Enhancing the performance of natural rubber latex with polymeric isocyanate as cold-pressing and formaldehyde free adhesive for plywood. Issue 1 (2nd January 2023)

• Record Type: Journal Article
• Authors: Lubis, Muhammad Adly Rahandi; Falah, Faizatul; Harini, Dian; Sudarmanto, ; Kharisma, Anggi; Tjahyono, Budi; Fatriasari, Widya; Subiyanto, Bambang; Suryanegara, Lisman; Iswanto, Apri Heri
• Is Part Of: Journal of adhesion. Volume 99:Issue 1(2023)
• Page Start: 58
• Page End: 73
• Publication Date: 2023-01-02
• Subjects: Adhesion -- cold-pressing adhesive -- natural rubber latex -- plywood -- pMDI; Adhesion -- Periodicals; 541.33
• DOI: 10.1080/00218464.2021.1999233
• Languages: English
• ISSNs: 0021-8464

Abstract

ABSTRACT: A cold-pressing and formaldehyde free adhesive for plywood has been prepared by incorporating natural rubber latex (NRL) and poly(vinyl alcohol) (PVA) at a ratio of 1:1 (w/w) with different contents of polymeric 4, 4-diphenyl methane diisocyanate (pMDI) (i.e., 0, 1, 3, and 5% based on NRL-PVA solids content). Plywood panel has been manufactured with a glue spread of 200 g/cm 2 under a cold-pressing of 5.0 MPa at temperature of 27 ± 2°C for 24 hr. The optimum level of pMDI in NRL-based adhesive is then used to prepare plywood for different pressing times (2, 6, and 12 hr). The result shows that addition of pMDI-created urethane linkages from the reaction between pMDI and NRL-PVA. Increasing pMDI content shortens the gel time of NRL-based adhesive, lowers its curing temperature and activation energy, and increased the solids content and viscosity. Adhesion performance of plywood bonded with NRL-PVA/pMDI adhesive was enhanced and formaldehyde emission was reduced with increasing in pMDI content. Statistical analysis suggested that NRL-PVA/3%pMDI adhesive can be used to manufacture plywood under cold-pressing of 5.0 MPa at temperature of 27 ± 2°C for 12 hr with a dry tensile shear strength of .87 MPa and .09 mg/L of formaldehyde emission.