Impact of Curing Condition on pH and Alkalinity/ Acidity of Structural Wood Adhesives
2010 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 117, no 5, 2888-2898 p.Article in journal (Refereed) Published
Nine formulations were selected for evalu- ating the effect of different curing methods on pH and alkalinity or acidity of various structural wood adhesives. These included four phenol–formaldehyde (PF) resins with high pH, one phenol–resorcinol–formaldehyde (PRF) resin with intermediate pH, two melamine–urea–formalde- hyde (MUF) resins, and two melamine–formaldehyde (MF) resins with low pH. The four curing methods used in the study were: (1) curing at 102–105C for 1 h (based on CSA O112.6-1977), (2) four-hour curing at 66C fol- lowed by 1-hour curing at 150C (based on ASTM D1583- 01), (3) curing at room temperature overnight (based on ASTM D 1583-01), and (4) cured adhesive squeezed out from glue lines of bonded shear block samples. The effect of the different methods on pH and alkalinity/acidity of the cured adhesive depended strongly on the individual adhesives. For the PF, the alkalinity was different for the different formulations in the liquid form, while in the cured form, the difference in the alkalinity depended on the curing method used. The MF and the MUF were the adhesives most affected by the method used. In particular, the MUF showed much higher cured film pH values when cured by method 2 compared to the other three methods, while both the cured MF and MUF exhibited quite variable acidity values when cured with the different methods. The PRF showed reasonably uniform cured film pH but varying acidity values when cured with the different methods.
Place, publisher, year, edition, pages
2010. Vol. 117, no 5, 2888-2898 p.
Research subject Wood Products Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-3496DOI: 10.1002/app.32201Local ID: 15423359-a208-4eea-b349-d4d6c7570596OAI: oai:DiVA.org:ltu-3496DiVA: diva2:976354
Upprättat; 2010; 20141113 (aliwan)2016-09-292016-09-29