Preparation And Properties Of Double Modified Phenolic Resin/Butyl Rubber Damping Composite

The main chain of butyl rubber(IIR)contains much pendant methyl groups,so it not only has ? transition,but also has secondary transitions due to the rotation and conformational transition of the pendant methyl group,which makes the effective damping temperature region of IIR wider.IIR is an environmentally friendly material,which is not harmful to the human body and the environment,so it is often used in the field of damping material matrix.However,when the temperature is over 15°C,IIR has low damping factor and poor damping effect.Therefore,improving the damping factor of IIR at room temperature and above room temperature is an important direction for studying IIR.At present,the research on the modification of IIR damping factor and temperature range focuses on copolymerization modification,hybridization with small molecules and interpenetrating polymer network modification.Although these methods can effectively improve the damping factor of IIR,the complex preparation conditions and the high cost make the industrial production difficult.The blending modification technology is the most commonly used technology to effectively improve the IIR damping factor and temperature range,but most of the researches in this area focus on the blending of IIR with other rubber and plastic materials.The research on improving the damping performance of IIR by blending modified phenolic resin is lacking in the literatures.In this paper,the blending modification technology was used to improve the damping factor of IIR at room temperature and above room temperature by blending IIR with modified phenolic resin.The specific contents are as follows:(1)The excessive addition of filler makes the proportion of matrix decrease,which can affect the damping factor of the damping composite.Using 15 phr,25phr,35 phr and 45 phr kaolin to blend with IIR,and then selecting 35 phr kaolin,sericite(800mesh)and sericite(1250mesh)to blend with IIR,the damping composites were prepared by vulcanization at 170°C and 15 MPa for 23 minutes.The test analyses of the samples show that the damping effect with 35 phr kaolin is the best in the several samples.The effective damping temperature(tan??0.3)extends to 48.4°C with the bonding glue of 5.9%.The toughness,the tensile strength and the heat resistance of the damping composite with 35 phr kaolin are also improved.(2)BF was prepared by esterification and transesterification,and the gradient of the mass fraction of BF was designed with 8phr,18 phr,28phr,38 phr and 48 phr to blend with IIR.Under the conditions of 170°C and 15 MPa with vulcanized time of 23 min,the BF modification damping composites were prepared.The infrared spectrum,cross-sectional morphology,dynamic thermomechanical properties,mechanical properties and thermal weightlessness properties of the BF modification damping composite samples were tested.The results show that when BF is added,the molecular chains are entangled to form hydrogen bonds.Adding BF can improve the toughness and tensile strength of the damping composite materials.For 8phr,18 phr,28phr,38 phr and 48 phr BF,the effective damping temperatures(tan??0.3)respectively extend to 53.3°C,64.3°C,69.1°C,70.4°C and 72.5°C,and the tan? value is increased with the increasing of BF adding content.When 38 phr BF is added,the overall performance of BF modification damping composite is the best,and the quality retention rate at 800°C reaches 20.78%,improve heat resistance.(3)Using the same method to synthesize linseed oil modified phenolic resin(LOPF),and the gradient of the mass fraction of LOPF was designed with 8phr,18 phr,28phr,38 phr and 48 phr to blend with IIR.Under the conditions of 170°C and 15 MPa with vulcanized time of 23 min,the LOPF modification damping composites were prepared.The infrared spectrum,cross-sectional morphology,dynamic thermomechanical properties,mechanical properties and thermal weightlessness properties of the LOPF modification damping composite samples were tested.The results show that when LOPF is added,the molecular chains are entangled to form hydrogen bonds.For 8phr,18 phr,28phr,38 phr and 48 phr LOPF,the effective damping temperatures(tan??0.3)respectively extend to 43.5°C,46.4°C,47.9°C,48.6°C and 50.1°C,which are wider than that of pure IIR.The toughness of the LOPF modification damping composite is significantly improved.When 48 phr LOPF is added,the modification effect on damping factor is the best,and the mass retention rate at 800°C is 17.94%,and the toughness of the damping composite material is greatly improved.(4)Boron-linseed oil double modified phenolic resin(BLOPF)was synthesized by the same method,and the gradient of the mass fraction of BLOPF was designed with 8phr,18 phr,28phr,38 phr and 48 phr to blend with IIR.Under the conditions of 170°C and 15 MPa with vulcanized time of 23 min,the BLOPF modification damping composites were prepared.The infrared spectrum,cross-sectional morphology,dynamic thermomechanical properties,mechanical properties and thermal weightlessness properties of the BLOPF modification damping composite samples were tested.The results show that when BLOPF is added,the molecular chains are entangled to form hydrogen bonds,and the toughness and tensile strength of the BLOPF modification damping composite materials are improved.For 8phr,18 phr,28phr,38 phr and 48 phr BLOPF,the effective damping temperatures(tan??0.3)respectively extend to 47.1°C,51.1°C,61.4°C,65.8°C and 66.1°C.However,when 38 phr and 48 phr BLOPF are added,it can be seen from the graph of tan?-T that the lines are basically close.Therefore,it is concluded that the damping modification effect is better when BLOPF is added with 38 phr,and the mass retention rate at 800°C is 19.48%,at the same time make the toughness improved.