A study on the effect of starch–polyvinyl alcohol blends by addition of citric acid and boric acid for enhancement in performance properties of polyvinyl acetate-based wood adhesive
Wood adhesives with enhanced properties were prepared by incorporating either citric or boric acid. The citric acid and boric acid were added in the presence of water being the polymers and acids readily soluble in water. The reaction was carried out at a relatively lower temperature in order to prevent water evaporation and damage to the starch structure. Two series of adhesives were prepared with varying starch and polyvinyl acetate content. The adhesives were characterized by Fourier-transform infrared spectroscopy and dynamic mechanical analysis. The effects of citric and boric acid on performance properties like wet tack, tensile shear strength, rheology and viscosity stability were studied. The results showed that by addition of acids there is an increase in mechanical strength, viscosity and wet tack in the case of boric acid. Similarly, better viscosity stability was observed due to addition of citric acid. From the tests conducted, it can be concluded that the composition for optimum level performance and stability is at 0.3 wt% of citric acid and 0.1 wt% of boric acid of the total composition of adhesive.
KeywordsBoric acid Citric acid Wood adhesive Starch Polyvinyl alcohol Polyvinyl acetate
- Gu R, Mu B, Guo K (2013) Structural characterization of Konjak powder-chitosan-PVA blending adhesive. Nongye Gongcheng Xuebao/Trans Chin Soc Agric Eng 29:277–283. https://doi.org/10.3969/j.issn.1002-6819.2013.07.035 CrossRefGoogle Scholar
- Imam SH, Mao L, Chen L, Greene RV (1999) Wood adhesive from crosslinked poly(vinyl alcohol) and partially gelatinized starch: preparation and properties. Starch - Stärke. https://doi.org/10.1002/(sici)1521-379x(199906)51:6<225::aid-star225>3.0.co;2-fGoogle Scholar
- Kusumah SS, Umemura K, Yoshioka K, Miyafuji H, Kanayama K (2016) Utilization of sweet sorghum bagasse and citric acid for manufacturing of particleboard I: effects of pre-drying treatment and citric acid content on the board properties. Ind Crops Prod 84:34–42. https://doi.org/10.1016/j.indcrop.2016.01.042 CrossRefGoogle Scholar
- Sanjiv Kasbe P, Kumar N, Manik G (2017) A molecular simulation analysis of influence of lignosulphonate addition on properties of modified 2-ethyl hexyl acrylate/methyl methacrylate/acrylic acid based pressure sensitive adhesive. Int J Adhes Adhes 78:45–54. https://doi.org/10.1016/j.ijadhadh.2017.06.014 CrossRefGoogle Scholar