Polymers
·
2020
·Vol. 12
·期 10
·2407
·
IF 3.426
Mingjun Niu,Zhongzhou Zhang,Zizhen Wei,Wanjie Wang
Poly(lactic) acid (PLA) is one of the most promising biobased materials, but its inherent flammability limits its applications. A novel flame retardant hexa-(DOPO-hydroxymethylphenoxy-dihydroxybiphenyl)-cyclotriphosphazene (HABP-DOPO) for PLA was prepared by bonding 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide (DOPO) to cyclotriphosphazene. The morphologies, mechanical properties, thermal stability and burning behaviors of PLA/HABP-DOPO blends were investigated using a scanning electron microscope (SEM), a universal mechanical testing machine, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), limiting oxygen index (LOI), vertical burning (UL-94) and a cone calorimeter test (CCT). The LOI value reached 28.5% and UL-94 could pass V-0 for the PLA blend containing 25 wt% HABP-DOPO. A significant improvement in fire retardant performance was observed for PLA/HABP-DOPO blends. PLA/HABP-DOPO blends exhibited balanced mechanical properties. The flame retardant mechanism of PLA/HABP-DOPO blends was evaluated.Keywords:flame retardant;poly(lactic acid);mechanical properties;blends
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 10
·4091
·
IF 4.6
Jia-Yao Chen,Xue-Wen Zhang,Tian-Yu Wu,Hai-Mu Ye
Crystalline/crystalline blends of polymer have shown advantages in the preparation of new polymeric materials. However, the regulation of co-crystallization in a blend is still full of challenges due to the preferential self-crystallization driven by thermodynamics. Here, an inclusion complex approach is proposed to facilitate the co-crystallization between crystalline polymers, because the crystallization process displays a prominent kinetics advantage when polymer chains are released from the inclusion complex. Poly(butylene succinate) (PBS), poly(butylene adipate) (PBA) and urea are chosen to form co-inclusion complexes, where PBS and PBA chains play as isolated guest molecules and urea molecules construct the host channel framework. The coalesced PBS/PBA blends are obtained by fast removing the urea framework and systematically investigated by differential scanning calorimetry, X-ray diffraction, proton nuclear magnetic resonance and Fourier transformation infrared spectrometry. It is demonstrated that PBA chains are co-crystallized into PBS extended-chain crystals in the coalesced blends, while such a phenomenon has not been detected in simply co-solution-blended samples. Though PBA chains could not be totally accommodated in the PBS extended-chain crystals, their co-crystallized content increases with the initial feeding ratio of PBA. Consequently, the melting point of the PBS extended-chain crystal gradually declines from 134.3 °C to 124.2 °C with an increasing PBA content. The PBA chains playing as defects mainly induce lattice expansion along thea-axis. In addition, when the co-crystals are soaked in tetrahydrofuran, some of the PBA chains are extracted out, leading to damage to the correlative PBS extended-chain crystals. This study shows that co-inclusion complexation with small molecules could be an effective way to promote co-crystallization behavior in polymer blends.Keywords:co-crystal;polyester;blend;inclusion complex;thermal property
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 20
·7086
·
IF 4.927
Xue-Wei Wei,Cong Chen,Tian-Yu Wu,Li-Hai Cai,Hai-Mu Ye
