Preparation And Properties Of Modified Phenolic Resin Reinforced Carbon Fiber Composite Materials

Phenolic resin is an important engineering plastic,but the phenolic resin characteristics of brittle fracture.In some extent,it was limited in the insulation materials and friction areas of the use of the field.In order to solve these problems,the modification of phenolic resin from physical modification and chemical modification was studied in detail.The effects on the preparation and frictional wear properties of phenolic resin/carbon fiber reinforced phenolic resin composites were studied.The main contents and conclusions are as follows:The graphene-ferric oxide nanoparticles was prepared by one-step hydrothermal synthesis.The friction and wear characteristics of the modified phenolic resin/carbon fiber composites filled with graphene-ferric oxide nanoparticles were studied.Graphene-ferric oxide nanoparticles as filler can reduce the friction coefficient and specific wear rate.The results show that the content of graphene-ferric oxide nanoparticles is 2.0 wt%.Carbon fiber powder was used to enhance the modified phenolic resin.The thermogravimetric analysis showed that the carbon fiber powder could obviously enhance the thermal stability of the composites.The thermal decomposition temperature of the composites added with carbon fiber powder was 12% higher than that of the carbon fiber powder.And in-plane and out-of-plane conductivity of the composite material with 2.0 wt% carbon fiber powder relative to the pure composite material increased by 80% and 300%,respectively.At the same time,the influence of different load and speed on the friction and wear of the composites and the modification mechanism and mechanism of the carbon fiber powder on the composites were also discussed.The effect of different melamine addition on the friction and wear properties and thermal stability of modified phenolic resin/carbon fiber composites was investigated by using melamine modified phenolic resin from matrix structure modified phenolic resin.The thermal stability of modified phenolic resin/carbon fiber composites was improved by thermogravimetric analysis.The thermal decomposition temperature of melamine composites was about 10% higher than that of non-added composites.At the same time,the friction coefficient of the melamine modified phenolic resin/carbon fiber composite material is reduced and the wear rate is obviously reduced.Scanning electron microscopy was used to study the friction and wear mechanism of modified phenolic resin/carbon fiber composites by different modification methods.The results showed that when the particles are added,the friction and wear mechanism is mainly abrasive wear.And with the increase of stress,the force acting on the particle,the stress change occurs,and the stress concentration occurs on the surface.For matrix modification,it was found that there was little void,rake and resin breakage on the surface of the composite after dry friction.This shows that the brittleness of the resin has been improved;the matrix of the composite material has not been deformed.The friction and wear of the composites after modification is mainly based on adhesive wear and abrasive wear.The above results reveal the friction and wear mechanism of modified phenolic resin/carbon fiber composites from different aspects,and the relationship between thermal conductivity and friction and wear is obtained.The friction and wear characteristics of the modified phenolic resin/carbon fiber composites can be controlled by different modification methods,which make theoretical guidance for engineering preparation and application development.