Hamid Reza Azimi - Institute of Polymeric Materials, Polymer Engineering Department, Sahand University of Technology, P.O.Box ۵۱۳۳۵-۱۹۹۶, Tabriz, Iran
Mostafa Rezaei - Institute of Polymeric Materials, Polymer Engineering Department, Sahand University of Technology, P.O.Box ۵۱۳۳۵-۱۹۹۶, Tabriz, Iran
Farhang Abasi - Institute of Polymeric Materials, Polymer Engineering Department, Sahand University of Technology, P.O.Box ۵۱۳۳۵-۱۹۹۶, Tabriz, Iran

In this work, we synthesized styrene-methyl methacrylate (St-MMA) copolymer particles by suspension polymerization process to study the foaming dynamics via visual batch foaming apparatus. The weight ratio of St-MMA was 70 to 30, respectively. The foaming system consisted of the self-sealing observation cell equipped with two glass windows and a stereo microscope attached with a high speed digital camera as well as pressure and temperature controller. The required pentane pressure was supplied by heating of a small pentane flask. The synthesized copolymer particles impregnated by pentane and then foaming dynamics were recorded after a rapid pressure release. Different foaming conditions, like temperature, impregnation time and impregnation pressure on the expansion ratio of St-MMA copolymer was investigated. It was concluded that impregnation pressure, time and temperature have different effects on the foaming ratio at lower and higher impregnation pressures than 3 bar

St-MMA copolymer, Foaming dynamics, n-pentane, Suspension polymerization