Fortified mangrove tannin-based plywood adhesive

✍ Scribed by S. Sowunmi; R. O. Ebewele; A. H. Conner; B. H. River

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 454 KB
• Volume: 62
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19961017)62:3<577::aid-app15>3.0.co;2-w

✦ Synopsis

Mangrove bark tannin adhesives are based on a renewable resource. They are potential substitutes or supplements for phenol-formaldehyde (PF) wood-bonding adhesives which are derived from petroleum, a finite natural resource. However, mangrove tannin adhesives exhibit poor adhesive properties including poor wet strength, brittleness, and poor wood penetration. These problems were addressed by treating tannin extract with acetic anhydride and then sodium hydroxide followed by modification with 20% resole-type P F resin. Significant structural changes occurred after the chemical treatment. Heat of reaction of tannin with formaldehyde was increased while the activation energy was drastically reduced. Premature cure was also reduced. The fortified formulations had good plywood adhesive properties.