Aliphatic polycarbonates thermal properties

Li XH, Meng YZ, Chen GQ, Li RKY (2004) Thermal properties and rheological behavior of biodegradable aliphatic polycarbonate derived from carbon dioxide and propylene oxide. J Appl Polym Sci 94 711-716... 

Modified silicon-containing polycarbonates have been prepared in solution and their transition temperatures assessed. Block copolymers of bisphenol-A-polycarbonate-bisphenol-A-polysulphone and acrylates and methacrylates grafted onto polycarbonate film have also been prepared and evaluated, as have mixed polycarbonate systems based on 2,2 -bis(4-hydroxyphenyl)propane, 2,2 -bis(4-hydroxy-3,5-dibromophenyI)propaneandtetrabromophenophthalein. Molecular relaxations in aliphatic polycarbonates have been studied by the method of thermally-stimulated currents and the thermal ageing of polycarbonates based on polycyclic diphenols has been assessed by studies of mechanical properties. 

This chapter reviews the research and the most relevant progresses in polycarbonates (PC)s science and provides a comprehensive source of information on history, synthesis, processing and applications. The application of different polymerization procedure of the commercial aromatic bisphenol-A polycarbonate (referred herein as PC) and the innovative enzymatic catalysed polymerization of aliphatic polycarbonate are summarized. Due to the high engineering performance of PC polymer, an extensive section on mechanical, electrical, chemical and thermal properties is included. The thermo and photo oxidative behaviours, the hydrolytic stability and the consequent modification on PC chemical structure are also discussed. The development of PC polymeric materials such as composites and blends are also addressed, emphasizing in particular the properties and the applications of impact modified PC blends and even of the PC/Polyester systems. 

Polycarbonates are polyesters of carbonic acid formed by reaction of diols (aromatic, aliphatic or a mixture of both) with a derivative of carbonic acid. The first preparations of polycarbonates were reported by Einhorn in 1898 [155], by reaction of phosgene with resorcinol or hydroquinone in a pyridine solution. Bischoff and van Hedenstrom in 1902 [156] obtained the same aromatic polycarbonates via transesterification with diphenyl carbonate (DPC). Thus the main routes to polycarbonates were established early, but the properties of the products seemed uninteresting. Around 1930 aliphatic polycarbonates were studied by Carothers and van Natta [157]. These carbonates have low melting points and thermal resistance and are not commercially interesting as stand-alone thermoplastics. Low molecular... 

Functional aliphatic polycarbonates were synthesized by Lukaszczyk through the copolymerization of allyl glycidyl ether (AGE) and CO2 (16). Wang also synthesized AGE/CO2 copolymers in addition to other glycidyl ether/C02 based polycarbonates and reported the mechanical and thermal properties of... 

Figure 4 shows the TGA and DSC thermograms for the aliphatic polycarbonates synthesized using catalyst 4. The data for all the thermal analyses are summarized in Table III. Since the thermal properties of the... 

Figure 4. Thermal properties of aliphatic polycarbonates poly(propylene carbonate) (PPC) poly(l,2-butylene carbonate) (PBC) poly(l,2-hex-5-ene carbonate) (PHC) poly(styrene carbonate) (PSC). (a) Thermogravimetric analysis curves (samples were run under an N2 atmosphere with a heating rate of 20 °C/min). (b) Differential scanning calorimetry curves (samples were run under an N2 atmosphere with a heating and cooling rate of 10 °C/min data...

One of the most interesting properties of aliphatic polycarbonates is their clean thermal degradation to gaseous products (5,77). In this paper we describe the synthesis... 

Although the synthesis of these polycarbonates has been accomplished, few reports have described the thermal and mechanical properties of these materials (21). To gain a better understanding of the potential applications for these materials, a variety of aliphatic and alicyclic polycarbonates must be synthesized and studied. 

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