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用DSC、WAXD和SAXS研究了聚乙烯醇(PVAl)/聚乙烯基吡咯烷酮(PVP)共混体系的结晶行为.PVAl的结晶度随PVP含量增加而减少,并存在结晶度为零的组成(PVAl)的重量分数约为50％.与纯PVAl相比,共混物的温度区间T_m-T_g减小,表明PVP对PVAl的结晶起抑制作用.共混物中PVAl的结晶速度下降,具体表现为PVAl过冷区随PVP含量增加而扩大,动力学速度常数减小,球晶增长速度下降.纯PVAl和共混体系的等温结晶速率均遵循Avrami方程.退火样品的长周期、片晶厚度和过渡层厚度大于相同组成未退火样品.两者长周期随PVP含量增长加显著增大,片晶厚度增长次之,过渡层厚度变化不大.
The crystallization behavior of polyvinyl alcohol (PVAl) / polyvinylpyrrolidone (PVP) blends was studied by DSC, WAXD and SAXS.The crystallinity of PVVAl decreased with the increase of PVP content, and the composition of PVAl ) Was about 50% .Compared with the pure PVAl, the temperature range of the blend T_m-T_g decreases, indicating PVP inhibition of the crystallization of PVAl crystallization rate of PVAl in the blend decreased, specifically as The undercooling region of PVAl expands with the increase of PVP content, the kinetic velocity constant decreases, and the spherulite growth rate decreases.The isothermal crystallization rate of pure PVAl and the blend system follow the Avrami equation.The long period of the annealed sample, the lamella thickness and transition The thickness of the layer is larger than that of the unannealed sample with the same composition.The long period of both increases significantly with the increase of PVP content, the lamella thickness increases secondly, and the thickness of the transition layer does not change much.