摘要
以聚环氧丙烷二醇(PPG)、MDI,均苯四酸二酐(PMDA)为单体,首次合成了不同硬段长度的醚氨酯-酰亚胺嵌段共聚物(PUI),红外光谱证实了聚酰亚胺硬段的存在。PUI的特性粘数(32℃,DMAc)[η]为0.34～1.20dL/g。TG及DTG分析表明,PUI的热分解温度(N_2)为344～348℃,而以丁二醇为扩链剂的同类PU为323℃。 研究了PUI及PU的应力-应变行为,二者皆属典型的弹性体。PUI比PU具有更高的弹性模量及抗张强度,在相同硬段含量时,PUI的抗张强度为35.1MPa,而PU仅为10.8MPa。PUI的形变行为与典型的交联橡胶不一致。在拉伸比λ<1.8时服从Guth统计理论σ=G(λ-λ^(-2));在大形变区服从Mooney-Rivlin应变能函数式σ=(λ-λ^(-2))(2C_1+2C_2/入),2C_2的数值与硬段含量无关,正象交联橡胶的2C_2与硫化程度无关一样,因而硬段含量与硫化程度有相当的含义。
Ether based uretuane/imide multi-block copolymers (PUI) were synthesized by PPG,MDI and PMDA for the first time. IR spectra proved the formation of PI rigid segments. The intrinsic viscosity [η] =0.34-1.20dL/g, TG and DTG analysis indicated that decomposition temperation Td of PUI are 344-348℃, while the Td of PU extended by butanediol (BD) is 323℃.Stress-strain behavior of PUI and PU samples were studied. Both of them belong to the typical of elastomer. PUI samples have much greater elastic modulus and tensile strength than PU. In the same rigid segment content, the value of tensile strength for PUI and PU are 35.1MPa and 10.8MPa, respectively. Extension behavior of PUI samples are similar to the classical vulcanizate. In the region of small deformation (extension ratio λ<1.8),σ-ε behavior consist with Guth's statistical theory of rubber networks, that isσ = G(λ-λ-2), In the region of large deformation (λ = 1.8-4.0) , Mooney-Rivlin equ. σ=(λ-λ-2) (2C1 + 2C2/λ) can describe the σ-εbehavior perfectly. Plots of σ/λ -λ-2vs.1/A do be linear with a slope of 2C2.It was interestingly found that 2C2 of various PUIs remain constant and ate independent of hard-segment content, just as the 2C2 for crosslinked rubber are independent of their vulcanization degree.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
1989年第3期45-45,共1页
Polymer Materials Science & Engineering
