Polycarbonate

About: Polycarbonate is a research topic. Over the lifetime, 14032 publications have been published within this topic receiving 141740 citations. The topic is also known as: PC & Polycarbonate, PC.

Polymer mixture comprising an aromatic polycarbonate, a styrene-containing copolymer and/or graft polymer and a phosphate based flame-retardant; articles formed therefrom

Abstract: The invention relates to a polymer mixture which comprises an aromatic polycarbonate, a styrene­-containing copolymer and/or a styrene-containing graft polymer and a flame-retardant. It has been found that the use of a certain type of flame-retardants, namely oligomeric phosphates leads to a polymer mixture having improved properties. In particular to a polymer mixture having a good combination of flame retardancy, non-­juicing characteristics of the flame retardant, good plastifying effect and good heat resistance.

The effect of thermal pretreatment on the strength of polycarbonate

Abstract: The effect of preheat treatment at temperatures below the glass transition for various periods of time on selected properties of molded polycarbonate has been studied. Changes in tensile and flexural strength as functions of time and preheat temperature (80–140°C.) were determined and these are discussed in relation to changes in the nature of the β-transition region and the influence of the glass transition region. It is suggested that the preheat treatment produces a greater degree of order within the amorphous region of the polymer, resulting in an increase in strength at temperatures up to 132°C. The strength of the polycarbonate before and after heat treatment appears to be independent of the presence of the equilibrium water content.

Transparent Polycarbonate Polyester Composition and Process

Abstract: Disclosed is a transparent/translucent molding composition and process for making prepared from an impact modifier and a resin blend of polycarbonate and a cycloaliphatic polyester having a matching index of refraction.

Switchable Catalysis Improves the Properties of CO2-Derived Polymers: Poly(cyclohexene carbonate-b-ε-decalactone-b-cyclohexene carbonate) Adhesives, Elastomers, and Toughened Plastics.

Abstract: Carbon dioxide/epoxide copolymerization is an efficient way to add value to waste CO2 and to reduce pollution in polymer manufacturing. Using this process to make low molar mass polycarbonate polyols is a commercially relevant route to new thermosets and polyurethanes. In contrast, high molar mass polycarbonates, produced from CO2, generally under-deliver in terms of properties, and one of the most widely investigated, poly(cyclohexene carbonate), is limited by its low elongation at break and high brittleness. Here, a new catalytic polymerization process is reported that selectively and efficiently yields degradable ABA-block polymers, incorporating 6-23 wt % CO2. The polymers are synthesized using a new, highly active organometallic heterodinuclear Zn(II)/Mg(II) catalyst applied in a one-pot procedure together with biobased e-decalactone, cyclohexene oxide, and carbon dioxide to make a series of poly(cyclohexene carbonate-b-decalactone-b-cyclohexene carbonate) [PCHC-PDL-PCHC]. The process is highly selective (CO2 selectivity >99% of theoretical value), allows for high monomer conversions (>90%), and yields polymers with predictable compositions, molar mass (from 38-71 kg mol-1), and forms dihydroxyl telechelic chains. These new materials improve upon the properties of poly(cyclohexene carbonate) and, specifically, they show good thermal stability (Td,5 ∼ 280 °C), high toughness (112 MJ m-3), and very high elongation at break (>900%). Materials properties are improved by precisely controlling both the quantity and location of carbon dioxide in the polymer chain. Preliminary studies show that polymers are stable in aqueous environments at room temperature over months, but they are rapidly degraded upon gentle heating in an acidic environment (60 °C, toluene, p-toluene sulfonic acid). The process is likely generally applicable to many other lactones, lactides, anhydrides, epoxides, and heterocumulenes and sets the scene for a host of new applications for CO2-derived polymers.