Journal of Adhesion Science and Technology, Vol.18, No.11, 1217-1224, 2004
Adhesive properties of blends of phenol/cardanol-formaldehyde copolymer resin with polychloroprene rubber
This is a continuation of an earlier study on the adhesive properties of neoprene-phenolic resin blends. The phenolic resin used is derived from a mixture of phenol and cardanol, a renewable resource. Having established the utility of cardanol for formulating adhesives, this study investigates the effect of varying the phenol: cardanol ratio in the formulation. The effect of varying the total resin content at various phenol/cardanol ratios is also studied. It is found that a phenol/cardanol ratio of 80: 20 is optimum for shear strength of aluminum-aluminum bonds, while a 60: 40 ratio is the best for peel properties. For SBR-SBR and SBR-Al bonds, a 60:40 ratio is optimum for both peel as well as shear strength. Further, an 80 phr total resin content in the primer and a 40 phr resin content in the adhesive are found to give the best shear and peel strengths for SBR-Al bonds. The study reveals that the copolymer based on phenol, cardanol and formaldehyde is a better choice for the resin than either of the individual condensation products of phenol or cardanol with formaldehyde.