A study on the kinetics of condensation reaction of cardanol and formaldehyde, part I

Abstract

Novolac resins having cardanol-to-formaldehyde mole ratios of 1:0.4, 1:0.5, and 1:0.6 were prepared by using aromatic sulphonic acid as the catalyst at four different temperatures ranging between 90 • C and 120 • C, with an interval of 10 • C. Free formaldehyde and free phenol contents were determined at regular time intervals to check the completion of the reaction. The synthesized novolacs were characterized by Fourier-transform infrared spectroscopic analysis, nuclear magnetic resonance, and gel permeation chromatography. The reaction between cardanol and formaldehyde was found to follow second-order kinetics. The overall rate constant (k) increased with the increase of temperature. On the basis of the value of k, various other activation parameters such as activation energy (E a ), change in enthalpy ( H ), entropy ( S), and free energy ( G ) of the reaction were also evaluated. It was found that the condensation reaction of cardanol and formaldehyde with aromatic sulphonic acid was nonspontaneous and irreversible.

Process modeling, optimization and analysis of esterification reaction of cashew nut shell liquid (CNSL)-derived epoxy resin using response surface methodology

“…Resins derived from CNSL/cardanol are widely employed in the field of surface coatings, adhesives, laminates, rubber compounding and have several miscellaneous applications. Cardanol, like phenol, can be condensed with active hydrogen containing compounds such as formaldehyde to yield a series of phenolic resins, for instance, base-catalyzed resoles and acid-catalyzed novolacs [1][2][3][4][5][6][7][8][9]. The cardanol-based novolac-type phenolic resins may be modified to develop epoxy resins with epichlorohydrin to enhance the performance of such resins in various fields [10][11][12][13].…”

Synthesis and characterization of novel vinylester prepolymers from cardanol

“…Several publications from Sultania et al are related to the synthesis of VE resins from cardanol . First, a cardanol‐based novolac precursor was synthesized from cardanol and formaldehyde . Then, the epoxidation of the cardanol‐based novolac precursor is conducted with epichlorhydrin .…”

Recent Development of Cardanol Based Polymer Materials-A Review

“…An irreversible non-spontaneous second-order reaction using cardanol with formaldehyde in the presence of organic weak acids such as p-toluenesulfonic acid, ethanedioic acid, amber acid and citiricacid acid as the catalyst was carried out [59][60][61]. In all the systems, the value of step rate constant k1 were found to be lower than k2, thus the condensation reaction may be considered as the rate-determining stage of the whole reaction.…”