Study On Modification Of Cardanol Bio-based Epoxy Resin And Properties Of Its Composites

As a high-performance thermosetting material,epoxy resins have been widely used in many fields,such as electronics,medical treatment,construction,automobile,aerospace,etc.However,most of the epoxy resins currently used are non-renewable oil resources,which will cause waste of resources and environmental pollution.Hence,considerable attention has been devoted to study bio-based epoxy resins with different synthetic methods.In this study,a series of cardanol derivative elastic thermosetting epoxy resin（NC-514s）/nanocomposites were successfully fabricated,focusing on the effects of different nanocomposites on mechanical and thermal properties of NC-514s.The main conclusions are as follows:（1）A series of Propyl-polysilsesquioxane（POSS）/NC-514s nanocomposites were prepared,using POSS as modifiers.The results showed that compared with the neat epoxy resin,the glass transition temperature（T_g）of POSS/NC-514s nanocomposites gradually increased with the increasing POSS content.For POSS/NC-514s nanocomposites with 10 wt.%POSS,the tensile strength of the sample increased by 213.4%,Young’s modulus increased by 151.3%,the elongation at break increased from 100.85%to 122.61%.This shows that when POSS was added to the epoxy matrix,the crosslinking network structure could be formed through the polycondensation reaction,thus greatly improving the tensile strength of epoxy resin.（2）A series of octaphenylaminopropyl cage polysilsesquioxane（Ph-POSS）/NC-514s nanocomposites were prepared,using Ph-POSS as modifiers and tetrahydrofuran as solvent.The results showed that compared with the neat epoxy resin,the T_g of Ph-POSS/NC-514s nanocomposites increased with increasing the Ph-POSS content.For Ph-POSS/NC-514s nanocomposites with 2.0 wt.%POSS,the thermal decomposition temperature T5%of the sample increased by 17°C,the tensile strength increased by 293.44%,and the elongation at break increased by about 175%.This indicates that the strong rigidity of aromatic hydrocarbon structure in Ph-POSS improves the thermal stability,tensile strength and toughness of epoxy resin.（3）A series of octadecylamine modified boron nitride（ODA/BN）/NC-514s nanocomposites were prepared,using ODA/BN as modifiers.The results showed that compared with the neat epoxy resin,the T_g of the sample increased gradually with increasing the ODA/BN content.For ODA/BN/NC-514s nanocomposites with 0.4 wt.%ODA/BN,the thermal decomposition temperature T_5%of the sample increased by 30°C,the tensile strength increased by about 217%,and the elongation at break increased by about 116%.It indicates that ODA/BN could provide strong interfacial bonding force after adding to the epoxy resin matrix,which makes the modified composite have higher strength,toughness and heat resistance than the neat NC-514s.