Synthesis of poly(ester amide)s by the melt polycondensation of semiaromatic polyesters with ethanolamine and their characterization

Abstract

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.

Comparison of single‐ versus two‐stent techniques in treatment of unprotected left main coronary bifurcation disease

“…Poly(ester amide)s (PEAs) have been proposed as a class of materials having the potential to exhibit optimal properties for a diverse range of biomedical applications 19. By definition they comprise both ester and amide linkages in their backbones, and several different classes of backbones have been proposed 20–27. The PEAs of interest in the present work are those comprising diols, diacids, and α‐amino acids as illustrated in Figure 1.…”

Mass Spectrometry of Synthetic Polymers

“…The same MS method was used to investigate the effect of long time aging on the chain end of poly( p -methoxystyrene) . Furthermore, the characterization of poly(ether imide)s , , poly(amidoamines), poly(ester amide)s , poly(epichlohydrin) , telechelic poly( N -isopropylacrylamides) , cyclic poly(lactides) , enantiomeric poly(α-methyl-α-ethyl-β-propiolactones) , and multicyclic poly(ether sulfone)s by MALDI-TOF MS was reported. Liu and Mishra described the atom-transfer radical polymerization of menthyl acrylate .…”

Catalyzed chain extension of poly(butylene adipate) and poly(butylene succinate) with 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline)

“…Harashina at al. 32 studied the thermal decomposition of ethanolaminemodified PET and [poly(ester amide)] and found that the modified poly(ester amide) was less stable than PET. They proposed a decomposition method to demonstrate this phenomenon.…”