Thermal properties of Poly(trimethylene terephthalate co-1,4-cyclohexylene dimethylene terephthalate) Copolyesters

摘要

Poly(trimethylene terephthalate)(PTT) homopolymer and a series of Poly(trimethylene terephthalate co-1,4-cyclohexylene dimethylene terephthalate) Copolyesters (PTCT) having intrinsic viscosities of 0.55～0.88dl/g were synthesized by melt polycondensation and copolycondensation in the presence of metallic catalysts, with varying feed ratios of 1,3-propanediol(PDO) and 1,4-cyclohexane dimethanol(CHDM). Practically, the CHDM comonomer contents in the copolyesters were higher than those in the feeds. The effect of cyclohexane dimethylene structure on the thermal properties of the copolyesters were investigated using differential scanning calorimetry(DSC) and thermal gravimetric analysis(TGA). The experimental result indicated that the copolyesters have better thermal stability than PTT. The glass transition temperatures(Tg) and melting temperature(Tm) of the copolyesters were differently increased with an increase in the CT content. However, no melting temperature was observed in the copolyester with the CT molar fraction at about 35%-49%.