Poly(ethylene isophthalate)s: effect of the tert-butyl substituent on structure and properties

Quintana, Robert; Ilarduya, Antxon Martı́nez de; Rudé, E.; Kint, Darwin P. R.; Alla, Abdelilah; Galbis, Juan A.; Muñoz‐Guerra, Sebastián

doi:10.1016/j.polymer.2004.05.028

Cited by 8 publications

(5 citation statements)

References 20 publications

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“…The polyester PHT used as raw material for the production of c(HT) n cyclic oligomers was prepared by melt polycondensation of HD and DMT. This reaction was performed according to Quintana et al, 28 the resulting polyester being obtained in 84% yield with a weightaverage molecular weight of ≈63 000 and a polydispersity near 2. Details of reaction conditions and characteristics of the produced PHT are given in Table 1.…”

Section: Resultsmentioning

confidence: 99%

“…This polymer was synthesized to be used as source of cyclic oligomers of hexamethylene terephthalate. It was prepared by conventional polycondensation of HD and DMT according to a procedure described in the literature, 28 with minor modifications. HD (65.32 g, 0.453 mol) and DMT (40 g, 0.206 mol) in a feed molar ratio of 2.2:1 were introduced into a threenecked 100 mL round-bottom flask equipped with a mechanical stirrer, a nitrogen inlet, and a vacuum distillation outlet.…”

Section: Methodsmentioning

confidence: 99%

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Poly(hexamethylene terephthalate-co-caprolactone) Copolyesters Obtained by Ring-Opening Polymerization

et al. 2008

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A set of aromatic-aliphatic copolyesters were synthesized by ring-opening polymerization of hexamethylene terephthalate (HT) cyclic oligomers and -caprolactone monomer (CL) at 175 °C using Sb 2 O 3 catalyst. A hexamer-and heptamer-enriched cyclic fraction isolated from the product obtained in the cyclodepolymerization of poly(hexamethylene terephthalate) (PHT) was used. Ring-opening copolymerizations were conducted for HT to CL feed ratios covering the whole range of compositions and for increasing periods of reaction time. The comonomer contents of the resulting copolyesters were similar to those of their respective feeds, and did not vary with reaction time. In contrast, the copolyester microstructure evolved from block to random as the reaction progressed. The thermal properties of the copolyesters was apparently dependent on both composition and microstructure, and therefore changed with reaction time. The hydrolysis of the copolyesters in simulated physiological medium with and without addition of lipase was evaluated. Copolyesters containing more than 10% of CL were readily degraded in the presence of the enzyme. In contrast to PHT and other copolyesters with lower CL contents, the 50/50 copolyester also underwent extensive hydrolysis upon incubation at pH 10.2 and 80 °C.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Poly(hexamethylene terephthalate-co-caprolactone) Copolyesters Obtained by Ring-Opening Polymerization

et al. 2008

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“…It was prepared by polycondensation of CHDM and DMT according to the procedure described in the literature, [20] with minor modifications. CHDM (48.99 g, 0.34 mol) and DMT (30 g, 0.154 mol), that is, with a molar ratio of 2.2:1, were introduced into a 199 mL three-necked round-bottom flask equipped with a mechanical stirrer, a nitrogen inlet, and a vacuum distillation outlet.…”

Section: Synthesis Of Pct By Polycondensationmentioning

confidence: 99%

“…[12][13][14][15][16] The latter has become particularly useful for the preparation of alkylene phthalate cyclic oligomers from industrial thermoplastic polyesters like PET, [4,10,11,17] poly(butylene terephthalate), [18,19] and poly(ethylene isophthalate). [20] The procedure, which has been studied in detail by several authors, is based on the ring-chain equilibrium reaction that takes place by heating the polyester at high dilution affording cyclic oligomer fractions in good yields. As a consequence, ROP is starting to be considered a serious alternative to the traditional polycondensation method for the preparation of the most-extensively used aromatic polyesters.…”

Section: Introductionmentioning

confidence: 99%

Poly(ethylene‐co‐1,4‐cyclohexylenedimethylene terephthalate) copolyesters obtained by ring opening polymerization

