The effect of metal catalysts in promoting the formation of the comb copolymer between a very lowdensity polyethylene (VLDPE) grafted with diethyl maleate and PET has been studied in this paper following a model study based on low molecular weight molecules resembling the local structure of the reactive groups in the reference macromolecules. Ti(OBu)4 was used as the catalyst and the reactions were carried out under the same conditions as in the case of the macromolecules species. The model mixtures have been analyzed by FT-IR, 1Hand 13CNMRspectroscopy, thermogravimetric analysis (TGA) and GC-MS and evidence of the degradation of ester bonds, deactivation of hydroxyl terminals of PET and the possible crosslinking of functionalized polyolefin have been observed. The molecular model process agrees with results obtained for the macromolecular system blending PET and VLDPE grafted with diethyl maleate in a Brabender mixer in the presence of Ti(OBu)4, as evaluated by mixer torque values and selective extraction results. Therefore, the present model study allows us to both obtain information about reaction mechanism in the complex melt biphasic system and to suggest new strategies to optimize the process
A model study of Ti(OBu)4 catalyzed reactions during reactive blending of polyethylene (PE) and poly(ethylene terephthalate)
COLTELLI, MARIA BEATRICE;SAVI, STEFANIA;LIUZZO, VINCENZO;AGLIETTO, MAURO;CIARDELLI, FRANCESCO
2004-01-01
Abstract
The effect of metal catalysts in promoting the formation of the comb copolymer between a very lowdensity polyethylene (VLDPE) grafted with diethyl maleate and PET has been studied in this paper following a model study based on low molecular weight molecules resembling the local structure of the reactive groups in the reference macromolecules. Ti(OBu)4 was used as the catalyst and the reactions were carried out under the same conditions as in the case of the macromolecules species. The model mixtures have been analyzed by FT-IR, 1Hand 13CNMRspectroscopy, thermogravimetric analysis (TGA) and GC-MS and evidence of the degradation of ester bonds, deactivation of hydroxyl terminals of PET and the possible crosslinking of functionalized polyolefin have been observed. The molecular model process agrees with results obtained for the macromolecular system blending PET and VLDPE grafted with diethyl maleate in a Brabender mixer in the presence of Ti(OBu)4, as evaluated by mixer torque values and selective extraction results. Therefore, the present model study allows us to both obtain information about reaction mechanism in the complex melt biphasic system and to suggest new strategies to optimize the processI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
