Process Research Of Synthesis Of Aliphatic Polycarbonate

Aliphatic polycarbonates have good flexibility,biocompatibility and biodegradability,which can be completely degraded into neutral glycols and carbon dioxide.They have wide use in film materials,elastomers,biodegradable materials,coatings,adhesives,etc.Aliphatic polycarbonates have poor thermal stability and mechanical properties due to the compliant molecular chains.In this paper,1,4-cyclohexanedimethanol,a cycloaliphatic glycol with high symmetry in structure,is used as raw material to improve the thermal stability of synthetic aliphatic polycarbonates.Due to the high glass transition temperature of 1,4-cyclohexanedimethanol as a raw material for the synthesis of aliphatic polycarbonate glass,aliphatic diols are added to the raw materials,so that the glass transition temperature of the synthesized product is reduced,and the flexibility is extended.In this paper,dimethyl carbonate and 1,4-cyclohexanedimethanol were used as raw materials,and sodium methoxide was used as a catalyst.At a highest reaction temperature of 180?,an atmospheric reaction for 9 hours,a decompression reaction for 10 hours,and a vacuum degree of vacuum of 6 kPa,a synthesis was performed.Aliphatic polycarbonate with a weight average molecular weight of 10568g/mol.Dimethyl carbonate,1,4-cyclohexanedimethanol,1,6-hexanediol/1,8-octanediol as raw materials,sodium methoxide as a catalyst,highest reaction temperature of 180?,atmospheric pressure reaction for 9 hours,decompression reaction for 12 hours,and a vacuum degree of vacuum of 6 kPa,minus The aliphatic polycarbonate with a weight average molecular weight of 8000-11000g/mol was synthesized.The molecular weight distribution was narrow.The three different aliphatic polycarbonates synthesized in this study have been studied and found that their molecular structure is disordered,there is no crystallinity,and product transparency,flexibility,ductility and impact resistance are good.The glass transition temperature of the product synthesized by the reaction of dimethyl carbonate and 1,4-cyclohexanedimethanol is 25?,and the thermal stability is the best.The aliphatic polycarbonate synthesized by adding 1,8-octanediol to the raw material has a lower glass transition temperature and better low-temperature flexibility.