González-Vidal

Ilarduya

Muñoz‐Guerra

2009

J. Polym. Sci. A Polym. Chem.

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Cyclic oligomer fractions of ethylene terephthalate c(ET)n and 1,4-cyclohexylenedimethylene terephthalate c(CT)n were obtained by yclodepolymerization of their respective polyesters, the former containing around 80 mol % of trimer and the latter with around 70 mol % of trimer to pentamer. Mixtures of these fractions at selected compositions were subjected to ring opening copolymerization to give a series of poly(ethylene-cocyclohexylenedimethylene terephthalate) copolyesters with ET/CT comonomer ratios ranging from 90/10 to 10/90. The copolyesters were characterized by GPC and NMR, and their thermal properties were evaluated by DSC and TGA. They had essentially the same composition as the feed from which they were produced and had an average-weight molecular weights between 30,000 and 40,000 g/mol with polydispersities between 2 and 2.7. The distribution of the monomeric units in these copolyesters was essentially at random although it evolved to be a blocky microstructure as the contents in the two comonomers became more dissimilar. Their thermal behavior was the expected one for these types of copolyesters with crystallinity and heating stability decreasing with the content in CT units.

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“…For diethyl isophthalate (DEI) as the diester, it seems that a higher reaction temperature leads to a better chain elongation, whereas applying a vacuum does not have any major influence on the oligomers. DEI is known to be a temperature-stable molecule (usually polymerized chemo-catalytically at 260 • C [25]) and all produced materials result in white-colored polymers (see Supplementary Materials Figure S1). Upgrade of the aliphatic oligoester PBA was the most successful in this study, since the weight-average molecular weight of the initial oligomers increased from 5400 Da to over 18,000 Da when conducting the upgrades under vacuum.…”

Section: Catalyst-free Thermal Upgrade Of the Enzymatically Synthesizmentioning

confidence: 99%

Thermal Upgrade of Enzymatically Synthesized Aliphatic and Aromatic Oligoesters

et al. 2020

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The enzymatic synthesis of polyesters in solventless systems is an environmentally friendly and sustainable method for synthetizing bio-derived materials. Despite the greenness of the technique, in most cases only short oligoesters are obtained, with limited practical applications or requiring further chemical processing for their elongation. In this work, we present a catalyst-free thermal upgrade of enzymatically synthesized oligoesters. Different aliphatic and aromatic oligoesters were synthesized using immobilized Candida antarctica lipase B (iCaLB) as the catalyst (70 • C, 24 h) yielding poly(1,4-butylene adipate) (PBA, M w = 2200), poly(1,4-butylene isophthalate) (PBI, M w = 1000), poly(1,4-butylene 2,5-furandicarboxylate) (PBF, M w = 600), and poly(1,4-butylene 2,4-pyridinedicarboxylate) (PBP, M w = 1000). These polyesters were successfully thermally treated to obtain an increase in M w of 8.5, 2.6, 3.3, and 2.7 folds, respectively. This investigation focused on the most successful upgrade, poly(1,4-butylene adipate), then discussed the possible effect of di-ester monomers as compared to di-acids in the thermally driven polycondensation. The herein-described two-step synthesis method represents a practical and cost-effective way to synthesize higher-molecular-weight polymers without the use of toxic metal catalysts such as titanium(IV) tert-butoxide, tin(II) 2-ethylhexanoate, and in particular, antimony(IV) oxide. At the same time, the method allows for the extension of the number of reuses of the biocatalyst by preventing its exposure to extreme denaturating conditions.

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Poly(ethylene isophthalate)s: effect of the tert-butyl substituent on structure and properties

Cited by 8 publications

References 20 publications

Poly(hexamethylene terephthalate-co-caprolactone) Copolyesters Obtained by Ring-Opening Polymerization

Poly(hexamethylene terephthalate-co-caprolactone) Copolyesters Obtained by Ring-Opening Polymerization

Poly(ethylene‐co‐1,4‐cyclohexylenedimethylene terephthalate) copolyesters obtained by ring opening polymerization

Thermal Upgrade of Enzymatically Synthesized Aliphatic and Aromatic Oligoesters

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