高腈含量SAN树脂制备工艺研究

The study on the process of preparation for SAN resin with high acrylonitrile content

研究了在连续热引发SAN聚合实验装置中制备高丙烯腈含量的SAN树脂的工艺。研究发现:制备高腈SAN树脂,控制聚合釜气相中丙烯腈比例是关键因素,气相中过高的丙烯腈含量会使分子量分布变宽,树脂性能恶化。提出了在体系中引入少量低沸点的第二溶剂,与乙苯一起形成混合溶剂的新工艺,可以有效降低聚合釜气相中丙烯腈的比例,所制得高腈SAN树脂分子量分布窄,力学性能优异。利用该工艺可以在通用装置上生产高腈SAN,可以在高固含量下进行,并且不会降低装置的产能。

The process of preparation for SAN resin with high acrylonitrile content in a continuous thermally initiated SAN polymerization experimental device was studied. It was found that controlling the proportion of acrylonitrile in the gas phase of the polymerization reactor is the key factor for the preparation of high AN content SAN resin, with excessively high AN content in the gas phase the molecular weight distribution will be widened and the mechanical properties are deteriorated. A new process of introducing a small amount of second solvent with low boiling point into the system to form a mixed solvent with ethylbenzene is proposed, which can effectively reduce the proportion of acrylonitrile in the gas phase of the polymerization reactor, and the obtained high AN content SAN resin has a narrow molecular weight distribution and excellent mechanical properties. Using this process, high AN content SAN can be produced on a general-purpose SAN production system, at high solid content, without reducing production capacity.