Synthesis of surface-modifying macromolecules for use in segmented polyurethanes

Abstract

SYNOPSISPolyurethanes are one of the most important classes of thermoplastic elastomers and have been widely used in medical-device manufacturing as well as in other applications. However, their function can be limited, particularly under environmental conditions that render them susceptible to hydrolysis. Using polymeric additives that are hydrolytically stable may be one approach to modifying the surface of polyurethanes for the purpose of improving their hydrolytic resistance without compromising their structural features. In this paper, the development of a series of novel fluorine-containing polyurethane surface modifying macromolecules (SMMs) is described and their synthesis conditions are investigated. The material structure and mixing properties of the synthesized SMMs with base polyurethanes was dependent on the reactant stoichiometry and concentration for the SMM components, as well as the reaction temperature and the amount of catalyst used in the SMM synthesis.This study describes the use of low surface energy components (fluorinated tails) which showed selective migration towards the surface when added to a polyester-urea-urethane. These novel macromolecules generated a nonwettable surface while not significantly altering the apparent bulk structure of the base polymer. The advancing and receding contact angle results indicated that the surface of these modified polyurethanes showed wettability characteristics similar to that of Teflon.TM The differential scanning calorimetry thermograms for the mixtures of the SMM with the polyurethane showed that, a t 5% w/w SMM in the base polyurethane, the thermal transitions were similar to that of the native base polyurethane, indicating that the additives had no detectable effect on the polyurethane structure.

Generation of cell adhesive substrates using peptide fluoralkyl surface modifiers

“…2 Lysine diisocyanate was distilled under vacuum stored in sealed ampoules and used within three months. The fluoroalcohol was distilled as described elsewhere [6] and degassed under vacuum at 40 1C prior to synthesis. A reactant ratio of 2:1:2 (diisocyanate/PTMO diol/fluoroalcohol) was used, and the reaction was catalyzed using dibutyl tin dilaurate (DBTDL).…”

“…To determine the effect of fluorine in the absence of the bioactive peptide on cellular interactions with PCNU surfaces, a nonbioactive SMM, synthesized with HDI, PTMO, and fluoroalcohol in a 2:1:2 ratio, was used in this study. This material will be referred to as an SMM, and was synthesized in-house using previously reported techniques [6].…”

“…It has been shown that low molecular weight polyurethane oligomers, end-capped with fluorinated groups, and termed surface modifying macromolecules (SMMs), when blended with polyurethane and other polymers, selectively migrate to the surface, and form fluorine rich interfaces [6]. The oligomeric backbone of the SMM is chemically tailored to be compatible with the bulk polymer, so that the SMM can form strong stable interactions with the bulk polymer without compromising the mechanical properties of the device.…”

Synthesis and properties of UV-curable polyurethane acrylates containing fluorinated acrylic monomer/vinyltrimethoxysilane

“…These materials combine some of the virtues of polyurethane and fluorinated acrylate/acrylate polymer, such as high thermal stability, good chemical resistance, low water absorptivity (water resistance), attractive surface properties, excellent flexibility, good wearability and high weatherability [12,[36][37][38][39][40].…”

Synthesis and properties of novel fluorinated aliphatic polyurethanes with fluoro chain extenders

“…Santerre et al [20,21] mixed fluorine-containing polyurethanes, used as surface-modifying macromolecules, with base polyurethanes to alter the surface chemistry of the base polyurethanes, thereby altering their biostability and/or biocompatibility. Tonelli et al [16] showed that fluorinated polyurethanes with different fluorine content are not thrombogenic and not cytotoxic.…”