Polystyrene molecular weight is usually 5~20, high molecular weight, so some kind of processing difficulty will arise. Mechanical properties of PS, and with increasing temperature, stiffness, modulus of elasticity, tensile strength, impact strength, decreased, and elongation rate. PS transparent, light transmission rate of 88~92%, after acrylic polymer, refractive index 1.59~1.60. It can be used as optical elements, but after exposure to sunlight, prone to yellowing and turbidity. PS there are major disadvantages are embrittlement and low heat-resistance. Modification of PS, such as rubber-modified high impact PS (HIPS), MMA--butadiene-styrene (MBS), a (acrylonitrile) b (butadiene) s, in the industry's most widely used is ABS plastic. Excellent, durable insulation: extrusion, thermal conductivity for 0.028w/MK, has the characteristics of high heat resistance and low linear expansion. Its thermal conductivity is much lower than other insulation materials, such as: EPS thermal insulating mortar, cement board, polyurethane foam, perlite, and so on. And because material has stable chemical and physical structure of benzene, make sure that the thermal insulation properties of a lasting and stable.