Poly(ethylene terephthalate) (PET) were synthesized by using a liquid-phase catalyst of 4wt% Sb
2O
3 solution dissolved in ethylene glycol(EG) with neopentyl glycol (NPG) or 1,3-propanediol(PD). The characteristics of reaction behavior during the polycondensation [inherent viscosity(I.V.), number of mole(n), rate of reaction, molecular weight distribution (MWD)] were studied. And then properties depending on the amount of catalyst(500, 400, 300, 200, 100 ppm) were investigated without thermal stabilizer. In the study of reaction kinetic, polycondensation reaction using liquid-phase catalysts exhibits faster rate than that using Sb
2O
3 powder catalyst. Especially, PET polycondensation using EG-NPG(Sb
2O
3 4%) 500 ppm and EG-PD(Sb
2O
3 4%) 400 ppm catalysts showed the highest degree of polycondensation and reaction kinetic. After all, increase of degree of polycondensation (DP) was kept by stabilization as effect of NPG and PD. The MWD of using EG-NPG(Sb
2O
3 4%) and EG-PD (Sb
2 O
3 4%) catalysts exhibited lower in polydispersity than that using Sb
2O
3 powder catalyst. It seems that solubility parameter has close reaction to the polycondensation behavior of PET. At DSC thermogram, melting point(T
m) of PET prepared using EG-NPG;(Sb
2 O
3 4%) and EG-PD(Sb
2O
3 4%) catalysts were alike temperature.
Poly(ethylene terephthalate) (PET)를 중합에 있어서 Sb
2O
3 분말을 4wt.% glycol[ethylene glycol (EG), neopentyl glycol(NPG), 1,3-propanediol (PD)]에 용해시킨 액상촉매를 사용하여 열안정제의 사용 없이 중합하고, 중합한 PET의 특성인자[고유점도 (inherent viscosity, I.V.), 몰수(n), 반응속ㄱ, 분자량분포(MWD)]를 조사하였다. 반응속도에 있어서는 Sb
2O
3 분말촉매 보다 액상촉매를 사용한 경우가 빠른 반응속도를 나타내고, 특히 EG-NPG(Sb
2O
3 4%) 500 ppm과 EG-PD(Sb
2O
3 4%) 400ppm의 촉매양으로 중합한 경우가 높은 중합도와 빠른 반응 속도를 나타냄을 알 수 있었다. 분자량분포에 있어서는 Sb
2O
3 분말촉매 보다 EG-NPG (Sb
2O
3 4%)와 EG-PD (Sb
2O
3 4%)촉매를 사용한 PET가 낮은 분자량분포지수 (polydispersity, M
w/M
n)를 나타냄을 알 수 있었다. 즉 저분자물질이 반응시간이 지남에 따라 중합에 관여하여 중합도가 증가함을 알 수 있었다. 그리고 열적변화는 EG-NPG(Sb
2O
3 4%) 촉매의 경우와 EG-PD (Sb
2O
3 4%)촉매를 사용한 경우의 융점 (T
m)이 거의 같은 온도를 나타냄을 알 수 있었다.
Keywords: inherent viscosity; reaction kinetic; solubility parameter; MWD; DSC