• Polymer(Korea)
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• v.36 no.4
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• pp.513-518
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• 2012

Polyamide 12 (PA12) oligomers (oPA1) were prepared by dispersion polymerization of ${\omega}$-amino carboxylic acid and dibasic acid in a dispersion medium, thermally stable hydrocarbon liquid paraffin, YK-D130 (a step polymerization). The molecular weight and various properties of other oligomeric PAs (oPA2) obtained by bulk polymerization without the medium were compared with those of oPA1s. The oPA1s showed lighter white color and narrower molecular weight distribution than oPA2s at the same molecular weight. Moreover elastomeric poly(ether-block-amide) (PEBA)s were synthesized with oPA1 and oPA2 as hard segments and poly(tetramethylene glycol) (PTMG) as a soft segment. The molecular weight distribution, and mechanical property of the PEBA originated from the both oligomeric PAs were characterized.

• Polymer(Korea)
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• v.38 no.5
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• pp.596-601
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• 2014

Polyamide (PA) oligomers, which are the hard segment of poly(ether-block-amide) (PEBA), presenting thermoplastic and high performance elastomeric properties were prepared by polycondensation between 4-aminobenzoic acid and 12-aminododecanoic acid. Subsequently PEBAs were obtained by addition polymerization of the PA oligomers and various molecular weights of poly(tetramethylene glycol) (PTMG). The structure of the final PEBA was identified by using FTIR and $^1H$ NMR and the thermal properties depending on changes in the structure of hard segment were collected by using DSC and UTM analysis. As the results, the melt temperature ($T_m$), the initial modulus, and the maximum strength of PEBAs increased with an increase in aromatic moiety up to 30% without reducing crystallinity.