Polycarbonate synthesis by the melt phase carbonate‐ester interchange reaction of bisphenol‐A diacetate with dimethyl carbonate

Deshpande, M. M.; Jadhav, A. S.; Gunari, A. A.; Sehra, J.C.; Sivaram, Swaminathan

doi:10.1002/pola.1995.080330411

Cited by 16 publications

(13 citation statements)

References 6 publications

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“…The bulky amorphous chains produce considerable free volume, which results in high ductility and impact resistance 6. The combination of all these characteristics leads to properties such as high optical clarity, percent elongation, impact strength, toughness, heat resistance, and heat deflection temperature 14–16. Uses of BPAPC is spread in many areas, which include construction, electrical, automotive, aircraft, marine, medical (pumps, connectors, fluid administration applications like stopcocks, catheters, syringes, blood oxygenetaors, and kidney dialyzers), and packaging.…”

Section: Introductionmentioning

confidence: 99%

Biodegradation of Aliphatic and Aromatic Polycarbonates

Artham¹,

Doble²

2007

Macromolecular Bioscience

310

155

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Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.

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Section: Introductionmentioning

confidence: 99%

Biodegradation of Aliphatic and Aromatic Polycarbonates

Artham¹,

Doble²

2007

Macromolecular Bioscience

310

155

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“…Phosgene is also a corrosive and expensive substance, and the method produces wasted sodium chloride contaminated with organic substances 6. Because there is increasing pressure to avoid the use of chlorinated organic solvents in the chemical industry, the search for a safer and an environmentally benign processing route to PC that does not involve phosgene and chlorinated solvents is required 5, 7, 8…”

Section: Introductionmentioning

confidence: 99%

A new, nonphosgene route to poly(bisphenol a carbonate) by melt‐phase interchange reactions of alkylene diphenyl dicarbonates with bisphenol A

Sweileh

A-Hiari

Aiedeh

2008

J of Applied Polymer Sci

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This article describes a new, nonphosgene method for the synthesis of poly(bisphenol A carbonate) (PC). The method involves three steps: the reaction of an aliphatic diol with phenyl chloroformate to form an alkylene diphenyl dicarbonate, the reaction of the alkylene diphenyl dicarbonate with bisphenol A to produce an aromatic–aliphatic polycarbonate, and the thermal treatment of the polycarbonate at 180–210°C under a stream of nitrogen with Ti(OBu)4 to give PC and a cyclic alkylene carbonate. The method furnished low to moderate molecular masses of PC upon the complete elimination of the aliphatic moieties. The approach may be considered a new method, based on polycarbonate thermochemical degradation, for the synthesis of cyclic aliphatic carbonates. The obtained polymers were characterized by intrinsic viscosity and IR, 1H‐NMR, and 13C‐NMR spectroscopy. The thermal treatment step was conducted in a glass reaction tube at 180–210°C under a stream of nitrogen, and the reaction was completed by heating to 250°C. In the thermal treatment step, semisolid effluents composed of cyclic alkylene carbonates were formed and subsequently eliminated from the reaction mixture. Heating to 250°C under nitrogen or under a dynamic vacuum furnished the pure aromatic PC residue. This intrachange reaction provides a flexible method for the synthesis of polycarbonates with alkylene diols containing two or three methylene groups, from which the pure PC homopolymer can be prepared. The potential of this approach was demonstrated by the successful synthesis of PC homopolymer from five different polycarbonates with a bisphenol A unit linked to 1,2‐propylene, 1,3‐propylene, 2‐methyl‐1,3‐propylene, 2,2‐dimethyl‐1,3‐propylene, and 1,3‐butylene as the alkane chains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

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“…Deshpande et al 27 also reported that the higher content of carbonate-ended oligomer led to the higher molecular weight of the polymer in the reaction of BPA diacetate with DMC. 27,28 It was proposed to replace BPA with BPA diacetate or 1,4-bis(hydroxymethyl) cyclohexane 26 because of the low activity of the transesterification of BPA and DMC.…”

Section: Introductionmentioning

confidence: 94%

“…[25][26][27][28][29] Shaikh et al 25 and Haba et al 29 reported that the methylcarbonate-ended oligomers from the transesterification of BPA and DMC were most reactive in producing high molecular weight polymers in the postpolycondensation step compared with hydroxyl-ended oligomers. Deshpande et al 27 also reported that the higher content of carbonate-ended oligomer led to the higher molecular weight of the polymer in the reaction of BPA diacetate with DMC. 27,28 It was proposed to replace BPA with BPA diacetate or 1,4-bis(hydroxymethyl) cyclohexane 26 because of the low activity of the transesterification of BPA and DMC.…”

Section: Introductionmentioning

confidence: 99%

“…It has a great advantage that there is no need to obtain DPC, whose economical synthesis by a phosgene‐free method is not easy. There are a few reports on the synthesis of polycarbonate precursor using DMC directly 25–29. Shaikh et al25 and Haba et al29 reported that the methylcarbonate‐ended oligomers from the transesterification of BPA and DMC were most reactive in producing high molecular weight polymers in the postpolycondensation step compared with hydroxyl‐ended oligomers.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of polycarbonate precursors synthesized from catalytic reactions of bisphenol‐A with diphenyl carbonate, dimethyl carbonate, or carbon monoxide

Kim

Lee

2002

J of Applied Polymer Sci

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Transesterification of bisphenol-A with diphenyl carbonate or dimethyl carbonate, and direct oxidative carbonylation of bisphenol-A were compared to obtain polycarbonate precursors for phosgene-free polycarbonate synthesis. The melt-transesterification of bisphenol-A and diphenyl carbonate occurred readily to produce reactive precursors without a significant equilibrium constraint. On the other hand, the transesterification of bisphenol-A and dimethyl carbonate showed a serious equilibrium limitation in obtaining reactive polycarbonate precursors leading to high molecular weight polymers, and coproduced a significant amount of methylated bisphenol-A. The direct oxidative carbonylation of bisphenol-A with CO produced diphenolic-ended oligomers and a significant amount of by-products, which are the least reactive in the subsequent polycondensation step of the phosgene-free polycarbonate process. A novel method to synthesize the reactive polycarbonate precursors was proposed that employed the coupled oxidative carbonylation of both bisphenol-A and phenol.

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Polycarbonate synthesis by the melt phase carbonate‐ester interchange reaction of bisphenol‐A diacetate with dimethyl carbonate

Cited by 16 publications

References 6 publications

Biodegradation of Aliphatic and Aromatic Polycarbonates

Biodegradation of Aliphatic and Aromatic Polycarbonates

A new, nonphosgene route to poly(bisphenol a carbonate) by melt‐phase interchange reactions of alkylene diphenyl dicarbonates with bisphenol A

Comparison of polycarbonate precursors synthesized from catalytic reactions of bisphenol‐A with diphenyl carbonate, dimethyl carbonate, or carbon monoxide

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