Study On The Dynamic Mechanical Properties Of Polyurethane Elastomers

Polyurethane elastomers (PUE) is synthetic polymer materials which has manyexcellent comprehensive properties. Its many outstanding properties are better thanmany other materials’. For example, the high-abrasion resistance, tear resistance,excellent solvent resistance and so on. But the dynamic performance of PUE is poorbecause under dynamic conditions its internal heat is serious which attributes to thestrong intermolecular force of PUE. If used in high frequency oscillation or hightemperature environment, the dimensions of PUE will change and its strength,hardness, modulus will significantly decline resulting in the loss of its applicationvalue. In this article, the molecular structure of PUE had been changed to improve itsdynamic mechanical properties. The concrete methods are listed below.First of all, polyurethane elastomer was prepared via the prepolymer method. Inthis synthesis process, we used PTMEG and HTPB as polymer polyol and DADMT aschain extender. The results showed that the mechanical properties of PUE were thebest (Tensile strength was30.3MPa,Tear strength was99.8kN·m-1)when the mass ratioof HTPB and PTMEG was1:4. The dynamic performance of HTPB-based PUE wasbetter than the PTMEG-based. HTPB-based PUE had a higher thermal stability, butlower solvent resistance.Next, in the prepolymer preparation process, TMP was introduced into theHTPB-based PUE as polyol which could increase chemical crosslinking, and improvethe comprehensive properties of HTPB-based PUE via increasing perfect cross-linked structure. The results showed that, when the TMP content was5%, the mechanicalproperties of PUE (Tensile strength was16.9MPa, Tear strength was73.5kN·m-1) werebetter than pure HTPB-based PUE. The internal friction peak temperature decreased9.1℃, which showed the dynamic performance had been improved.The thermaldecomposition temperature increased15℃, so the heat resistance property had beenraised.Finally, in the prepolymer method, the organosilicon structure was introduced tothe PUE molecule. The results showed that polyester polyol218and PTMEG basedPUE had excellent mechanical properties (Tensile strength was44.8MPa, Tear strengthwas95.7kN·m-1). When the organosilicon content was5%, the internal friction peaktemperature decreased9.1℃, the dynamic performance had been improved. Thethermal decomposition temperature increased5℃, so the heat resistance had beenincreased. When the organosilicon content was10%,the solvent resistance was best.