Polymers
·
2022
·Vol. 14
·期 10
·2039
·
IF 4.967
Ziyun Shen,Liuchun Zheng,Danqing Song,Yi Liu,Chuncheng Li,Jiajian Liu,Yaonan Xiao,Shaohua Wu,Tianbo Zhou,Bo Zhang,Xuedong Lv,Qiyong Mei
A series of non-isocyanate poly(ether urethane) (PEU) were prepared by an environmentally friendly route based on dimethyl carbonate, diols and a polyether. The effect of the chemical structure of polyurethane hard segments on the properties of this kind of PEU was systematically investigated in this work. Polyurethane hard segments with different structures were first prepared from hexamethylene di-carbamate (BHC) and different diols (butanediol, hexanediol, octanediol and decanediol). Subsequently, a series of non-isocyanate PEU were obtained by polycondensation of the polyurethane hard segments with the polyether soft segments (PTMG2000). The PEU were characterized by GPC, FT-IR,1H NMR, DSC, WAXD, SAXS, AFM and tensile testing. The results show that the urea groups generated by the side reaction affect the degree of crystallization of hard segments by influencing the hydrogen bonding of the hard segments molecular chains. The degree of hard segment crystallization, in turn, affects the thermal and mechanical properties of the polymer. The urea group content is related to the carbon chain length of the diol used for the synthesis of hard segments. When butanediol is applied to synthesize hard segment, the hard segment of the resulting PEU is unable to crystallize. Therefore, the tensile strength and modulus of elasticity of butanediol-based PEU is lowest among three, though it possesses the highest urea group content. When longer octanediol or decanediol is applied to synthesize the hard segment, the hard segments in the resulting polyether-based polyurethane are crystallizable and the resulting PEU possesses higher tensile strength.Keywords:non-isocyanate;poly(ether urethane);hard segment
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
CHINESE JOURNAL OF POLYMER SCIENCE
·
2016
·Vol. 34
·期 9
·1070-1078
·
IF 1.811
Feng Li-dong,Xiang Sheng,Sun Bin,Liu Yan-long,Sun Zhi-qiang,Bian Xin-chao,Li Gao,Chen Xue-si
Poly(ether urethane)s (PEU), including PEUI15 and PEUH15, were prepared through chain-extension reaction of poly(ethylene glycol) (PEG-1500) using diisocyanate as a chain extender, including isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). These PEUs were used to toughen polylactide (PLA) by physical and reactive blending. Thermal, morphological, mechanical and aging properties of the blends were investigated in detail. These PEUs were partially compatible with PLA. The elongation at break of the reactive blends in the presence of triphenyl phosphate (TPP) for PLA with PEUH15 or PEUI15 was much higher than that of the physical blends. The aging test was carried out at -20 °C for 50 h in order to accelerate the crystallization of PEUs. The PEUs in the PLA/PEU blends produced crystallization and formed new phase separation with PLA, resulting in the declined toughness of blends. Fortunately, under the aging condition, although PEUH15 in blends could also form crystallization, the reactive blend of PLA/PEUH15/TPP(80/20/2) had higher toughness than the other blends. The elongation at break of PLA/PEUH15/TPP(80/20/2) dropped to 287% for the aging blend from 350% for the original blend. The tensile strength and modulus of PLA/PEUH15/TPP blend did not change obviously because of the crystallization of PEUH15.
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
·
2019
·
IF 3.771
Ziyun Shen,Liuchun Zheng,Chuncheng Li,Guoming Liu,Yaonan Xiao,Shaohua Wu,Jiajian Liu,Bo Zhang
DMC-derived poly (ether urethanes) were prepared via isocyanate-free route. The transurethanization reaction of the non-isocyanate route needs higher temperature as compared with the traditional route. There may be some unknown side reactions under high temperature which lead to changes in chemical structure and subsequent thermal and mechanical properties of the novel DMC-derived non-isocyanate polyurethanes (NIPUs). Two 1,6-hexamethylene diisocyanate based polyurethanes (HDIPUs) were prepared as a control. HDIPUs possessed a higher melting point and better mechanical properties than NIPUs. In order to find out the causes of the difference in their thermal and mechanical properties, the structure, crystallization behavior , morphology and microphase separation behavior of NIPUs and HDIPUs were systematically studied and compared in this work. It was found that the structural distinction between NIPUs and HDIPUs was originated from the hard segments. The urea content in the hard segments of NIPUs was much higher than that of HDIPUs. The formation of urea groups was explained by the side reactions during the transurethanization process of NIPUs. Due to the random insertion of urea groups on the hard segments of NIPU, the strength of hydrogen bonding between hard segments and the crystallinity of the hard phase were lower than those of HDIPU. Therefore, the compatibility between the hard phase and the soft phase of NIPU was increased, resulting in poor thermal and mechanical properties.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2013
·Vol. 214
·期 7
·824-834
·
IF 2.386
Lidong Feng,Xinchao Bian,Yi Cui,Zhiming Chen,Gao Li,Xuesi Chen
Poly( L -lactide) (PLLA) is melt blended with poly(ether urethane) (PEU) based on poly(ethylene glycol) blocks via a chain-extension reaction by diisocyanate as a chain extender to improve its flexibility without sacrificing comprehensive performance. The elongation at break of the blends with triphenyl phosphate (TPP) as a reactive blending additive is much higher than that without TPP by physical blending. When 10 wt% PEU is blended, the former elongation reaches to 298%, while the latter one is only approximately 20%. The reactive blending forms a PLLA–PEU block copolymer, thus improving their compatibility. When the weight-average molecular weight ( M w ) of PEUs is 18–90 kg mol −1 , the effect of M w is very little on tensile properties of blends. The rheological properties of the blends are modified through the content and molecular weight of PEU. The complex viscosity ( η *) of PLLA/PEU blends increases with increasing M w of PEU. The η * of the PLLA blend containing 5 wt% PEU in M w 73 kg mol −1 is higher than that of neat PLLA. The water absorption of the PLLA/PEU blends enhances because of the hydrophilicity of PEUs versus neat PLLA.
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
危险品化学品经营许可证（带存储）