Synthesis and evaluation of mechanical and thermal properties of segmented condensation polyurethanes

Abstract

Condensation polyurethanes with different hard segment (HS) content were prepared by condensation reaction of urea, phenol sulphonic acid and formaldehyde and tested for their mechanical, physical and thermal properties. Obtained polyurethane (PUR) films were first heated at 50uC for 120 min and then treated at 135uC for 15 min or 160uC for 10 min. The tensile strength of samples thermally treated at 50uC then at 135uC was 120% higher than for samples treated only at 50uC. The obtained polyurethanes exhibited segmented structures with phase separation between HSs and soft segments (SSs). Films containing 19 and 21%HSs heated at 50uC then 135uC exhibited acceptable mechanical properties and water resistance. The lower and higher end use temperatures of PUR films were affected mainly by the polymer composition. Moreover, the polyurethane samples containing 19 and 21%HSs have shown the highest decomposition temperature (i.e. .165uC), compared to 80uC for polymers with 32%HSs.

Effect of the Additive Fire Retardants on the Properties of Rigid Polyurethane Foams, Obtained Using Hydroxyethyl Derivatives of Oxamide and Polymeric 4,4′-diphenylmethane Diisocyanate

“…Due to their versatile structure, polyurethane-based materials are used in various application fields [1][2][3]. The foamed materials are produced in quantity, both as rigid and elastic foams.…”

Thermal and mechanical properties of polyurethanes modified with L-ascorbic acid

“…Hard segments, derived from diisocyanates and low molecular weight chain extenders, possess high glass transitions. On the other hand, soft segments formed by polyols have low glass transitions [1][2][3][4][5]. Polyurethanes are commonly used medical devices such as catheters, wound dressings, drug delivery systems, artificial heart valves, vascular grafts, nerve implants, and tissue scaffolds [6].…”

Polyurethane foams modified with bisoxamidoester groups

“…The foamed polyurethane materials, obtained using hydroxyethyl and hydroxypropyl derivatives with oxamidoester groups, show increased compression strength (0.5 MPa) as compared to classic foams (r M = 0.1-0.2 MPa). Nevertheless, their compressive strength is not as high as that of condensation polyurethanes with different hard segments [31]. Generally the foams obtained using EC polyols exhibit slightly higher compression strength before temperature exposition.…”