Co-crystallization plays a crucial role in the integration and regulation of thermal and mechanical properties in polymer blends, but the poor compatibility of the components in the crystal phase has always been a major obstacle to co-crystallization, which puts forward stricter requests for linkage and interaction between different entities. On the basis of the hydrogen-bonding interaction that can promote chain stacking and thus improve miscibility, we propose that crystalline/crystalline blends of 2-ureido-4[1H]-pyrimidinone (UPy)-functionalized poly(butylene succinate) and poly(butylene fumarate) (PBS-UPy/PBF-UPy) where UPy groups with quadruple hydrogen-bonding interaction are employed to connect different chain ends, could inhibit phase separation and improve co-crystallization. PBS-UPy/PBF-UPy blends exhibit complex component-dependent and cooling-rate-dependent co-crystallization behavior. A high level of co-crystallization occurs in the range of PBS-UPy-rich fractions, and the proportion could approach over 98% under optimized conditions with the aid of UPy quadruple hydrogen bonds interaction. This work enriches the understanding of co-crystallization in crystalline/crystalline polymer blends and provides more possibility for the design of structures and properties of polymer materials.Keywords:co-crystallization;polymer blend;hydrogen bond;compatibility
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 5
·
IF 1.866
Yijian Wu,Baoqing Shentu,Zhixue Weng
The SEBS/PP thermoplastic vulcanizates (TPVs) were prepared by melt blending. Di- tert -butyl peroxide (DTBP) was used as the curing agent in combination with trimethylopropane trimethacrylate (TMPTMA) and poly(styrene- b -butadiene-bstyrene) (SBS) as the coagents for the curing process. The synergistic effect of TMPTMA and SBS on the structure and properties of TPVs was studied by means of FT-IR, DSC, torque rheometer, and universal testing machine. Both SEBS and PP crosslinked and the network structure formed under the participation of TMPTMA and SBS. Compared with the sole addition of the coagent, simultaneous loading of both TMPTMA and SBS could provide the TPVs with better solvent-resistance and excellent mechanical properties. The crosslinking mechanism of the TPVs was also proposed. The slight lower value of T m for the TPVs indicated the improved miscibility between PP and SEBS due to the crosslinking reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44392.
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
MACROMOLECULES
·
2017
·
IF 5.835
Dongdong Zhou,Shaoyong Huang,Jingru Sun,Xinchao Bian,Gao Li,Xuesi Chen
The crystallization behaviors and microstructures of poly(l-2-hydroxyl-3-methylbutanoic acid)/poly(l-lactide) blends [P(L-2H3MB)/PLLA] were investigated by OM, DSC, SAXS, in situ temperature-dependent WAXD, and in situ synchrotron WAXS. The blends exhibited a homogeneous state at 250 °C. In the cooling process, P(L-2H3MB), with higher melting temperature, crystallized first at 166.7 °C and drove the formation of the phase separation and microstructure. And the amorphous P(L-2H3MB) and PLLA were excluded into the interlamellar and interfibrillar regions of the former P(L-2H3MB) crystallites. For P(L-2H3MB)/PLLA (5/5), the amorphous P(L-2H3MB) in the interfibrillar regions continued to form crystallites sequentially at 134.6 °C, which clearly confirmed the fractional crystallization of P(L-2H3MB). In our knowledge, this unique fractional crystallization has not been reported yet, of the component in miscible blend, which crystallized first under little confinement. This work provided a new viewpoint and understanding of the relationship between fractional crystallization and microstructures in crystalline/crystalline blends.
