and the amino and carboxyl groups of the polymer increases the molecular weight and improves the mechanical properties, while typically deteriorates PA6 processability owing to cross-linking. To resolve this issue, a dynamic covalent chain extender containing two anhydride groups is synthesized, which reacts only with amino groups, and employed to connect the PA6 molecular chains via the reaction between anhydride groups and terminal amino groups of PA6. On adding 3 wt% of the chain extender, the content of amino end groups is decreased from 30.6 to 5.8 μmol g −1 and the yield strength and elastic modulus of chain-extended PA6 exceed those of original PA6 by 15.8% and 23.4%, respectively; meanwhile, the melt torque of chain-extended PA6 is lower by 35.0% approximately, and the complex viscosity is also decreased. As far as we know, the dynamic covalent chain extender is used for the first time in the chain extension of PA6. This study provides a prospective approach to recycle PA6 for simultaneously improving mechanical properties and processability.
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 POLYMER SCIENCE
·
2023
·Vol. 61
·期 15
·1572-1583
·
IF 3.4
Bo Li,Juan Li,Shaowen Huang,Shuhao Qin,Nan Liu
Polylactic acid (PLA) packaging materials are useful, safe, and degradable in the natural environment, and hence, have attracted considerable interest. In particular, the barrier properties of PLA are the focus of current research. In this study, organic montmorillonite (OMMT) modified with an epoxy chain extender (CE) was prepared as a barrier functional additive for PLA and PLA alloy materials. The effects of the CE-OMMT on the properties of PLA and PLA/PHA (polyhydroxyalkanoates) composites were investigated. The CE-OMMT was characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and thermogravimetry (TG). The results showed that the CE-OMMT was successfully synthesized, and that the addition of the CE did not change the crystal structure of OMMT. The morphology and microstructure of the PLA/CE-OMMT and PLA/PHA/CE-OMMT composites were characterized using XRD and transmission electron microscopy (TEM). The dispersion of the CE-OMMT in the PLA and PLA/PHA composite films was significantly enhanced. XRD analysis showed that OMMT intercalated well into the matrix. The rheological, barrier, and mechanical properties of the PLA nanocomposite films were systematically studied. The results showed that the CE-OMMT enhanced the mechanical and barrier properties of the composite films. Compared with neat PLA, the elongation at break of the PLA/CE-OMMT and PLA/PHA/CE-OMMT composite films with the addition of 3% CE-OMMT increased by 449% and 788.4%, the oxygen permeability decreased by 57.74% and 59%, and the water vapor permeability decreased by 44.79% and 53.25%, respectively. Therefore, the modified PLA composite film is a promising substitute for packaging applications. Graphical
研究领域:
材料科学
·
包装工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）