Study On Carbon Nanomaterials Filled Brominated Butyl Rubber Composites

Brominated butyl rubber?BIIR?has low permeability and high Corrosion resistance,is mainly used to make inner tubes and sealing materials.Filling graphene and carbon nanotube can improve its mechanical properties,gas barrier properties and thermal conductivity and improve its application value in the field of tire and sealing materials.A key point to prepare high performance graphene/polymer composites is the dispersion of graphene.Graphene oxide?GO?can be easily exfoliated and modified,it provides an effective way to solve the problem.In this thesis,GO was prepared by Hummers method and then modified to GO-octadecylamine?GO-ODA?and RGO-calcium fluoride?RGO-CaF₂?.The as-formed two fillers were blended with BIIR by solution mixing to prepare graphene/BIIR composites.The relationship between the structure and the properties of the graphene/BIIR composites was investigated.Boron nitride?BN?and multi-walled carbon nanotube?MWCNT?were also blended with BIIR to improve the mechanical and thermal conductivity properties of BIIR.The main work was discussed as follows:GO-ODA/BIIR composites were prepared by solution mixing method and their mechanical properties,thermal stability and gas barrier properties were investigated.The GO-ODA/BIIR composites had much better mechanical properties than that of BIIR.The stress at 300%extension of BIIR increased 230%after the addition of 10 phr GO-ODA.The improved mechanical properties benefited from the strong interaction between GO-ODA and BIIR.The thermal stability of GO-ODA/BIIR composites was improved with increasing GO-ODA loading.GO-ODA/BIIR composites had better gas barrier properties than BIIR,and the gas transmission rate of10 phr GO-ODA/BIIR composite was only 21.2%of that of BIIR.The well dispersed GO-ODA sheet in BIIR matrix formed a tortuous pathway and restricts the motion of polymer chains,thus made it difficult for gas to pass.RGO-CaF₂/BIIR composites were prepared by solution mixing method,their mechanical,dielectric and thermal conductivity properties were investigated.The CaF₂ particles efficiently prevented the stacking of the RGO sheets,thus graphene was homogeneously dispersed in the RGO-CaF₂/BIIR composite.The RGO-CaF₂/BIIR composites had much better mechanical properties than BIIR.The stress at 300%extension of BIIR increased 72%after the addition of 3 phr RGO-CaF₂.Both dielectric constant and thermal conductivity of RGO-CaF₂/BIIR composites increased with increasing RGO-CaF₂ loading.The thermal conductivity of 5 phr RGO-CaF₂/BIIR composite was 65%higher than that of BIIR.Because of the synergistic effect of RGO and CaF₂,dielectric constant and thermal conductivity of RGO-CaF₂/BIIR composites were higher than those of RGO/BIIR or CaF₂/BIIR composites.Both BN and MWCNT can improve the mechanical properties and the thermal conductivity of BIIR.The stress at 300%extension and thermal conductivity of BN/MWCNT/BIIR composite?5/60/100?was 4.9 and 3.1times of that of BIIR,respectively.According to the theoretical simulation on the mechanical properties and the thermal conductivity,the MWCNT's contribution to the improvement of the BN/MWCNT/BIIR mechanical properties was greater than that of BN,and BN played a dominant role in improving the thermal conductivity of the BN/MWCNT/BIIR composites.There was a synergistic effect between BN and MWCNT when improving the thermal conductivity of BIIR.