Polycarbonates

Abstract

Polycarbonates are an unusual and extremely useful class of polymers. The vast majority of polycarbonates are based on bisphenol A (BPA) and sold under the trade names Lexan, Makrolon, Calibre, and Panlite. BPA polycarbonates having high glass‐transition temperatures are widely regarded for optical clarity and exceptional impact resistance and ductility at room temperature and below. Other properties such as modulus, dielectric strength, or tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respective glass‐transition temperatures. Polycarbonates are prepared commercially by two processes: Schotten‐Baumann reaction of phosgene and an aromatic diol in an amine‐catalyzed interfacial condensation reaction, or via base‐catalyzed transesterification of a bisphenol with a monomeric carbonate such as diphenyl carbonate. Important products are also based on polycarbonates in blends with other polymers, copolymers, branched resins, flame‐retardant compositions, foams, and other materials. Polycarbonate, produced globally, has been the object of research studies, owing to its widespread utility and unusual properties. This article summarizes the preparation, properties, and utility of polycarbonates.

A New, Crystalline High Melting Bis(hydroxymethyl)polycarbonate and Its Acetone Ketal for Biomaterial Applications

“…Whereas aromatic polycarbonates have achieved wide application and great importance as polymeric materials since 1954, aliphatic polycarbonates have been less interesting due to their poor thermal stability and easy hydrolysis. During the past decade, increasing attention has been paid to aliphatic polycarbonates for their potential in the medical field and in the environmental control of plastics. − Aliphatic polycarbonates derived from the five- and six-membered ring monomers have been thoroughly studied for their academic or biomedical value. − For example, poly(ethylene carbonate) ( PEC ) was reported to be totally eroded within 2 weeks in vivo. ,, However, introduction of a substituent methyl group, i.e., poly(1,2-propylene carbonate) ( PPC ), completely suppresses bioresorption. , The in vitro degradation of poly(trimethylene carbonate) ( PTMC ) in pH 7.4 buffer solution for 30 weeks at 37 °C only resulted in 9% weight loss and 7% molecular weight decrease, which was approximately 20 times less than that of poly(ε-caprolactone) .…”

Industrialization and Expansion of Green Sustainable Chemical Process: A Review of Non-phosgene Polycarbonate from CO2

“…The worldwide demand for PC exceeded about 3.6 million tons in 2016. The reasons for the largest demand of PC in the engineering plastics is due to excellent properties, such as outstanding impact resistance, good transparency, high heat resistance, and high flame retardancy. − …”

Environmentally-Friendly Synthesis of Carbonate-Type Macrodiols and Preparation of Transparent Self-Healable Thermoplastic Polyurethanes

“…Bulk production processes of polycarbonates typically use phosgene or DPC for generating carbonate linkages [ 36 , 37 , 38 ]. For aliphatic carbonate-type macrodiols, DMC can be a greener alternative because it does not generate acids or phenols.…”