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
Polymer-Plastics Technology and Materials
·
2020
·
IF 0
Yang Pan,Guangfeng Wu,Huifang Ma,Shujie Zhou,Huixuan Zhang
Herein, graft-modified ethylene-1-octene copolymer (POE-g-GMA) and styrene-butadiene-styrene triblock copolymer (SBS-g-GMA) were found to be excellent reactive compatibilizers for immiscible poly(ethylene terephthalate) (PET)/high-density polyethylene (HDPE) blends via in-situ reaction compatibilization. With increase in compatibilizer amount, uniform phase morphology was observed in all the blends. Thus, exhibiting enhanced mechanical properties, especially, the notched Izod impact strength. In comparison with SBS-g-GMA, compatibilizer POE-g-GMA demonstrated greater impact on the compatibility. The addition of 15% POE-g-GMA produced blends with best mechanical properties. Besides, both POE-g-GMA and SBS-g-GMA enhanced the melt viscosity of PET/HDPE blends.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
产品关联
DOI
POLYMER ENGINEERING AND SCIENCE
·
2024
·Vol. 64
·期 7
·2988-3002
·
IF 3.2
Sun Yun,Xuefeng Pan,Feng Zhang,Xuelian He
The cavitation process of high-performance HDPE/UHMWPE blends with a uniform dispersion of UHMWPE during cold stretching was investigated. It was observed that incorporating a small amount of UHMWPE into the HDPE matrix resin can serve as a nucleating agent, increasing the number of contact sites and accelerating the crystallization rate. This leads to the formation of thicker lamellar crystals and tethered molecules, ultimately enhancing the mechanical properties of the HDPE matrix. Furthermore, the relationship between the natural tensile ratio and strain-hardening modulus was confirmed. Microstructural changes within the blends were also explored. As the drawing tangles in the middle, the cavities subsequently evolve by collapsing and merging to align parallel to the tensile direction, culminating in tensile damage forming a large crack in the final macroscopic form. As a result, the presence of more tethered molecules in the later stages of stretching inhibits further cavity growth. Highlights The HDPE/UHMWPE blends were prepared by solution blending and ultrasound-assisted twin-screw extrusion. The mechanisms underlying the formation and evolution of cavities in HDPE/UHMWPE blends, which lead to stress whitening during tensile damage, were examined by using DSC and SAXS/WAXD. The relationship between microstructure and mechanical properties was analyzed by cold-drawing the molded blended sheets at room temperature.
研究领域:
材料科学
·
高分子物理
✓ 已验证
产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2013
·Vol. 291
·期 7
·1573-1580
·
IF 2.161
Zhao Xuejuan,Zhang Jun,Chen Shuangjun,Wang Xiaolin,Wang Jianxin
The in situ polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) in poly(vinylidene fluoride) (PVDF) solution was carried out to prepare hydrophilic PVDF/PPEGMA blends. Based on T
g data, the system displayed some miscibility at low PPEGMA content because there were some interactions between PVDF and PPEGMA, as illustrated by Fourier transform infrared spectroscopy analysis, while the miscibility disappeared at high PPEGMA content. The β phase was the predominant crystalline phase of PVDF in the in situ blends, which was independent on PPEGMA content. However, the addition of PPEGMA could change the unit cell structure in the direction of the a -axis of β phase. The degree of crystallinity of the in situ blends calculated by wide-angle X-ray diffraction and differential scanning calorimetry displayed different tendencies with PPEGMA content. The scanning electron microscopy showed that the “spherulites” size increased with the increase in PPEGMA content, since the “spherulites” were comprised of not only crystalline PVDF but also amorphous PVDF and PPEGMA. In addition, the in situ blend had a great improvement in the hydrophilicity; specifically, its water contact angle was down to 26° when the PPEGMA content only increased to 26.9 wt.%.
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
COMPOSITES SCIENCE AND TECHNOLOGY
·
2022
·
IF 9.879
Liangjun Li,Hangbo Yue,Qiqi Wu,Juan P. Fernández-Blázquez,Peter S. Shuttleworth,James H. Clark,Jianwei Guo
Cottonseed protein (CP) was compounded with polycaprolactone (PCL) in different concentrations by melt blending , and then hot-pressed to prepare CP/PCL blend films. A co-continuous phase is formed when the CP/PCL content is 50/50, and the tensile strength , modulus and toughness are 9, 10, and 63 times greater than that of neat CP film . This remarkable improvement is mainly due to the intrinsic flexibility of long PCL polymer chains, whilst the polymeric crystalline structure can still be formed. Furthermore, 1 wt% of compatibilizing agent — glycidyl methacrylate (GMA) or maleic anhydride (MA), is added to the blends. Measurements from scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) showed the presence of chemically reactive compatibilization between the compatibilizer and CP or PCL phase, and the two phases with strong binding forces are well dispersed. Meanwhile, the compatibilizer can induce the protein secondary structure to unfold, further increasing the physical compatibilization between the protein and polymer chains, which has a noticeable contribution to the blend's mechanical, hydrophobic properties and thermal stability. This work adds new element to the knowledge of compatibilization in terms of optimised interfaces of polymer blends , and provide new insights into fabricating high performance protein derived bioplastics and biocomposites .
