Prepation And Performance Study Of Lignin/EPDM Composites

Lignin,a unique type of aromatic biopolymer,widely exists in the nature and has excellent antiaging and ultraviolet?UV?resistance performance.However,most of the industrial lignin is burned off,the effective utilization of resources is very low.EPDM is widely used in sealing strips and waterproof rolls,but the strength of raw rubber is very low,it must be reinforced by filler.Carbon black is commonly used to reinforce EPDM in the industrial,but the production cost of carbon black is high,and it relies heavily on petrochemical resources.If carbon black can be partially replaced by lignin to strengthen EPDM,it can not only reduce production costs,improve the anti-aging performance of EPDM,but also reduce environmental pollution,which is of great significance for the high-value utilization of industrial lignin waste.However,lignin particles are easy to aggregate in EPDM due to the strong intermolecular hydrogen bonds that derives from rich polar oxygen-containing functional groups,meanwhile,it has poor compatibility with EPDM.As a result,composites prepared by directly blend lignin with EPDM will suffer from a poor mechanical property.In order to prepare EPDM/lignin composites with good mechanical property,it must aim to inhibit aggregation of lignin and improve the compatibility between lignin and EPDM,this paper tried to build hydrogen bonds between enzymatic hydrolysis lignin?EHL?with EPDM and EPDM-MA?maleic anhydride grafted EPDM?,intensify the interaction between lignin and EPDM,EHL/EPDM composites and EHL/EPDM-MA composite with good mechanical property was prepared.On the basis,Zn²⁺coordination bond was introduced into lignin/carbon black/EPDM ternary composites,A series of lignin/carbon black/EPDM ternary composites were prepared.The effects of metal coordination bond on mechanical properties of EPDM ternary composites were systematically studied.The major findings of the present study can be summarized as follows:?1?In order to build hydrogen bond interaction between lignin and EPDM,3-amino-1,2,4-triazole?ATA?modified POE-MA was introduced to the enzymatic hydrolysis lignin/EPDM composites as a reactive compatibilizer.The hydrogen bond can promote the dispersion of lignin in EPDM and strengthen the interface interaction,finally improve the tensile strength and modulus of EPDM/lignin composites.?2?EPDM-MA?maleic anhydride grafted EPDM?was used as the elastomer matrix,then ATA react with MA group on EPDM,hydrogen bond interaction could also be established between the enzymatic lignin and EPDM matrix,which can strengthen the interface interaction between lignin and EPDM,and dramatically increase the modulus and tensile strength of the lignin/EPDM-MA composites.?3?It can further effectively improve the comprehensive mechanical properties of the composite by introducing Zn²⁺coordination bond into lignin/carbon black/EPDM ternary composite system.Compared with the ternary complex system without Zn²⁺coordination bonds,the lignin dispersion become better and the phase interface with EPDM gradually become fuzzy after the introduction of ZDMA.When the addition amounts of lignin and carbon black were 20 respectively,the tensile strength of L20C20Z12 sample with 12 pieces of zinc methacrylate?ZDMA?was up to 24.5 MPa,close to or even higher than that of pure carbon black?the tensile strength of EPDM with 40 pieces of carbon black was up to 22.8MPa?.The tensile strength and elongation at break conservation rate of EPDM composite with 40 pieces of carbon black after 72 h thermo-oxidative aging were 71.5%and 78.7%,respectively,while conservation rate of EPDM composites with 20 pieces of lignin and carbon black content were all above 90%,and the elongation at break was greater than 85%,showing significantly better thermal oxygen aging resistance.