Spectroscopic Analysis of the Interface for Wheat Straw Specimen Glued with PMDI

Authors

  • Zhi-Ming Liu
  • Feng-Hu Wang
  • Xiang-Ming Wang

Keywords:

CP/MAS C-13 NMR, ESCA (XPS), functional group, interface, micro-FTIR, PMDI resin, wheat straw

Abstract

In order to obtain information about chemical characteristics on the interaction between wheat straw and PMDI, the exterior and interior surfaces of wheat straw, and the interface of wheat straw specimen glued by polymeric diphenylmethane diisocyanate (PMDI) resin were scanned by micro-Fourier Transform Infrared Spectroscopy (micro-FTIR) and Electron Spectroscopy for Chemical Analysis (ESCA), respectively. The specimens of pure cellulose and the reacted mixture of cellulose with PMDI resin were analyzed by FTIR and cross polarization/magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS C-13 NMR). Scanning by micro-FTIR showed that the major differences in functional groups between exterior and interior surfaces for the same section of wheat straw appeared in the fingerprint region (400 cm-1 to 1500 cm-1). There were a few differentiated peaks in the region of 1174~1000 cm-1 for the interior surface, whereas there was greater absorption in the exterior surface than in the interior surface, especially at 987 cm-1. Generally, there were reaction functional groups (-OH) on exterior and interior surfaces for wheat straw. ESCA scanning and curve-fitting of the C1S peaks showed that the relative content of the functional group on the exterior surface differed from that of the interior surface. Results of ESCA scanning of the interface for wheat straw specimen glued with PMDI indicated that the glued interface chemically adsorbed PMDI resin. Furthermore, the contents of functional groups of the interface specimen glued with PMDI differed from those of the specimen without PMDI. Using FTIR and CP/MAS C-13 NMR, the results imply that N=C=O functional group for PMDI could react with cellulose.

References

Andrade, J. D. 1985. X-ray photoelectron spectroscopy. Pages 105-163 in J. D. Andrade, ed. Surface and interfacial aspects of biomedical polymers. Plenum Press, New York, NY. Vol. I.nBriggs, D., and M. P. Seah. 1985. Practical surface analysis. 2nd ed. John Wiley and Sons. Chichester, NY. Vol. 1. Pp. 1-17.nBrowning, B. L. 1963. The chemistry of wood. Interscience Publishers, New York, NY. Pp. 129-131.nChelak, W., and W. H. Newman. 1991. MDI high moisture content bonding mechanism, parameters, and benefits using MDI in composite wood products. Pages 205-229 in Proc. 25th International Particleboard/Composite Materials Symposium. Apr. 9-11, 1991, Washington State University, Pullman, WA.nDe Bruyne, N. A. 1965. Adhesion and adhesives. Edited by R. Houwink and G. Salomon. Elsevier Publishing Company, New York, NY. Vol. 1. Pp. 281-283.nGaboriaud, F., and J. P. Vantelon. 1982. Mechanism of thermal degradation of polyurethane based on MDI and propoxylated trimethylol propane. J. Polym. Sci. Part A, Polym. Chem.8:2063-2071.nGurke, T. 2002. Further developments in the area of polymeric MDI. Rubber and Plastics Research Abstracts. 03-06 878609 NDN-131-0140-6532-0.nHarper, D. P., M. P. Wolcott, and T. G. Rials. 2001. Evaluation of the cure kinetics of the wood/pMDI bondline. Int. J. Adhesion Adhesives2:137-144.nHirai, A., F. Horii, and R. Kitamaru. 1985. CP/MAS Carbon-13 NMR study of native (cotton, ramie, valonia and bacterial) and regenerated cellulose with different water contents. Pages 277 in Proc. International Symposium on Fiber Science and Technology. Aug. 20-24, 1985, Hakone, Japan.nHorii, F., A. Hirai, and R. Kitamaru. 1984. Crosspolarization/magic-angle-spinning Carbon-13 NMR study. Pages 27-42 in J. C. Arthur, ed. Molecular Chain Confirmations of Native and Regenerated Cellulose. Polymers for Fibers and Elastomers.nJung, H. C., S. J. Kang, S.-B. Kim, W. N. Kim, Y.-B. Lee, K. H. Choe, and S.-H. Hong. 2000. Properties of crosslinked polyurethanes synthesized from 4,4 primediphenylmethane diisocyanate and polyester polyol. J. Appl. Polym. Sci.78(3):624-630.nKazayawoko, M., J. J. Balatinecz, and R. N. S. Sodhi. 1999. X-ray photoelectron spectroscopy of maleated polypropylene treated wood fibers in a high-intensity thermokinetic mixer. Wood Sci. Technol.33(5):358-372.nLiu, Z. M., F. H. Wang, and R. Z. Su. 2002. Analysis on structural features and surface elements of wheat straw. J. Northeast Forestry Univ.30(2):62-65.nLiu, Z. M., F. H. Wang, and X. M. Wang. 2004. Surface structure and dynamic adhesive wettability of wheat straw. Wood Fiber Sci.36(2):239-249.nMatuana, L. M., J. J. Balatinecz, R. N. S. Sodhi, and C. B. Park. 2001. Surface characterization of esterified cellulosic fibers by XPS and FTIR Spectroscopy. Wood Sci. Technol.35(3):191-201.nMoriaty, C. 1999. Recent improvements in emulsifiable pMDI for the MDF industry. Pages 159-164 in Proc. 33rd International Particleboard/Composite Materials Symposium. Apr. 13-15, 1999, Pullman, WA. Washington State University.nNikitin, N. I. 1966. The Chemistry of Cellulose and Wood. Translated from Russian by J. Schmorak. Jerusalem, Israel Program for Scientific Translations. Pp. 58-59.nPaper and Pulp Manual (Part one). 1987. Cellulose Materials and Chemical Industry Materials. Light Industry Publication, Beijing.4:74-116; 130-176.nSu, R. Z., Z. M. Liu, J. Li, and J. Ai. 2002. Study on silica distribution of wheat straw surface. Scientia Silvae Sinicae38(6):99-102.nTakahashi, M., and M. Ookubo. 1994. Cross Polarization/Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS C-13 NMR) and Wide Angle X-ray Spectroscopic (WAXS) Assessments of the Effects of Starting Cellulose Materials on the Transition between Cellulose Polymorphs. Kobunshi Ronbunshu51(2):107-113.nWang, J. Q., W. H. Wu, and D. M. Feng. 1992. The Introduction of Electron Spectrum (XPS/XAES/UPS). Defense Industry Publication, Beijing, China. Pp. 21-168.n

Downloads

Published

2007-06-05

Issue

Section

Research Contributions