Catalytic and ortho-directing effect of Zn2+, Mg2+, Ba2+, and Ca2+ metal hydroxides on the preparation of phenolic-formaldehyde resin. Issue 24 (17th December 2018)

• Record Type: Journal Article
• Authors: Chen, Zhangmin; Cai, Hanjiang; Pan, Yanhong; Chen, Yuhe; Guo, Rencong; Li, Jingpeng; He, Sheng; Han, Jian
• Is Part Of: Journal of adhesion science and technology. Volume 32:Issue 24(2018)
• Page Start: 2647
• Page End: 2657
• Publication Date: 2018-12-17
• Subjects: phenolic resin -- divalent metal hydroxides -- polymerization rate -- ortho to para ratio; Adhesion -- Periodicals; Adhesives -- Periodicals; 668.3
• DOI: 10.1080/01694243.2018.1500158
• Languages: English
• ISSNs: 0169-4243

Abstract

Abstract: A one step method was employed to prepare PF (phenol-formaldehyde) resin adhesive from phenol and formaldehyde with Zn 2+, Mg 2+, Ba 2+, and Ca 2+ hydroxides as catalysts, and the physicochemical properties of the resulting polymeric material were analyzed. The viscosity of the liquid adhesive decreased at intermediate catalyst concentrations, while the polymerization rate decreased at the highest concentrations; no clear pattern could be observed between catalyst concentration and solid content. Differential scanning calorimetry (DSC) performed on the PF resin catalyzed by Ba 2+ showed that the polymer had a curing exothermic peak at around 110 °C, while the initial curing temperatures of PF resins were affected by the type of metal hydroxide used, and were in the order Ca 2+ < Mg 2+ <control sample. FTIR spectroscopy was used to monitor the degree of ortho / para substitution during the synthesis of PF resin with Ba 2+, Ca 2+, and Mg 2+ hydroxides. The highest ortho / para ratio was achieved with Ba 2+ at a concentration of 0.45 wt.%, which also resulted in the most significant increase in the polymerization rate for the formation of PF resin.