等规聚丙烯／二元乙丙橡胶合金相分离对结晶动力学的影响  

STUDY ON LIQUID-LIQUID PHASE-SEPARATION AND ITS EFFECT ON THE CRYSTALLIZATION KINETICS OF BLENDS COMPOSED OF ISOTACTIC POLYPROPYLENE/ETHYLENE-PROPYLENE RUBBER

作　　者：陶礼阳[1] 上官勇刚[1] 姜贤[1] 郑强[1] 

机构地区：[1]浙江大学高分子科学与工程学系高分子合成与功能构造教育部重点实验室,杭州310027

出　　处：《高分子学报》2008年第1期48-54,共7页Acta Polymerica Sinica

基　　金：国家基础研究专项经费(项目号2005CB623800);国家自然科学基金(基金号50603023);高等学校博士学科点专项科研基金(基金号20040335077)资助项目

摘　　要：用小角激光光散射(SALLS)、相差显微镜(PCM)、示差扫描量热仪(DSC)和偏光显微镜(POM)研究了聚丙烯/二元乙丙橡胶(iPP/EPR)共混体系的相分离行为和等温结晶行为.发现iPP/EPR(50/50,W/W)发生的液-液相分离遵循spinodal机理.通过Cahn-Hilliard方程求得了不同实验温度下iPP/EPR的表观扩散系数(Dapp)以及spinodal温度(Ts).考察了不同相分离程度的iPP/EPR体系结晶动力学,发现延长相分离时间(tps)或提高相分离温度(Tps)均会导致半结晶时间(t1/2)增大,即结晶速率降低.这被归于EPR成核作用的降低.动力学分析结果表明Avrami模型适用于描述该体系的等温结晶过程,其结晶机理基本不受相分离程度的影响,结晶均以瞬时成核和三维生长为主.The liquid-liquid phase-separation （LLPS） and isothermal crystallization behavior of isotactic polypropylene/ethylene-propylene rubber blend （iPP/EPR） were investigated by using small angle laser light scattering （ SALLS ）, differential scanning calorimetry （ DSC ）, phase contrast microscopy （ PCM ） and polarized optical microscopy （POM）. Results reveal that LLPS of （50/50, W/W） iPP/EPR blend happens at temperaturesabove the melting point of iPP,and its kinetics follows the spinodal decomposition （SD） mechanism. The apparent diffusion coefficient （Dapp） and the spinodal temperature （ Ts ） of the iPP/EPR samples were calculated on the basis of the Cabn-Hilliard theory. Moreover, it is found that the Dapp increases with the increase of temperature, representing the LCST behavior of iPP/EPR. The development of phase morphologies could be obtained byquenching in liquid N2 hand,the structure of i continuous phases form, the IPP/EPR samples subjected to annealing with different ti PP/EPR melt appears nearly homogenous at the beginning of and the phase connectivity grows until macroscopic spherical me at 200℃. On the Other LLPS. Furthermore, the cotexture generates. Both theincreases of phase separation time （tps） and phase separation temperature （Tps） result in the decrease of the crystallization rate. The kinetic results indicate that the Avrami model is qualified for describing the isothermal crystallization of iPP/EPR. It is believed that the degree of phase-separation has little effect on the crystallization kinetics and the crystallization gives priority to instantaneous nucleation and three-dimension-growth.

关 键 词：等规聚丙烯/二元乙丙橡胶合金 相分离 相形态 等温结晶 

分 类 号：TQ330[化学工程—橡胶工业]