Overview of Polycarbonate Modification

Polycarbonate is a transparent resin with high strength, high toughness, high heat resistance, good shock resistance and processing properties, and excellent shape and color stability. It can be used alone or in blends and alloys, and its consumption is second only to polyamide among the six major engineering plastics. At present, there are three main international polycarbonate industrial production technologies: phosgenation interfacial polycondensation method (phosgene method for short), transesterification melt polycondensation method (transesterification method for short, also known as bulk polycondensation method) and non-phosgene method.

Polycarbonate has excellent performance, but due to the high rigidity of the molecular chain, high steric hindrance, high melt viscosity of the product, and difficult processing; and poor solvent resistance and wear resistance, its modification research has become The most important subject of its application research, the main approach is polymer alloying.

PC/PS alloy is a partially compatible, amorphous/amorphous system. Adding PS to PC can improve the processing fluidity of PC, and adding a small amount of PS can greatly reduce the melt viscosity. Both PC and PS are transparent materials, and the refractive indices of the two are very close, so the PC/PS alloy is transparent and has good optical properties. The composition of PC/PS alloy has a great influence on the mechanical properties, thermal properties and processing properties of the alloy.

The alloy material made by blending PBT and PC can improve the fluidity of PC, improve its processing performance and chemical resistance. Since PBT is a crystalline polymer, it is prone to phase separation when blended with PC, the interface is not well bonded, and the impact toughness is not ideal. Usually, a certain amount of elastomer is added to improve the impact strength of the blend, such as thermoplastic elastomer ethylene- Zinc salt of methacrylate copolymer. Adding ethylene/vinyl acetate copolymer can further enhance compatibility and improve impact strength.