树脂类型对PVC溶胶流变性能的影响

Effect of Types of Resin on Rheological Properties of PVC Plastisols

研究了不同生产方法糊树脂制备的聚氯乙烯(PVC)溶胶,在旋转流变仪程序升温模式下的流变性能。通过扫描电子显微镜、激光粒度仪和凝胶渗透色谱仪研究了PVC糊树脂的颗粒形貌、粒度及分布以及相对分子质量及相对分子质量分布特征,从而建立了PVC溶胶流变性能参数与糊树脂特性参数间的关系。结果表明,随着温度的升高,PVC溶胶的储能模量、损耗模量和复数黏度等流变参数呈非正态分布变化趋势,可分为4个阶段:前三阶段,流变参数先降低,后由缓慢升高至急速升高,形成一个肩峰并达到一个最大值,黏度变化趋势与树脂颗粒形态有关;第四阶段,流变参数逐步变小,黏度主要受树脂相对分子质量及相对分子质量分布的影响。

The poly（vinyl chloride）（PVC）paste resins produced with different production methods were used to prepare a series of PVC plastisols,and the rheological properties of these plastisols were investigated by using rotational rheometer at a constant heating rate.The particulate morphology,molecular weight and molecular weight distribution of PVC paste resins were investigated by scanning electron microscope,laser particle analyzer and gel permeation chromatography correspondingly,and the relationship between the rheological properties of PVC plastisols and the characteristic parameters of paste resins were established.The results show that,with the increase of temperature,the rheological curves of PVC plastisols including energy-storage modulus,loss modulus,and complex viscosity tended to show a non-normal distribution.These curves demonstrated a four-stage variation in rheological parameters：（I）decrease,（II）slow rise,（III）rapid rise and maximization（IV）decrease.In the first three stages,the viscosity was mainly affected by the particulate morphology. However,with the gradual decrease of rheological parameters in the fourth stage,the viscosity was mainly affected by the molecular weight and its distribution of PVC paste resins.