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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #300775

Title: Comparison of adhesive properties of water- and phosphate-buffer-washed cottonseed meals with cottonseed protein isolate on maple and poplar veneers

Author
item He, Zhongqi
item Chapital, Dorselyn
item Cheng, Huai
item Dowd, Michael

Submitted to: International Journal of Adhesion and Adhesives
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2014
Publication Date: 2/3/2014
Citation: He, Z., Chapital, D.C., Cheng, H.N., Dowd, M.K. 2014. Comparison of adhesive properties of water- and phosphate-buffer-washed cottonseed meals with cottonseed protein isolate on maple and poplar veneers. International Journal of Adhesion and Adhesives. 50:102-106.

Interpretive Summary: Compared with protein isolation that uses corrosive reagents, water or buffer washing could be a low-cost and environmentally friendly method for preparation of cottonseed meal (CM)-based adhesives. This current work is a continuation of our effort to increase the knowledge on the adhesive properties of water-washed cottonseed meal (WCM), phosphate buffer (35 mM Na2HPO4/NaH2PO4, pH 7.5)-washed cottonseed meal (BCM), and cottonseed protein isolate (CSPI) by testing their adhesive properties on maple and poplar wood veneers with a wider range of press temperatures. Fourier transform-infrared spectroscopy (FT-IR) was used for comparison of the adhesive-related protein and carbohydrate components of WCM, BCM, and CSPI. Our data demonstrated that raising the press temperature improved the water resistance properties of WCM and BCM more than that of CSPI, even though WCM and BCM exhibited poor water resistance with the press temperature of 80 oC. At a press temperature of 110 oC, both the adhesive strength and water resistance properties of WCM were comparable to those of CSPI. Thus, the low-cost preparation of WCM is more suitable than CSPI as a candidate for substituting synthetic wood adhesives.

Technical Abstract: Water- and phosphate buffer (35 mM Na2HPO4/NaH2PO4, pH 7.5)-washed cottonseed meals (abbreviated as WCM and BCM, respectively) could be low-cost and environmentally friendly protein-based adhesives as their preparation does not involve corrosive alkali and acid solutions that are needed for cottonseed protein isolate (CSPI). In this work, we comparatively tested the adhesive shear strength and water resistance properties of WCM, BCM and CSPI on two hard wood veneers, maple and poplar, at press temperatures at of 80, 100, 110 and 130 oC and a press pressure of 2.8 MPa. The adhesive behaviors of the three adhesives on maple and poplar veneers were similar, although not always identical. Both the adhesive shear strength and water resistance properties of the three adhesives improved with the increase of press temperature from 80 oC to over 100oC. However, raising the press temperature improved the water resistance properties of WCM and BCM more than that of CSPI. With a press temperature of 110 oC, the adhesive shear strength and water resistance properties of WCM on both maple and poplar veneers were comparable to those of CSPI. Thus, the low-cost preparation of WCM, in comparison to the CSPI preparation, is a strong candidate for substituting synthetic wood adhesives. FT-IR spectra showed higher contents of carbohydrate in WCM and BCM than in CSPI. Cross-linking reactions between carbohydrate and protein at higher press temperatures (= 100 oC) may have contributed to the improvement of the water resistance properties of WCM and BCM.