Study On The Structure And Properties Of Modified Boron Nitride Nanosheet/rubber Composites

Rubber materials with thermal conductivity and mechanical strength have broad application in industry.In order to improve the thermal conductivity and physical properties of rubber,boron nitride nanosheets（BNNS）as well as the combination of boron nitride nanosheets and graphene oxide（GO）were used to reinforce carboxylated nitride rubber（XNBR）.And the effects of BNNS and BNNS/GO on the structure and properties of XNBR were investigate,respectively.Firstly,BNNS were synthesized by exfoliating hexagonal boron nitride（h-BN）with chemical exfoliation method.Then modified BNNS（PBNNS）were obtained by modifying BNNS with polyvinylpyrrolidone（PVP）.The PBNNS/XNBR vulcanizates were prepared by blending PBNNS with XNBR emulsion.And the effects of the amount of PVP on the structure and performance of the PBNNS/XNBR vulcanizates were studied.It is shown that with the increase of the amount of PVP,the mechanical properties and thermal conductivity of PBNNS/XNBR vulcanizates increase first and then decrease,while thermal stability of PBNNS/XNBR vulcanizate decrease.When the mass ratio of PVP to BNNS is 1:1,the tensile strength,tear strength,100%modulus(M₁₀₀),300%modulus(M₃₀₀)and thermal conductivity of XNBR vulcanizate are increased by 24.5%,5.5%,32.0%,33.6%and 24.7%,respectively,compared with neat XNBR.Secondly,the effects of PBNNS content on the properties of PBNNS/XNBR vulcanizates were studied.The results show that with the increase of PBNNS content,the mechanical properties of PBNNS/XNBR vulcanizates gradually increase,and the thermal conductivity of PBNNS/XNBR vulcanizates increase first and then decrease,while the thermal stability of PBNNS/XNBR vulcanizates decreases.When the amount of PBNNS is 3 phr,the tensile strength,elongation at break,M₁₀₀,M₃₀₀ and the thermal conductivity of the PBNNS/XNBR vulcanizes are increased by 52.4%,5.0%,27.43%,38.02%,and 41.9%.respectively,compared that of neat XNBR.At last,GO was synthesized by Hummers method.The effects of the ratio of GO and PBNNS on the structure on the structure and properties of PBNNS/GO/XNBR vulcanizates was invetigated.The results show that with a certain filler content（3 phr）,the mechanical properties and thermal stability of the PBNNS/GO/XNBR vulcanizate increase with the increasing of GO,while the thermal conductivity of XNBR vulcanizate decreases.When the mass ratio of PBNNS to GO is 1:1,the tensile strength,M₁₀₀,M₃₀₀,tear strength and thermal conductivity of the vulcanized rubber are increased by 118.5%,50.9%,68.9%,40.6%and14.7%,respectively,compared with the neat XNBR.