Study On The Effect Of Long-chain Alkyl Phenol On The Properties Of Phenolic Resin And Its Foaming Materials

Looking around our modern world,we will encounter all kinds of polymeric materials,because they are used in a variety of applications,and phenolic foam plastics have excellent properties,such as significant heat resistance and excellent flame retardancy.In addition,phenolic foam is one of the cheapest polymers that can be purchased,and is widely used in aerospace,flowers,noise insulation,transportation,etc.However,phenolic foam is easy to embrittlement and easy to produce slag,which will affect its further application and development.Therefore,the researchers modified the phenolic resin molecular structure to improve the toughness,heat resistance,aging resistance and wear resistance of phenolic foam,thereby expanding the application area of phenolic foam and meeting the needs of different industries.The purpose of this paper is to modify phenolic resin and improve the toughness of phenolic foam.In order to improve the toughness of phenolic foam,chemical modification of phenolic resin was carried out.In this paper,three kinds of alkylphenols with different length of carbon long chain on the para position were selected as modifier.The alkylphenols were 4-pentylphenol with five carbon long chain,4-nonylphenol with nine carbon long chain and4-dodecylphenol with twelve carbon long chain.Surfactants were added to the modified phenolic resin to reduce the surface tension.Foaming agent vaporizes in resin to form cell structure.Finally,the phenolic foam is solidified under the action of the curing agent.The molecular structure of the modified phenolic resin is analyzed,and the solid content,free formaldehyde and gel time are tested.The flexural displacement,compressive strength and bending strength of the phenolic foam are tested,and the apparent density and water absorption rate of the foam are tested.The experimental results show that the mechanical properties of the modified phenolic foam are improved.When the amount of 4-amyl phenol added to five carbon long chain was 6%,the toughness of phenolic foam reached the best,the bending displacement increased by 213% compared with the common phenolic foam,and the compressive strength and bending strength increased by 135% and 50% respectively than those of ordinary phenolic foam.When the content of 4-nonylphenol in nine carbon long chain was 2%,the toughness of phenolic foam reached the best,the bending displacement increased by 176% compared with the common phenolic foam,and the compressive strength and bending strength increased by 129% and 35%respectively than that of ordinary phenolic foam.When the content of 4-twelve alkyl phenol in the twelve carbon long chain was 0.4%,the toughness of phenolic foam reached the best,the bending displacement increased by 54%compared with the common phenolic foam,and the compressive strength and bending strength increased 117% and 30% respectively than that of ordinary phenolic foam.Since alkyl phenol is substituted by substituted phenols,it occupies an active site,and the carbon long chain will produce steric hindrance.As a result,the twelve alkylphenols have the worst performance and the greatest influence on the foam properties.The addition of 4-nonylphenol is less than 4-amyl phenol,which reduces the hindrance caused by steric hindrance,and makes the performance of the 4-alkyl phenol modified phenolic foam almost the same.