Studies of the hydrolytic stability of poly(urethane–urea) elastomers synthesized from oligocarbonate diols

• Published in: Polymer degradation and stability Vol. 95; no. 12; pp. 2413 - 2420
• Main Authors: Kozakiewicz, Janusz, Rokicki, Gabriel, Przybylski, Jarosław, Sylwestrzak, Krystyna, Parzuchowski, Paweł G., Tomczyk, Karolina M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2010; Elsevier
• Subjects: 1,6-Hexanediol; Applied sciences; Biological and medical sciences; Carbonates; Dimethyl; Dimethyl carbonate; Diols; Elastomers; Ethylene; Ethylene carbonate; Exact sciences and technology; Hydrolysis; Immersion; Mechanical properties; Medical sciences; Oligocarbonate diols; Organic polymers; Physicochemistry of polymers; Poly(carbonate–urethane)s; Poly(carbonate–urethane–urea)s; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; Stability; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; 1,6-Hexanediol; Ethylene carbonate; Dimethyl carbonate; Poly(carbonate–urethane)s; Oligocarbonate diols; Poly(carbonate–urethane–urea)s; Biological properties; Mechanical properties; Thermoplastic rubber; Tensile property; Urea copolymer; Experimental study; Urethane copolymer; Polyaddition; Polyurethane elastomer; Poly(carbonate—urethane—urea)s; Hydrolysis; Hydrolysis resistance; Poly(carbonate-urethane)s; Preparation; Surface properties; Carbonate copolymer; Biomaterial; Property structure relationship; Chemical properties
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2010.08.017

Polyurethane and poly(urethane–urea) elastomers synthesized from oligocarbonate diols are characterized by very good mechanical properties, biocompatibility and excellent resistance to both oxidation and hydrolysis and therefore are widely used in medical applications. In this paper the results of studies on hydrolytic stability of poly(urethane–urea) elastomers (PURC) obtained by moisture-curing of corresponding urethane prepolymers synthesized from isophorone diisocyanate (IPDI) and four different oligocarbonate diols (OCD) are presented. OCD were synthesized from dimethyl carbonate and 1,6-hexanediol, from cyclic ethylene carbonate and 1,6-hexanediol as well as from trimethylene carbonate. The changes of the sample weight, mechanical properties and surface properties after immersion in a standard phosphate buffer solution (pH
=
7.4) for up to 3 months at 70
°C were monitored. It was shown that neither sample weight nor mechanical properties changed significantly for PURC obtained from OCDs synthesized from 1,6-hexanediol and dimethyl carbonate or ethylene carbonate what confirms good resistance to hydrolysis of those PURC. Also SEM studies of those samples before and after immersion did not reveal any surface degradation effects. However, PURC sample obtained from OCD synthesized from trimethylene carbonate showed significant changes in mechanical properties and distinct change of appearance and surface erosion after 3 months immersion. The initial decrease and later increase of stress at break observed for PURC samples during immersion, was explained by the reaction of residual NCO groups present in PURC with water leading to molecular weight increase which proceeded during immersion period in parallel to hydrolysis of carbonate bond.