Cationic dyeable modifiers (CDM) for polyethylene terephthalate (PET), bis(-2-hydroxyethyl)-5-sodium sulfoisophthalate (HESP) or 5-sodium sulfodimethyl isophthalate(MSP) was reacted with bis(-2-hydroxyethyl)-terephthalate (BHET). The reaction variables were temperature, time and the concentration of the CDM. The reaction coefficient (k) were determined from the slope of the plot of In (1-Y/100)vs. t, because it was investigated as 1st order reaction. The reaction coefficient was used for the calculation of the activation energy. The activation energy between BHET and HESP was lower than that between BHET and MSP because the intramolecular hydrogen bonding was predominant in both BHET and HESP. The hydrogen bonds might increase electron density of oxygen in -OH group and reduce the electron density of the ester carbonyl carbon, resulting easier access of the -OH group to carbonyl carbon at the rate determining step.

캐니온 가염개질제, bis(-2-hydroxyethyl)-5-sodium sulfoisophthalate (HESP)와 5-so-dium sulfo dimethylisophthalate (MSP)의 구조가 에스테르 축합반응속도에 미치는 영향을 알아보기 위하여 bis(-2-hydroxyethyl)terephthalate (BHET)와 각각 반응시켰고 그 반응에서의 변수는 반응온도, 시간, 개질제의 농도 등이었고, ln (1-Y/100)가 t와의 관계가 직선관계를 보였기 때문에 1차 반응으로 간주하고 속도상수(k)를 구하였다. 이 속도상수는 반응 활성화 에너지 계산에 이용되었고 BHET와 HESP의 반응 활성화 에너지가 BHET와 MSP와의 활성화 에너지보다 더 작았으며 이것은 BHET와 HESP 모두가 분자내 수소결합을 하기 때문에 말단-OH기의 산소가 전기적인 극성이 증가하여 카보닐기의 탄소에 쉽게 접근하여 율속단계에서의 반응속도가 커진 것으로 추측되었다.

Keywords: copolymerization kinetics of PET; cationic dyeable modifier; BHET