Mechanical properties of polyurethane-unsaturated polyester interpenetrating polymer networks

0032-3888

Chemistry ; Chemical Engineering

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Interpenetrating polymer networks (IPNs) based on a polyurethane (PU) and two unsaturated polyester (UPE) resins (a commercially available UPE and a partially endcapped UPE) were prepared. The mechanical properties, such as tensile strength, elongation at break, impact strength, and dynamic mechnical properties of IPNs, were studied by changing reaction temperature, PU reaction rate, and UPE reaction rate. Owing to the unique microgel formaton of UPE, the first formed network tends t be the dispersed phase in the PU-UPE IPN system. The reaction sequence was found to be an important factor in determining the phase mixing and phase morphology of the IPNs. When the PU reaction was faster, extensive phase mixing due to strong grafting or chain interpenetration was obtained. When the UPE reacted first, grafting was retarded by the microgel formation of the UPE network. It was found that simultaneous reaction of the two reacting system resulted in a co-continuous structure that provided enhanced tensile properties and impact strength.

15 Ill.

Electronic Resource