Synthesis and Thermal Analysis of Branched and "Kinked" Poly (ethylene terephthalate)

Jayakannan, M and Ramakrishnan, S (1998) Synthesis and Thermal Analysis of Branched and "Kinked" Poly (ethylene terephthalate). In: Journal of Polymer Science Part A : Polymer Chemistry, 36 (2). pp. 309-317.

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Abstract

Poly(ethylene terephthalate) (PET) was synthesized by self-condensation of bis-(2-hydroxyethyl) terephthalate (BHET). Copolymerization of BHET with ethyl, bis-3,5-(2- hydroxyethoxy) benzoate (EBHEB) and ethyl, 3-(2-hydroxyethoxy) benzoate (E3HEB) yielded copolymers that ontain varying amounts of branching and kinks, respectively. Copolymers of BHET with ethyl, 4-(2-hydroxyethoxy) benzoate (E4HEB), in which only the backbone symmetry is broken but without disruption of the linearity, were also prepared for comparison. The composition of the copolymers were established from their $^1H-NMR$ spectra. The intrinsic viscosity of all the copolymers indicated that they were of reasonably high molecular weights. The thermal analysis of the copolymers using DSC showed that both the melting temperatures $(T_m)$ and the percent crystallinity (as seen from the enthalpies of melting $(\Delta H_m)$ decreased with increasing comonomer (defect concentration) content, although their glass transition temperatures $(T_g)$ were less affected. This effect was found to be most pronounced in the case of branching, while the effects of kinks and linear disruptions, on both $T_m$ and $\Delta H_m$, were found to be similar.

Item Type:	Journal Article
Publication:	Journal of Polymer Science Part A : Polymer Chemistry
Publisher:	Wiley
Additional Information:	Copyright of this article belongs to Wiley.
Keywords:	Thermal analysis;Branched poly(ethylene terephthalate)
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	08 Jan 2007
Last Modified:	19 Sep 2010 04:33
URI:	http://eprints.iisc.ac.in/id/eprint/9371

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