Development of cardanol‐bonded cellulose thermoplastics: High productivity achieved by using isocyanate‐modified cardanol

Abstract

A highly efficient process of synthesizing a cardanol‐bonded cellulose thermoplastic has been developed by using isocyanate‐modified cardanol. As recently shown by us, the thermoplastic consisting of cellulose diacetate (CDA) and cardanol extracted from cashew nutshells performed high practical properties such as bending strength, heat resistance and water resistance. However, its synthesis process by esterification using acid chlorides of cardanol in a solvent as a common procedure, required high energy consumption by using a large amount of poor solvent to isolate the resulting product from the solvent. Using an isocyanate‐modified cardanol, 3‐pentadecylcyclohexyl (6‐isocyanatohexyl) carbamate (PICC) greatly improved the productivity of the modified cardanol‐bonded CDA (PICC‐bonded CDA). After bonding PICC to CDA in a solvent, the remaining PICC coagulated and was easily removed by filtration, which resulted in remarkably simplifying the separation process of the product. The resulting PICC‐bonded CDA showed insufficient thermoplasticity due to its high interaction between PICC parts. Additional bonding propionyl group improved the thermoplasticity while maintaining good thermal and mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1578–1587, 2013

Development of Cardanol-Bonded Cellulose Resin with Nonfood Plant Resources: Low Energy Heterogeneous Synthesis Process

“…While thermoplasticity of the intermediate product was low, it was improved by over 10 times, as measured by melt flow rate, after the second step, reaching sufficient level for injection molding. The solvent usage of the two-step heterogeneous process was compared with that of a homogeneous process (12,13) (Figure 4). Solvent usage could be reduced by about 90% mainly because of the elimination of poor solvent.…”

“…The remaining reactant of PAA needed to be separated from the resin by precipitation with a poor solvent because it cannot be separated by distillation with low energy use due to its high boiling point. To cut back on poor solvents, which require large amounts of energy for distillation, another process to utilize isocyanate-modified cardanol was studied (12). Although products could be isolated readily only by evaporating a reaction solvent, the starting material was also CDA, which had been produced by a conventional homogeneous process.…”

Development of cardanol-bonded cellulose thermoplastics: high productivity achieved in two-step heterogeneous process

“…Homogeneous process using CDA as starting material Using CDA as a starting material and dissolving it in 1,4-dioxane, cardanol-bonded cellulose resin (PAAbonded CDA) was synthesized, as reported previously (Tanaka et al 2013). PAA chloride was used as a PAA reactant and methanol was used as poor and washing solvents.…”

“…The poor solvent is also needed to remove the remaining reactant of PAA from the product by precipitation because the reactant cannot be separated by distillation with low energy use due to its high boiling point. To cut back on poor solvents, another process using isocyanate-modified cardanol was studied (Tanaka et al 2013). In this process, isocyanatemodified cardanol is bonded to CDA dissolved in a solvent.…”

Improvement in impact strength of modified cardanol‐bonded cellulose thermoplastic resin by using olefin resins

“…[7][8][9] As shown in Figure 1, bonding a modifiedcardanol derivative (PAA) with cellulose diacetate (CDA) resulted in a bioplastic (PAA-bonded CDA) having good thermoplasticity, high strength, and high heat and water resistance, which were superior to those of conventional cellulose resins such as CDA with plasticizers including triethyl citrate (TEC). However, the impact strength of PAA-bonded CDA was insufficient for use in durable products.…”