Polyurethane

Abstract

A polyurethane that is a reaction product of reaction components, the reaction components comprising (a) a polyol; (b) a polyisocyanate selected from an aromatic, alicyclic or aliphatic polyisocyanate or combinations thereof; (c) a mixture of chain extenders that includes (i) a chain extender having a sulfur bridge in an amount of between 1 and 30 weight percent of the total mixture of claim extenders and (ii) a main chain extender, wherein the chain extender having a sulfur bridge. The chain extender having a sulfur bridge may be characterized as R 1 -A-S x —B—R 2 wherein R 1 and R 2 are selected from an OH, an NH 2 or combinations thereof, A and B are selected from a divalent aliphatic, alicyclic or aromatic organic group or combinations thereof, A and B may be the same or different and x is an integer of between 2 and 10.

What is claimed is: 
     
         1 . A polyurethane that is a reaction product of reaction components, the reaction components comprising:
 (a) a polyol;   (b) a polyisocyanate selected from an aromatic, alicyclic or aliphatic polyisocyanate or combinations thereof;   (c) a mixture of chain extenders that includes (i) a chain extender having a sulfur bridge in an amount of between 1 and 30 weight percent of the total mixture of claim extenders and (ii) a main chain extender, wherein the chain extender having a sulfur bridge is characterized as
   R 1 -A-S x —B—R 2  
 
   
       wherein R 1  and R 2  are selected from an OH, an NH 2  or combinations thereof, wherein A and B are selected from a divalent aliphatic, alicyclic or aromatic organic group or combinations thereof, wherein A and B may be the same or different and wherein x is an integer of between 2 and 10; and
 (d) an enhancer selected from free sulfur, a rubber curing accelerator or combinations thereof. 
 
     
     
         2 . The polyurethane of  claim 1 , wherein the enhancer is the rubber curing accelerator. 
     
     
         3 . The polyurethane of  claim 2 , wherein the rubber curing accelerator is diphenyl guanidine. 
     
     
         4 . The polyurethane of  claim 2 , wherein the reaction components comprise between 90 and 110 mole percent of the sulfur bridge chain extender moles. 
     
     
         5 . The polyurethane of  claim 2 , wherein the reaction components comprise between 0.5 and 10 weight percent of the polyol. 
     
     
         6 . The polyurethane of  claim 1 , wherein the enhancer is the free sulfur. 
     
     
         7 . The polyurethane of  claim 1 , wherein the main chain extender carries no cationic group. 
     
     
         8 . The polyurethane of  claim 1 , wherein the main chain extender is a short-chained chain extender. 
     
     
         9 . The polyurethane of  claim 1 , wherein the main chain extender is selected from 1,2, ethanediol, 1,2 propanediol, 1,2 butanediol, ethylene diamine, 1,2 propane diamine, propylene diamine, propylenediol, 4,4′-methylene bis-(3-chloro-2,6-diethylaniline) (MCDEA), 4,4′-methylene bis(2-chloroaniline) (MOCA), diethylthiotoluenediamine (DETDA) and dimethylthiotoluenediamine (DMTDA) or combinations thereof. 
     
     
         10 . The polyurethane of  claim 1 , wherein the main chain extender is selected from a dialcohol, a diamine or combinations thereof. 
     
     
         11 . The polyurethane of  claim 1 , wherein the mixture of chain extenders includes the chain extender having a sulfur bridge in an amount of between 2 and 25 weight percent of the total mixture of claim extenders. 
     
     
         12 . The polyurethane of  claim 1 , wherein the mixture of chain extenders includes the chain extender having a sulfur bridge in an amount of between 5 and 15 weight percent of the total mixture of claim extenders. 
     
     
         13 . The polyurethane of  claim 1 , wherein the polyisocyanate is a diisocyanate. 
     
     
         14 . The polyurethane of  claim 1 , wherein the chain extender having a sulfur bridge is selected from 2,2 dithiodiethanol, 4,4-dithiodianiline or combinations thereof. 
     
     
         15 . The polyurethane of  claim 1 , wherein x is an integer between 2 and 5. 
     
     
         16 . The polyurethane of  claim 1 , wherein the polyurethane is moldable. 
     
     
         17 . An apparatus, comprising:
 the polyurethane of  claim 1  disposed on at least one surface of a metal substrate.   
     
     
         18 . The apparatus of  claim 17 , wherein the polyurethane is of  claim 2 . 
     
     
         19 . The apparatus of  claim 18 , wherein the metal substrate is a metal reinforcement element. 
     
     
         20 . The apparatus of  claim 17 , wherein the metal substrate is a metal reinforcement element. 
     
     
         21 . The apparatus of  claim 17 , wherein the apparatus is a conduit, wherein one or more walls of the conduit comprise the polyurethane elastomer of  claim 1  and the one or more walls are reinforced with the metal substrate embedded therein. 
     
     
         22 . The apparatus of  claim 17 , wherein the apparatus is a conveyer belt. 
     
     
         23 . The apparatus of  claim 17 , wherein the apparatus is a caster.