Preparation Of High Performance Aging Resistant Rubber With Halloysite-Loaded Antioxidant 4010NA

The output and usage of rubber products are very huge.However,in the process of processing,storage and use,the physical and chemical properties and mechanical properties of elastomeric materials decrease gradually due to aging caused by combined effects of internal and external factors,and finally lose their use value.In industry,antioxidants are mainly used to delay the aging process of rubber.However,antioxidants with small molecules tend to migrate to the surface of elastomeric products between elastomeric macromolecule crosslinking networks,resulting in "blooming" phenomenon,reducing the protective effect of antioxidants on products,causing surface defects of products,polluting the use environment and affecting the adhesion of products.Therefore,it is urgent to find a new method to prolong the action time of antioxidant without causing blooming to improve the aging resistance of elastomeric composites.In this project,halloysite nanotubes with hollow tube cavity structure,which are used to load antioxidants.The release process of antioxidant 4010NA in rubber matrix was studied.The details are as follows:(1)The influence of halloysite before and after purification on the loading rate of antioxidant was compared.The results showed that the loading rate of unpurified halloysite fluctuated greatly when the concentration of antioxidant solution was 100 g/L.After purification,the loading rate remained stable at about 14%.Comparing the application effect of loaded antioxidant halloysite in NBR,BR,NR and mixed rubber,the vulcanization time of rubber composites with loading antioxidant halloysite is shortened,and the elongation at break remains higher after aging for 7 days,which has slight influence on wear resistance and tear strength.However,in natural rubber,the loading rate of halloysite on antioxidant should not be too high,and about 7%is more appropriate.(2)Halloysite has reinforcing effect.It can play a dual role after loading antioxidant.We use it to replace part of carbon black in the original formula.Tensile property test shows that 10 phr halloysite replace 7 phr carbon black is more suitable.SEM and XPS tests prove that halloysite has a slow release effect on antioxidant.After 7 days of aging,the amount of antioxidant ejected decreases and prolonged the aging resistance of rubber.At the same time the filler dispersion is more uniform,wear resistance and tear strength slightly decreased.(3)In order to extend the use time of antioxidant,Polyphenols and Polyamines was used to modify the halloysite loaded with antioxidant.The treatment time was determined by SEM,water contact angle and slow-release method,it shows 6 hours is enough.It greatly slowed down the release time of antioxidant,and the elongation at break remained about 62%after aging for 7 days.The combination effect of halloysite modified by Polyphenols and Polyamines with rubber matrix is better,the tensile strength and wear resistance of rubber are improved,the tear strength and the dispersion uniformity of filler are slightly reduced.