Reactive processing of poly(ethylene terephthalate) modified with multifunctional epoxy-based additives

Japon, Sonia; Boogh, L.; Leterrier, Y.; Månson, J.‐A. E.

doi:10.1016/s0032-3861(99)00768-5

Cited by 125 publications

(107 citation statements)

References 12 publications

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“…The only report of gelation has been when the reaction is performed for a time greater than one hour [30]. This indicates that it is possible to prevent gelation from taking place in PLA because of the extremely low reactivity of the hydroxyl group with the epoxy group at temperatures relevant for PLA processing [24]. However, it should be noted that the reactivity of the hydroxyl group with the epoxy group is negligible, it is not completely absent, particularly if the reaction is performed for a sufficiently long time, or at elevated temperatures.…”

Section: Molecular Weightmentioning

confidence: 99%

“…In fact, model compounds studies have shown that no reaction occurs between the hydroxyl group and the epoxy group up to 220 °C. In contrast, rapid reaction always occurs between the carboxylic acid group and the epoxy group at temperatures lower than 200 °C [24]. The epoxy group clearly exhibits different reactivity with the functional groups present at the two ends of a degraded PLA chain.…”

Section: Introductionmentioning

confidence: 98%

“…In an epoxy-polyester blend, it has been shown that the glycidyl to carboxyl end group esterification reaction precedes the slower glycidyl to hydroxyl group etherification reaction. The reactions of glycidyl to secondary hydroxyl etherification and the transesterification of primary and secondary hydroxyl chain ends onto polyester chains are slower reactions than the corresponding primary reactions [21,24]. In fact, model compounds studies have shown that no reaction occurs between the hydroxyl group and the epoxy group up to 220 °C.…”

Section: Introductionmentioning

confidence: 99%

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Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

et al. 2014

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Abstract:In order to reduce the effects of hydrolytic degradation and to maintain sufficient viscosity during processing of biomass based poly(L-lactic acid) (PLLA), various epoxy functional reactive oligomers have been characterized and incorporated into the degraded fragments as chain extenders. The molecular weight of PLLA increased with the increase in functionality of the reactive oligomers. No further increase in molecular weight was observed for oligomers with functionality of greater than five. Under our experimental conditions, no gelation was found even when the highest functionality reactive oligomers were used. This is attributed to the preferential reaction of the carboxylic acid versus the negligible reactivity of the hydroxyl groups, present at the two ends of the degraded PLLA chains, with the epoxy groups. The study provides a clear understanding of the degradation and chain extension reaction of poly(lactic acid) (PLA) with epoxy functional reactive oligomers. It is also shown that a higher functionality and concentration of the reactive oligomers is needed, to bring about a sufficient increase in the molecular weight and hence the hydrolytic stability in circumstances when PLA chains suffer significant degradation during processing.

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Section: Molecular Weightmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

et al. 2014

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“…Moreover, by the contrast to the commonly used thermoplastic resins, attention was paid to recycled materials [4,5]. In order to increase the polymer viscosity and to enhance the foamability of recycled PET, various techniques have been investigated, including chain extension by reactive extrusion [4][5][6][7][8][9][10]. The results obtained with this technique are encouraging since it allows to perform in a single step the rheological upgrading of recycled polymer and foaming process.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and experimental study of foaming process with chain extended recycled PET

Coccorullo¹,

Maio²,

Montesano³

et al. 2009

Express Polym. Lett.

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Abstract. The theoretical and experimental study of a thermoplastic polymer foaming process is presented. Industrial scraps of PET were used for the production of foamed sheets. The process was performed by making use of a chemical blowing agent (CBA) in the extrusion process. Due to the low intrinsic viscosity of the recycled PET, a chain extender was also used in order to increase the molecular weight of the polymer matrix. Pyromellitic dianhydride (PMDA) and Hydrocerol CT 534 were chosen as chain extender and CBA, respectively. The reactive extrusion and foaming were performed in a two step process. Rheological characterization was carried out on PET samples previously treated with PMDA, as well as the morphological study was performed to define the cellular structure of the foams produced. Moreover, in order to predict the morphology of the foam, a non isothermal model was developed by taking into account both mass transfer phenomenon and viscous forces effect. Model results were compared with experimental data obtained analyzing the foamed samples. The model was validated in relation to working conditions, chemical blowing agent percentage and initial rheological properties of recycled polymer. A pretty good agreement between experimental and calculated data was achieved.

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“…These technologies show essential advantages compared with the solid-state polycondensation. These alternative technologies are mostly based on chemical transformations of macromolecules in molten polyesters; such chemical transformations occur with the help of additional bi-or multi-functional chemicals capable of extending the chain (so-called chain extenders) [10][11][12][13][14][15]. The chain extenders (CE) interact in melt mostly with terminal functional groups of polyester macromolecules and link them with one another; so the molecular weight does decrease, it rather increases to some extent.…”

Section: Introductionmentioning

confidence: 99%

Structural features and relaxation properties of PET/PC blends containing impact strength modifier and chain extender

Песецкий¹,

Filimonov²,

Koval³

et al. 2009

Express Polym. Lett.

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Abstract. It has been investigated how methylene diphenyl diisocyanate (MDI) influences the morphology, rheological, mechanical and relaxation properties, as well as PET crystallizability, of PET/PC/(PP/EPDM) ternary blends produced by the reactive extrusion process. It appears that irrespective of phase structure of the blends, MDI causes a rise in melt viscosity (decreased MFI-values) of the material which is the result of an increased molecular weight of the macromolecules; PET crystallization becomes retarded. MDI improves compatibility between PET and PC in PET/PC/(PP/EPDM) ternary blends. Addition of MDI leads to higher values of the dynamic shear modulus for PET high elastic state (in the temperature range between Tg PET and cool crystallization temperature of PET); the PET cool crystallization and melt crystallization processes become retarded; the PET and PC glass transition temperatures approach one another. MDI has been shown not to influence significantly the blend morphology or the character of interaction between the PP/EPDM disperse phase and PET/PC blend matrix.

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Reactive processing of poly(ethylene terephthalate) modified with multifunctional epoxy-based additives

Cited by 125 publications

References 12 publications

Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

Theoretical and experimental study of foaming process with chain extended recycled PET

Structural features and relaxation properties of PET/PC blends containing impact strength modifier and chain extender

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