The Improvement Of Expandable Polystyrene Producted By Suspension Polymerisition

This paper is about a project cooperated by Petrol China Dalian Petrol ltd. and Beijing University of Chemical Technology. In this paper, in order to guide industrial production and provide theoretical and practical basis, expandable polystyrene (EPS) was prepared via suspention polymerization, and influence of the factors affecting the quality of products was found.During experiment, the factors which effected on particle size, quanlitied rate and small size rate of EPS were analyzed. The relationship between particle size, qualified rates, small size rate of EPS and dispersant agent amount, string speed, pentane amount, water-oil were found. The result showed that with the increasing of string speed the average diameter was decreased; the quanlitied rate was increased. The average diameter was increased and the quanlitied rate was decreased with the increasing of diapersant agent amount. Particle quanlitied rate was improved to 89% which is more than 75%, the Dalian petrochemical products quanlitied rate.The small size rate goes down and then up with the increasing of pentane amount, and goes to minimum 0.42% when pentane amount is 2.67%, less than small size rate of Dalian petrochemical products which is 5%.Glass transition temperature of EPS decreases with the increasing of pentane amount. The maximum glass transition temperature 103℃was obtained by changing the producting process..Temperature process has great influence on The molecular weight of product, the lowest molecular weight was obtained in process C, the pentane amount has great influence on molecular weight, which decreases with the increasing of pentane amount, the temperature process has effect on molecular weight of EPS, the maximum molecular weight was obtained by changing the producting process.The string speed has effect on pentane disperating and the best disperating condition was obtained at a string speed of 400r/min. The pentane amount also has great effect on pentane disperating and the best disperating condition was obtained at 2.14% pentane amount. The best pentane disperating witch is better than disperating of Dalian petrochemical products was found by changing the producting process.