The Research On Phenolic Resin Modified By Organic And Inorganic Nanoparticles

Phenolic resins have been widely used in many fields due to their excellent flame resistance, insulativity, adhesivity and chemical resistance.But the inherent brittleness and the lack of heat resistance hindered their widespread applications. In order to improve the performance of phenolic resins, and further expand their scope of application, they should be modified to improve toughness and heat resistance. This paper studied phenolic resins separately modified by nano carboxylic acrylonitrile butadiene rubber latex (XNBRL) and carbon black, the former is mainly to improve the toughness and to be used as adhesive for friction materials; the later is mainly to improve the heat resistance and to be used as binding for refractory brick.In this paper, we prepared and characterized nano carboxylic acrylonitrile butadiene rubber latex-toughened-phenolic resins (XNBRL-PF). The results showed that the impact strength, viscosity and free phenol content of XNBRL were remarkably improved with the increasing of latex content. Scanning electron microscope (SEM) analysis of the fracture surface of the XNBRL-PF indicated that the XNBRL were uniformly dispersed in the PF matrix, with diameters ranging from 200-400nm. The results of Fourier transform infrared spectroscopy (FT-IR) proved that chemical reaction occurred between XNBRL and PF matrix, which can greatly improve the interface interaction between rubber particles and PF matrix. Thermo gravimetric analysis (TGA) test showed that the incorporation of XNBRL can improve the thermo stability of PF at low temperatures(≤400℃), especially elevated the initial decomposition temperature. Finally, XNBRL-PF meets the demands of an adhesive of friction materials.We also prepared and characterized nano carbon black modified phenolic resin in this paper. Ultrasound was used to improve the dispersion of carbon black in the phenolic resin matrix. The surface of carbon black was treated by coupling agent KH-550, which can improve the interface compatibility between black carbon particles and phenolic resin matrix. The results of FT-IR proved that the synthesized phenolic resin was high-ortho phenolic resin, and the ortho ratio was 3.5. SEM analysis of the fracture surface of the carbon black modified phenolic resin indicated that the carbon black were uniformly dispersed in the PF matrix, with diameters ranging from 100-200nm. Thermal performance analysis showed that the solid content and residual carbon content of the carbon black modified phenolic resin were significantly increased. The performance indicators of the carbon black modified phenolic resin completely meet the requirements as a magnesite-carbon brick binder. The analyses of physical properties showed that the magnesite-carbon brick using carbon black modified phenolic resin as the binder possessed low porosity, high bulk density, high temperature hot flexural strength and high oxidation resistance. As a result, the comprehensive performance of magnesite-carbon brick was greatly improved.