研究领域:
材料科学
·
生物材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yihui Xu,Yudong Liu,Ling Liu,Jun Liu
The blending of different elastomers can greatly broaden the application range of rubber materials. However, due to the poor compatibility between polar elastomers and non-polar elastomers, severe phase separation occurs during the blending process, which severely degrades their processing performance and mechanical properties. In this paper, we prepared SBR-P/XNBR blends by emulsion blending polar modified styrene-butadiene rubber (SBR-P) latex with carboxylated nitrile rubber (XNBR) latex. The effects of the blending ratios on the vulcanization behavior, mechanical strength, dynamic mechanical properties, and oil resistance of the rubber compounds were studied. Experimental results showed that the mechanical strength and oil resistance of the modified SBR-P/XNBR blends are significantly higher than the unmodified SBR and XNBR blends. The dynamic mechanical analysis curve results of the rubber compounds showed that SBR-P has good compatibility with XNBR. With the increasing addition of XNBR, the oil resistance of the rubber compounds improves, and the solvent adsorption is reduced by over 60%.This study proposes a solution for utilizing non-polar rubbers, which are typically not oil-resistant, in oily environments. The proposed solution enables the preparation of composites with excellent mechanical properties in such environments.
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 POLYMER RESEARCH
·
2015
·Vol. 22
·期 2
·1-14
·
IF 1.92
Li Hongbin,Shi Wenying,Zhang Yufeng,Zhou Rong
Poly( p -phenylene terephtalamide) (PPTA) reinforcing blends are of great scientific interest, however the thermodynamic difference of the components make them incompatible with inferior physical-chemical properties. In this work, with the aim of exploring novel separation membrane materials, PPTA/poly(vinylidene fluoride) (PVDF) reinforcing blends were prepared by a novel reactive blending technique of in situ polymerization (method І), and the conventional solution blending (method Π), respectively. The effects of these two methods on polymers compatibility were investigated and compared through ATR-FTIR, XRD, XPS and FESEM characterization. Thermal stability, surface hydrophilicity and mechanical properties were measured through TG, water contact angle (WCA) and tensile measurements. It was found that stronger intermolecular interaction especially hydrogen bonds between polymer components in in-situ blends prevented PVDF from crystallization and a continuous phase configuration appeared. However, slution blends showed an obvious two-phase structure in FESEM observation which varied from a spherical crystallization of PVDF at low PPTA content to a fibrous-like crystallization of PPTA at high PPTA concentration. Solution blends showed lower hydrophilicity which was attributed to the PPTA crystallization and its perpendicular uniplanar orientation along blend film surface. In-situ blends exhibited higher tensile strength which was due to the better polymers compatibility between the rigid reinforced PPTA molecules and flexible PVDF matrix. The PPTA/PVDF in-situ blend is a promising candidate for the high-performance separation membrane material.
研究领域:
材料科学
·
高分子化学
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2017
·
IF 2.464
Jianxi Huang,Haijun Yang,Min Chen,Te Ji,Zhengchi Hou,Minghong Wu
Systematic study of FTIR spectra was carried out on the PES/PVP blends and PES-g-PVP copolymers . In the blends, no shift of carbonyl group absorbance was observed. In the copolymers, there was an occurrence of blue-shift that increases with the grafting degree, which can be used as a compelling evidence of PVP being grafted onto PES . This phenomenon was interpreted from the stereo-hindrance effect. Besides, as the intensity of carbonyl group absorbance increased proportionally with the degree of grafting obtained by elementary analysis, FTIR, a simple and easy tool, became feasible for the quantitative determination of PVP content in the graft copolymers . Calibration curves with high correlation coefficient were established from which the quantitative relationship between the intensity of carbonyl group absorbance normalized by a chosen internal reference and the grafting degree can be obtained.
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
危险品化学品经营许可证（带存储）