Compositions and articles of manufacture containing branched polycarbonate

摘要

A polycarbonate containing composition comprising a peak melt viscosity of at least 8,000 poise when measured using a parallel plate melt rheology test at a heating rate of 10° C./min at a temperature of between about 350° C. to about 450° C., and wherein a molded article of the composition has a UL 94 VO rating at a thickness of 1.0 mm, 1.5 mm, 2.0 mm, or between 1.0 mm and 2.0 mm is disclosed.

主权项

1. A composition comprising:
a first polycarbonate, wherein the first polycarbonate comprises
a repeating structural unit of the following formula wherein at least 60 percent of the total number of R1 groups contain aromatic groups and the balance thereof are aliphatic or alicyclic groups;wherein the first polycarbonate was formed in the presence of an end-capping agent and the end-capping agent is not cyanophenol;wherein the first polycarbonate has a branching level of at least about 2%;wherein the polycarbonate has a weight average molecular weight of 20,000 g/mole to 54,843 g/mole as measured by gel permeation chromatography using polycarbonate standards; andwherein the first polycarbonate is prepared byselecting the branching level, the weight average molecular weight, and the end-capping agent such that the first polycarbonate has a calculated peak melt viscosity of at least 25,000 poise as calculated by a peak melt viscosity equation as follows:
calculated peak melt viscosity=−57135.91+36961.39*BL+14001.13*MW1/3−46944.24*pKa−322.51*BL*MW1/3−2669.19*BL*pKa+215.83*MW1/3*pKa+1125.63*BL2−200.11*MW2/3+2231.15*pKa2, wherein BL is determined by dividing a number of moles of branching agent by a total moles of bisphenol from which the first polycarbonate is derived, MW is the weight average molecular weight, and the pKa is the pKa of the end capping agent; and
wherein a molded article of the first polycarbonate has a UL94 V0 rating at a thickness of 1.0 mm; a flame retardant; and a second polycarbonate derived from at least bisphenol-A, wherein the second polycarbonate is different from the first polycarbonate; wherein a molded article of the composition has a UL94 V0 rating at a thickness of 1.5 mm.