Study On Aliphatic Polyurethane Elastomer

A series of aliphatic polyurethane elastomers based on isophorone diisocyanate(IPDI)were synthesized by one-step process.The effect of different catalysts,urea groups,different kinds of soft segments and the content of Trimethylolpropane(TMP)on the structure and property of polyurethane elastomer were measured and compared.The polyurethane elastomer/montmorillonite nanocomposites with high therm-al stability were synthesized successfully.With increase in the amount of TMP,the crosslinking density of polyurethane elast-omer increased,and the thermal properties and rigidity of polyurethane elastomers were also enhenced.The initial mechanical properties and physical properties after aging increased when the content of TMP was lower than 4�10-4 mol�g-1.The effect of different catalysts on the structure and properties of polyurethane elastomers was studied.The polyurethane elastomer synthesized by lead naphthenate(PUE-Pb)had the highest crosslinking density,hardness and aging property,but the elongation at break and tensile strength were the lowest.The degree of phase mixing between soft domains and hard domains in the polyurethane elastomer that synthesized by bismuth octoate(PUE-Bi)was low,but PUE-Bi sample had the highest elongation at break and tensile strength.Four kinds of polyurethane elastomer with different soft segments were prepared from polyether polyol and polyester polyol.The results showed that the polyurethane elastomers based on polyester had better thermal properties and aging properties than the polyurethane elastomer based on polyether.The polyurethane elastomer prepared from poly(neopentyl glycol adipate)diol had the highest thermal and aging properties.The polyurethane elastomers with urea groups were synthesized and characterized by adding ethanol amine as chain extender agent.The disorded hydrogen bonding of hydrogen bonding of urea groups in the polyurethane was mainly from,and the thermal stability of polyurethane elastomer was improved a little when the urea groups were introduced into the polyurethane.Finally,the polyurethane elastomer/montmorillonite nanocomposites were synthesized by in situs intercalative polymerization.The results showed that polyurethane/montmorill-onite intercalated composites were synthesized.The thermal stability,tensile strength,elongation at break and rigidity of polyurethane elastomer increased when the montmorillonit/polyurethane nanocomposites were formed.