Study Of The Copolymerization Of Carbon Dioxide And 1,2-butylene Oxide

The copolymerization of carbon dioxide and epoxy-alkanes to prepare aliphatic polycarbonate material is a promising new method of polymer material synthesis.This process not only uses the cheap waste resource CO₂as raw material,but also can produce biodegradable polycarbonate material,which has a wide application prospect.After years of development,the copolymer of carbon dioxide and propylene oxide PPC has been industrialized,but the glass transition temperature of PPC is low,which makes it brittle at low temperature and poor dimensional stability at high temperature when it is used as a thin film material.It is urgent to develop more CO₂-based polymer materials with new structures and properties.These works focus on the following two parts,one is to prepare polycarbonate through the copolymerization of1,2-butylene oxide（BO）with carbon dioxide to synthesis a novel CO₂-based polycarbonate with high molecular weight then introduce third monomer for terpolymerization,and study its properties and structure.The second is to prepare low molecular weight polycarbonate-ether diols through the copolymerization of 1,2-butylene oxide and carbon dioxide,and study the polymerization rule.The main research results are as follows:1.Using Schiff base cobalt as catalyst,1,2-butylene oxide and CO₂as main raw materials,and through copolymerization with propylene oxide and cyclohexane oxide,a series of polycarbonate materials were prepared.The effects of polymerization conditions and copolymer composition on polymer structure and properties were systematically investigated.Polycarbonate with adjustable glass transition temperature（T_g）（11.2～67.8 ℃）and hydrophilicity（Contact Angle 85.2～95.2°）was prepared by adjusting the feeding ratio of epoxides.Therefore,this terpolymer method provides an effective method to regulate the surface hydrophobicity and biodegradability of CO₂-based polymers.2,Using Zn-Co bimetallic cyanide（Zn-Co-DMC）as catalyst to catalyze the copolymerization of 1,2-butylene oxide and carbon dioxide to synthesis oligo polycarbonate-ether diols.In this work,firstly,the effects of different chain transfer agents on oligomerization were investigated.Then sebacic acid（SA）was chosen as chain transfer agent to systematically investigate the effects of reaction time,reaction temperature,reaction pressure and the amount of chain transfer agent on oligomerization and the molecular weight and distribution of products.The results showed that the molecular weight of diols was proportional to the molar ratio of BO/SA added.Higher pressure and lower time were conducive to the increase of the content of carbonate units in polycarbonate-ether diols,the molecular weight of diols was controllable and the content of carbonate units was up to 68.6%.