Study On The Rubber Sealing Materials With Low Temperature Resistance

There are huge differences in climate from north to south in China, the minimumtemperature of winter in part of north could up to subzero35℃. In order to ensure that theseal gland of wind driven generator be working order in long time, it is imperative todevelope the sealing materials with low temperature resistance. This paper choose polyetherMPU, NBR with low acrylonitrile content and GECO as base materials to prepare composites.First of all, we investigated the effect of the dosage of dicumyl peroxide (DCP) and plasticizer,the kind and dosage of co-agents, anti-schorchers and reinforcing agents on the processability,curing properties, mechanical properties, weather resistance, oil resistance and lowtemperature resistance of polyether MPU. Then we studied the effect of ratio on theperformance of polyether MPU/NBR and polyether MPU/GECO.The results indicate that polyether MPU can be used to prepare composite materials withgood balance between low temperature resistance and oil resistance. The Tg of cured rubbertested by dynamic thermomechanical analysis apparatus(DMA) can be as low as-40.5℃. Theozone resistance and mechanical properties are good, but compression set is slightly high. Theoptimized formula indicates that the optimum dosage of carbon black N660is40~60phr, theoptimum dosage of plasticizer TP95is5~15phr, the optimum dosage of DCP is2phr, theoptimum dosage of co-agent R153D is3.5phr, the optimum dosage of anti-scorcher ZJ701is0.2phr.With blending NBR, the compression set resistance and low temperature resistance ofpolyether MPU will be improved, but the ozone resistance will be reduced. When the ratio ofNBR is20%, tensile strength can be up to19.1MPa, compression set reduces from43.2%to36.1%, the Tg of cured rubber reduces from-36.5℃to-38.2℃, and there is no crack appearsafter ozone aging.The best ratio of NBR is30%or less.With blending GECO, the processability and compression set resistance of polyetherMPU will be improved but the mechanical properties, abrasion resistance, oil resistance andlow temperature resistance will be reduced. When the ratio of GECO is20%, compression setreduces from31.2%to25.1%and the Tg of cured rubber raises from-40.4℃to-36.5℃. Thebest ratio of GECO is20%or less.