Incorporation of 1,4-cyclohexanedicarboxylic acid into poly(butylene terephthalate)-b-poly(tetramethylene glycol) to alter thermal properties without compromising tensile and elastic properties

Abstract

Incorporation of 1,4-cyclohexanedicarboxylic acid to partially replace terephthalic acid results in a thermoplastic elastomer with decreased melting temperature and increased thermal stability while tensile and elastic properties remain unchanged.

Polybutylene terephthalate modified with dimer acid methyl ester derived from fatty acid methyl esters and its use as a hot‐melt adhesive

“…Generally, PBT is reported to be a semicrystalline polymer with a T g of 40~60 C, T m of 220~230 C, and ΔH f of 145 J g −1. 28,33 This conclusion is also supported by the decreasing L n T(I)-B and increasing random sequences in the copolymers, determined from the 1 H NMR results. The T m values showed a similar trend to that of T g and was observed from the DSC curve upon further heating.…”

“…The increasing irregularity of copolymers by introduction of third monomer disrupts the formation of crystals is also reported. 28,33 This conclusion is also supported by the decreasing L n T(I)-B and increasing random sequences in the copolymers, determined from the 1 H NMR results. These copolymer materials could lower the applicable temperature for hot melt adhesives.…”

“…All samples had high molecular weights (M n ) in the range of 8.8 to 19.6 kg mol −1 , comparable to values in the literature and for commercial products. 28,32 With increasing DAME content in the polyester copolymer series, the obtained molar mass gradually increased. This behavior could have two explanations.…”

“…The DAME content was varied from 20 to 50 mol%, and DMT and DMI were used at ratios of 4:1 and 1:1 to tailor the mechanical and adhesive properties of the polyesters. 16,28,29 Values for monomer composition, the number average sequence length (L n ) and the degree of randomness (DR) for the copolyesters are listed in Table I and were calculated from the integration area (I) of NMR peaks (c1, c2, d1, and d2) using eq 1-3. A distillate was collected during the condensation reaction under atmospheric pressure and nitrogen purging at 180 C for 5 h. The distillate was mainly methanol, confirmed by GC/MS, and small quantity of BDO.…”

“…It is interesting to mention that methylene protons next to the oxygen atom of repeating ester groups [ Figure 1(c1, c2, d1, and d2)] are split due to the magnetically different environments for monomer sequences in copolymers. 16,28,29 Values for monomer composition, the number average sequence length (L n ) and the degree of randomness (DR) for the copolyesters are listed in Table I and were calculated from the integration area (I) of NMR peaks (c1, c2, d1, and d2) using eq 1-3. 16…”