1.Hips is a kind of impact modified PS, which is composed of PS and rubber. According to the modification range of hips, it can be divided into three categories: medium impact PS,high impact PS and ultra-high impact PS.
2.Hips can be produced by mechanical blending and graft copolymerization.
The composition of HIPS by mechanical blending method is PS and rubber polymer, and the rubber mainly includes styrene butadiene rubber, styrene and styrene, etc. The impact strength of hips blended with 10% - 15% styrene butadiene rubber was increased by 2 times, which belonged to medium impact PS; while PS / styrene butadiene rubber / SBS ternary blend was ultra-high impact PS, and the surface gloss of the products was high.
3.HIPS produced by graft copolymerization can overcome the disadvantage of uneven dispersion of rubber phase by blending, and has become the main method of HIPS. Hips was copolymerized with styrene monomer and 5% - 10% rubber.
