偏氯乙烯/丙烯腈/苯乙烯悬浮共聚合动力学

本文研究了偏氯乙烯（ＶＤＣ）／丙烯腈（ＡＮ）／苯乙烯（Ｓｔ）三元悬浮共聚合体系的聚合机理、共聚速率、非聚物组成及其特性粘度的影响因素。实验表明随着投料配比的改变，可分成四个不同聚合机理区域。Ｓｔ对ＶＤＣ／ＡＮ／Ｓｔ三元悬浮共聚有缓聚作用。ＶＤＣ三元悬浮共聚速率可用半经验模型，ｄＣ／ｄｔ＝αＣ＾β「Ⅰ」ｏ＾γｅｘｐ（－γｋｄｔ）描述，由实验得到模型参数γ值为２．２４，模型参数α、β是聚合温度与引发剂浓度的函数。ＶＤＣ－ＡＮ－Ｓｔ三元悬浮共聚物存在着较宽的ＶＤＣ组成分布，并受到单体ＡＮ水溶性的影响，经ＡＮ动态相平衡校正后，可预测ＶＤＣ三元共聚物组成。ＶＤＣ－ＡＮ－Ｓｔ共聚物的特性粘度随着转化率的升高而增大。在相同引发剂用量下，高转化率ＶＤＣ－ＡＮ－Ｓｔ共聚物特性粘度的对数与温度的倒数成线性关系。

Kinetics of Vinylidene Chloride / Acrylonitrile / Styrene Suspension Polymerization

In vinylidene chloride(VDC)/acrylonitrile(AN)/styrene(St) suspension polymerization system, polymerization mechanism, copolymerization rate, copolymer composition and intrinsic viscosity were investigated. Experimental results show that polymerization mechanism of VDC/AN/St can be divided into four regions with different initial monomer feeding ratios. Monomer St has somewhat inhabitation role in VDC polymerization. Copolymerization rate of VDC/AN/St suspension system can be described by semiempirical model dC/dt=(C(I]0( exp(-( kdt), where (, ( and ( are the model parameters.Wide VDC copolymer composition distribution was observed for VDC/AN/St terpolymerization. Besides reactivity ratio, the composition of VDC-AN-St terpolymer is also affected by the AN water solubility. After AN dynamic equilibrium between aqueous phase and monomer phase during polymerization has been considered, the VDC copolymer composition can be well predicted. Intrinsic viscosity of VDC-AN-St terpolymer increases with conversion. At the same initiator concentration, the logrithm of intrinsic viscosity of VDC-AN-St terpolymer with high conversion is a linear function of reciprocal temperature.