Carbonate blend polymer compositions comprising a high molecular weight branched carbonate polymer component and methods for their preparation

摘要

Novel carbonate polymer blend compositions and processes for their preparation are disclosed where an amount of a high molecular weight branched carbonate polymer component (HMWB PC) is combined with a second, lower molecular weight polycarbonate. A HMWB PC component is selected which is homogeneously dispersible in a blend with the second component. A preferred aspect of the invention is directed to intermediate compositions and processes for their use where the second PC is combined with a HMWB PC precursor having latent themally reactive moieties which can be activated to produce a desired and controlled level of high molecular weight, branched carbonate polymer component. Arylcyclobutene moleties are found to be preferred latent thermally reactive moleties. The carbonate polymer blends according to the present invention have surprisingly improved combinations of physical properties, thermal stability, color, melt strength, transparency and processability. When shaped or molded into various types of articles, the articles posses these very desirable properties and are additionally able to be provided with a low gloss or matte surface. These polymeric compositions are well suited for use in preparing molded articles, such as injection molded articles; composite or blend materials with further filler or blend components; extruded articles such as sheet, fiber or film; and blow molded or thermoformed articles.