Crystallization of 2‐methyl‐1,3‐propanediol substituted poly(ethylene terephthalate). I. Thermal behavior and isothermal crystallization

Abstract

Differential scanning calorimetry (DSC) was used to evaluate the thermal behavior and isothermal crystallization kinetics of poly(ethylene terephthalate) (PET) copolymers containing 2-methyl-1,3-propanediol as a comonomer unit. The addition of comonomer reduces the melting temperature and decreases the range between the glass transition and melting point. The rate of crystallization is also decreased with the addition of this comonomer. In this case it appears that the more flexible glycol group does not significantly increase crystallization rates by promoting chain folding during crystallization, as has been suggested for some other glycol-modified PET copolyesters. The melting behavior following isothermal crystallization was examined using a Hoffman-Weeks approach, showing very good linearity for all copolymers tested, and predicted an equilibrium melting temperature (T m 0 ) of 280.0°C for PET homopolymer, in agreement with literature values. The remaining copolymers showed a marked decrease in T m 0 with increasing copolymer composition. The results of this study support the claim that these comonomers are excluded from the polymer crystal during growth.

Isothermal crystallization of high density polyethylene and nanoscale calcium carbonate composites

“…A sample with higher crystallization temperature requires a longer time to complete crystallization. Relative crystallinity (X t ) was calculated as the ratio of the exothermic peak areas at time t and infinite time [14][15][16][17] :…”

Synthesis and characterization of novel poly(butylene succinate-co-2-methyl-1,3-propylene succinate)s

“…It is well recognized that the linearity and conformation of polymer backbone have a significant effect on the crystallization behavior of the polymer. The methyl group which MPD introduces into the polymer side chain helps to inhibit the crystallization of polyester resins [35][36][37][38][39]. The effects of MPD monomer on the physical properties of unsaturated [40][41][42][43] and isophthalate-based polyesters have been studied [44].…”

Thermal properties and chemical changes in blend melt spinning of cellulose acetate butyrate and a novel cationic dyeable copolyester

“…The dye uptake value of MCDP fiber is obviously higher than CDP fiber with the same SIP content. It might be explained that the crystallizability of polyester molecular chains was inhibited by the introduction of MPD, 6 which leads to the dyestuff molecular can be easily diffused into the MCDP molecular chains and combined with the SIP group. The dye uptake value of blend fibers was slightly decreased as CAB content increased, but was still close to the MCDP fiber, suggesting that the dyeability of blend fibers was also very good.…”

“…Therefore, we synthesized a novel cationic dyeable copolyester (MCDP) by adding 2‐methyl‐1,3‐propanediol (MPD) into sulfonate‐containing PET. MPD, as a smallest branched aliphatic diol, can reduce the crystallizability of modified polyester effectively 6. Shwartz and coworkers7 revealed that the modified polyester containing MPD has well spinnability and commercial values.…”