Semiaromatic poly(ester amide)s (PEAs) were synthesized by the melt polycondensation of ethanolamine (EA) derivatives with dimethyl terephthalate and ethylene glycol in the presence of tetrabutyl titanate as a catalyst, and their crystallization and thermal properties were investigated. The introduction of an amide group into a semiaromatic polyester such as poly(ethylene terephthalate) (PET) produced PEAs (EA-modified PET polymers) with an increase in the melting point. However, these PEAs were found to decompose at a lower temperature than PET on the basis of TGA. Moreover, direct pyrolysis/mass spectrometry measurements suggested that an initial step of the thermal decomposition was a b-CH hydrogen-transfer reaction via a six-member ring transition state at the ester-ethylene-amide unit, at which carbonoxygen bond scission took place to yield carboxyl and N-vinylamide end groups. Furthermore, molecular orbital calculations using trimer models bis [2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl]terephthalate, N-[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl]-4-[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyloxycarbonyl]benzamide, and N,N 0 -bis[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl]terephthalamide strongly supported the idea that the b-CH hydrogen-transfer reaction in the thermal decomposition of PEAs might occur more easily at the methylene group next to the amide group in an ester-ethylene-amide unit rather than at the methylene group next to the ester group in an ester-ethylene-ester unit.

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SynopsisRauical telomerization of diallyl aromatic dicarboxylates, including diallyl phthalate (DAP) and diallyl terephthalate (DAT), was investigated in detail in the presence of CBr4 as a telogen. Telomer yield could be accurately determined by a subsidiary GPC measurement in conjunction with a precipitation method. Telomerization kinetics of diallyl compound in the presence of CBr4 was discussed and the chain transfer constant C C B~~ (= kt,/kp) was estimated to be 57.9 and 53.8 for DAP and DAT, respectively, the values which correspond t o those for one functional group of diallyl compound. The degree of polymerization was significantly dependent on conversion as consequences of the fast consumption of CBr4 and the occurrence of crosslinking reaction. The rate of polymerization was enhanced with the added amount of CBr4, being ascribable to the replacement of the degradative chain transfer by the chain transfer to CBr4, the latter which yields active tribromomethyl radical in lieu of less active allyl radical. Gelation was delayed with an increase in the added amount of CBr4. Preparation of telomer in high yield and its applicability are finally discussed.