The catalyst for direct esterificaton of PBT and synthesis of PBNT copolymer

• Main Authors: Lin, Ching Shivan, 林慶炫
• Other Authors: C.S.Wang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/69692841286502623722

碩士 === 國立成功大學 === 化學工程學系 === 84 === From the development history of polyester PET, transesterification process using DMT has been replaced by the direct esterification process using TPA.The trend will be applicable to polyester PBT,however during the direct esterification TPA(Pka=3.5)can release H+ that will cyclize BDO to THF,the TPA Process can't compete with DMT process.Ti is a good catalyst for the synthesis of PBT,but the yield of byproduct of THF is still high.In order to reduce the amount of THF,some basic catalyst was added to neutrialize the released H+.The experimentalresults indicated that ceriain basic catalyst with suitable Pka can reduce THF formation.Next,in order to improve the heat resistance and modulus of phenyl polyester,some naphthyl polyester have been developed ,such as ,polyethylene 2,6-naphthalate(PEN),polybutylene 2,6-naphthalate(PBN).However the price of starting naphthalene material is pretty high, therefore,copolymers containing both naphthalene and phenylene unit were developed.From DSC,TGA and DMA analysis,PBNT have exhibited better thermal and mechanical properties than PBT.From NMR,we can determine its composition and find its sequence as random.