Lightweight tire support and composition and method for making a tire support

A lightweight tire support, said tire support comprising:

• (A) a hard-segment polymer comprising a reaction product of an at least one first isocyanate and an at least one chain extender;
• (B) a soft-segment polymer comprising a reaction product of an at least one second isocyanate and an at least one polyol, said at least one second isocyanate being the same as or different from said at least one first isocyanate;
• and
• (C) said hard-segment polymer and said soft-segment polymer being present in an amount effective for providing said tire support with load-bearing capability and temperature stability.

A polyurethane-polymer composition suitable for preparing a lightweight tire support, said composition comprising:

• (A) at least two polyols comprising a first polyol and a second polyol, said first polyol comprising a polypropylene oxide and said second polyol comprising an ethylene oxide-capped polyol;
• (B) at least one chain extender comprising at least one of an aliphatic amine chain extender, an aromatic amine chain extender, and a modified amine chain extender;
• and
• (C) at least one isocyanate comprising at least one of 4,4′-, 2,4′-, and 2,2′-diphenylmethanediisocyanate, said at least one isocyanate being present in an amount effective to react with said at least one chain extender to provide a hard-segment polymer in an amount of at least 25 weight percent and no greater than 45 weight percent based on the total weight of said composition,
• wherein a tire support prepared from said composition has a weight of no greater than 8 kg, a tensile modulus of at least 30 mPa at 80° C. and no greater than 50 mPa at 80° C. as determined by ASTM D638, and a change in tensile modulus of no more than 15 percent over a temperature range of −50° C. to 150° C. based on dynamic mechanical spectroscopy.

A method of preparing a lightweight tire support, said method comprising:

• (A) injecting an isocyanate-side stream into a processing mold designed to mold a tire support, said isocyanate-side stream comprising at least one isocyanate;
• (B) injecting a polyol-side stream into said processing mold, said polyol-side stream comprising at least one polyol and at least one chain extender;
• and
• (C) reacting said isocyanate-side stream and said polyol-side stream in said processing mold to form a tire support, said tire support comprising a hard-segment polymer and a soft-segment polymer, said soft-segment polymer and said hard-segment polymer being present in an amount effective for providing said tire support with temperature stability and load-bearing capability.