1 e-Polymers 2009, no. 004 http://www.e-polymers.org ISSN 1618-7229 Thermal, mechanical and wettability properties of some branched polyetherurethane elastomers Stelian Vlad, 1 * Iuliana Spiridon, 1 Cristian Vasile Grigoras, 1 Mioara Drobota, 1 Alexandra Nistor 1 1 * “Petru Poni” Institute of Macromolecular Chemistry, 700487, Iasi, Romania; fax: 040232-211299; email: vladus@icmpp.ro (Received: 23 April, 2008; published: 31 January, 2009) Abstract: In this study three series of polyetherurethanes (PEU) based on Terathane ® (polytetramethyleneetherglycol - PTMEG, M n 1400) as polyol; isophorone diisocyanate (IPDI), 4,4’-methylene-bis-(cyclohexyl-isocyanate) (HMDI) and hexamethylene diisocyanate (HDI) as aliphatic diisocyanate components; 1,4- butanediol (BD) and glycerin (Gly) as chain extenders were synthesized. The glycerin as triol is responsible for the crosslinking structures. All polyether urethanes were synthesized by prepolymer method. The PTMEG was reacted with diisocyanate to realize a diisocyanate-terminated prepolymer, which in next step was extended with blend of the 1,4-butanediol (BD) and glycerin (Gly) in different proportion. The influence of the diisocyanate structure and chain extender functionality on the thermal, mechanical and wettability properties were the aim of this study. The physical, mechanical and wettability properties of these polymers were measured according to standard methods. All polymers were characterized by conventional characterization methods. Different methods of thermal analysis (TGA and DSC) were used for characterization. Wettability was estimated by determination of the dynamic contact angle. The structures were confirmed by FT- IR and H-NMR analysis. The results show that the thermal stability, mechanical and wettability properties of the final products are influenced by the diisocyanate and chain extenders nature. Keywords: polyetherurethane, diisocyanate, mechanical properties, dynamic contact angle, surface tension Introduction Polyurethanes chemistry is considered one of the most versatile chemistries for polymer materials. They can be easily prepared by a simple polyaddition reaction of polyol, isocyanate and chain extender. Due to the ability to adapt polyurethanes’ molecular structures to specific property requirements, different types of polyurethane can be synthesized and used in a variety of applications including elastomers [1-3], flexible and rigid foams [4-7], medical devices [8-10], adhesives and coatings [11-14]. Segmented polyurethanes (PU) are generally composed of polyether or polyester soft segments and urethane based hard segments along the polymer backbone giving rise to a microphase-separated morphology caused by the usual poor compatibility between both segments. The unique properties of these polymers are directly related to their two phase microstructure, in which the hard domains act as reinforcing filler and as a thermally reversible cross-link [15]. Polyurethanes are produced by the exothermic reaction of molecules containing two or more isocyanate groups with polyol molecules containing two or more hydroxyl groups. Relatively few basic isocyanates and a far broader range of polyols of