Polycarbonate homopolymers synthesis

Since the introduction of BPA polycarbonate homopolymer, researchers have continually sought to expand the usefulness of these materials via synthesis of new polycarbonate homo- and copolymers. This section will focus on the copolymers that are commercially available. For a more extensive examination of noncommercial, non-BPA polycarbonates, several excellent reviews may be found at [90-93]. Copolymer production generated by reactive blending, coextrusion, and/or compatibilizing materials (e.g., grafting) will also not be discussed. However, a historical overview of commercial alloys and blends may be found in a recent work by Utracki [94]. 

The synthesis and characterization of poly(hexamethylene sebacate-tiimethyl-siloxane) block copolymers, prepared by coupling Cl- or McjNH-terminated dimethylsiloxanes with OH-terminated poly(hexamethylene sebacate), have been studied. The copolymers containing 19—90% siloxane were characterized by n.m.r., viscosity, DSC and CPC. All the polymers were found to be crystalline. The copolymers containing <69% siloxane, when cast from solution or melts, indicated a reduction in spherulite size as the siloxane concentration increased, although only a small m.pt. depression was observed. All the copolymers have critical surface tensions similar to dimethylsiloxane homopolymers. Polycarbonate-Siloxane Copolymers.—A model has been proposed to predict the micromorphology and mechanical properties of block copolymers of bisphenol-A polycarbonate and poly(dimethylsiloxane). N.m.r. data upon 65 35 (wt%) copolymer of poly(dimethylsiloxane) and bisphenol-A polycarbonate, with block lengths of 20—100 monomer units, were found to be in agreement with the predictions of a spin-diffusion model. ... 

This type of SEC-MS hyphenation has been applied to a wide variety of homopolymers and copolymers amongst them are polyacrylates, polyesters, polyethers, polyamides, resins, polycarbonates, proteins, and polystyrene. Synthesis optimization, investigation of the degradation behavior of polymers, polymer aging, and deformulation have been the goals of the analysis. 

---