TAILIEUCHUNG - Báo cáo " AMPHIPHILIC POLYURETHANES WITH A NOVEL PEGCONTAINING CHAIN EXTENDER "

Polyurethanes are block copolymers composed of alternating short hard segments and long flexible soft segments that are thermodynamically incompatible at the temperature of use [1,2]. Phase separation of segmented polyurethanes (SPU) with a limited hard segment content results in hard segment rich domains dispersed in a continuous matrix of the soft segments [3]. The hard domains act as physical crosslink providing the polymer with mechanical strength while the soft matrix contributes to the elastomeric properties [4,5] | VNU. journal of science Nat. Sci. Tech. No1 2007 AMPHIPHILIC POLYURETHANES WITH A NOVEL PEGCONTAINING CHAIN EXTENDER PART I SYNTHESIS AND CHARACTERIZATION Pham Ngoc Lan 1 Luu Van Boi 2 Polymer Research Center Hanoi University of Technology 2 Department of Chemistry College of Science VNU 1. Introduction Polyurethanes are block copolymers composed of alternating short hard segments and long flexible soft segments that are thermodynamically incompatible at the temperature of use 1 2 . Phase separation of segmented polyurethanes SPU with a limited hard segment content results in hard segment rich domains dispersed in a continuous matrix of the soft segments 3 . The hard domains act as physical crosslink providing the polymer with mechanical strength while the soft matrix contributes to the elastomeric properties 4 5 . The main factors influencing the hard domain cohesion and the resulting phase separation include hydrogen bonding and crystallization 4 . Several strategies have been proposed to further improve the surface properties for polyurethanes 5 . In this respect polyethylene oxide rich surfaces that non selectively repel proteins and cells have been prepared and evaluated 6 7 . In the present work a novel PEG-containing chain extender was synthesized and the potential use of this chain extender for the synthesis of segmented polyurethanes was investigated. Thus a series of amphiphilic copolymers with PEG side chains of different MW were prepared. This article described the synthesis and chemical characterization of both the novel chain extender and the resultant grafted polyurethanes. 2. Experimental . Materials All solvents were used as received except for pyridine dried on CaH2 and dichloromethane dried on P2O5 . Poly THF-CD a special polyether polycarbonate diol with MW 2000 and based on Poly THF was obtained from BASF. The a-hydroxy-ffl-methoxypolyethylene glycols MPEG were obtained from Jansen MW350 Acros MW550 750 1000 and Polymer Laboratories

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