乙丙共聚物及其共混物晶型探讨

A STUDY ON α-γ TRANSFORMATION OF ETHYLENE-PROPYLENE COPOLYMERS AND MIXTURES

用广角X-射线衍射(WAXD)和偏光显微镜(PLM)方法,研究了具有乙丙长序列乙丙共聚物及其共混物,发现通过熔融慢冷结晶样品,C_3含量在30mol％以上,衍射角2θ=20°处出现了属于γ-PP晶型的(140),(130)晶面衍射。含有乙丙长序列链结构的乙丙共聚物及共混物属(α+γ)混晶结构;含乙丙长序列的EPR以γ-相为主,嵌段物和共混物则以α-PP为主,形成γ-PP结构的必要条件是含有乙丙长序列链结构样品熔融慢冷结晶。

Ethylene (E)-Propylene (P) copolymers and mixtures with long E-P sequence structures were investigated using WAXD and PLM methods. As the content of Cs reached more than 30 mol %, the (140), (130) crystal planes appear at 29 = 20 in X-ray diffraction patterns of me-Itcrystallized samples. Planes of (140), (130) are the characteristics of γ-form, which originate from (a +γ) form in E-P copolymers.γ-form is mainly observed for long E-P sequence copolymers as slow cooling, but a-form is mainly for blocks and mixtures.