Modified polycarbonates and a process for preparing high-flow and low-temperature toughness

The present invention discloses a method for preparing a modified polycarbonates and high flowability and low-temperature toughness. Percentage by mass, which is a raw material formulation of the following components: 89.45% ~ 97.89% bisphenol A polycarbonate, 2% to 10% of a reactive polydimethylsiloxane, 0.1% to 0.5% antioxidant and 0.01 to 0.05% of the catalyst; modified polycarbonate of the present invention has a melt flow rate of bisphenol a polycarbonate and carbonate material - increased more than 50% on the basis of a silicone copolymer, a low temperature notched impact at -40 ℃ strength increased about 4-fold, the resulting modified polycarbonate having both low-temperature toughness but also has good processing flowability. The method of the present invention employs a twin screw extruder to achieve a second melt extrusion of bisphenol A polycarbonate to improve flowability and low-temperature toughness, the method is simple and easy to industrialize.