【摘要】 用DSC研究了PP,PP g VAc和两种不同醇解率PP g VOH的非等温结晶行为,以Reziorny修正的Avrami方程进行了动力学分析,用偏光显微镜观察了接枝物球晶形态的变化。研究结果表明:VOH接枝链可以有效地促进PP异相成核,导致Avrami指数n随醇解率增加而降低,结晶温度显著增加,结晶热焓增加;同时,由于VOH引入支链,降低了分子链的规整性,限制了PP排入晶格的速率,致使半结晶时间t1/2和结晶速率Zc常数降低。试样的偏光显微镜观察表明,PP g VAc的醇解率增加,球晶数目增多,直径减小,完善程度降低。更多还原

【Abstract】 The crystallization behaviors of PP, PP-g-VAc and PP-g-VOH with different saponification percentages (P_S) were studied by the differential scanning calorimetry (DSC) and the crystallization kinetics under non-isothermal conditions were analyzed by Jeziorny method. The morphologies of spherulite of the samples were inspected by a polarizing microscope. The results showed the grafting of VOH could accelerating the nucleation rate of PP effectively, which led to decrease in Avrami exponent n and increase in crystallization temperature T_c and enthalpy ΔH. Simultaneously, because the macromolecular regularity was decreased, the crystallization half time t_ 1/2 and crystallization rate constant Z_c of PP-g-VOH were decreased. Micrographs of the crystal showed the number of spherulite increased markedly, but the diameter and integrity of crystal decreased with the increase in P_S.更多还原