Abstract
Preliminary studies have been carried out to cure vinylester particle reinforced resins in microwaves to reduce shrinkage of the composites. The results were encouraging. With an exposure time of 35 to 40 s and a power level of 180 W, the shrinkage of 50- and 200-ml composite samples, flyash particulate–reinforced vinylester resin, approached 0%. Despite the success, there are risks in the process of curing the vinylester resins by microwave irradiation. The styrene vapor emitted from the resins is harmful to humans and becomes an inhalation hazard. In addition, the styrene vapor in the cavity of the microwave oven may be heated by the high-voltage transformer around the oven. This may result in flashing. Even if this does not happen, the high concentration of the styrene vapor in the oven cavity may lead to an explosion. Another risk is posed by the hardening agent, methyl ethyl ketone peroxide (MEKP). When interacted with microwaves, with the resulting exothermic reaction, the MEKP could spontaneously ignite. When the usual rate of 1% to 2% of it is used in hardening the resin, however, most of its dangerous properties disappear (John R. Sweet Co. http://www.johnsweet.com undated). MEKP itself is poisonous and must be handled with care.
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REFERENCES
B. T. Astrom, Manufacturing of Polymer Composites, Chapman and Hall, London, 74–83; 432-434 (1997).
G. Pritchard (Ed.), Reinforced Plastics Durability, Woodhead Publishing, London, 282–293 (1999).
H. S. Ku, G. Van Erp, J. A. R. Ball, and S. Ayers, Shrinkage Reduction of Thermoset Fibre Composites during Hardening Using Microwaves Irradiation for Curing, Proceedings of the Second World Engineering Congress, Kuching, Malaysia, 22-25 July, 2002, 177–182 (2002).
National Research Council (NRC), Microwave Processing of Materials, National Materials Advisory Board, Commission on Engineering and Technical Systems, National Academy Press, 1–7; 11-12; 100; 105 (1994).
J. Thuery, Microwaves: Industrial, Scientific and Medical Applications, Artech House, Paris, 159–380 (1992).
A. C. Metaxas, and R. J. Meredith, Industrial Microwave Heating, Institution of Electrical Engineers, Peter Peregrinus, London, 5–6; 28-31; 43; 211; 217; 278; 284-285 (1983).
SIRC (Styrene Research and Information Centre), Information on the Regulatory Treatment of Styrene, 1988, www.styrene.org/sircreg2. html
Fibre Glast Development Corporation, MSDS Promoted vinylester resin, undated, www.fibreglast.com/msds/01110.html
John R. Sweet, Co., MSDS for MEKP, undated, www.johnrsweet. com/mekp/html
H. S. Ku, E. Siores, J. A. R. Ball, and B. Horsfiled, Permittivity measurement of the thermoplastic composites at elevated temperature, J. Microwave Power Electromagn. Energy, 36,2, 101–111 (2001).
S. T. Peters, Handbook of Composites, Chapman & Hall, Melbourne, 1998.
H. S. Ku, G. Van Erp, J. A. R. Ball, and S. Ayers, Shrinkage Reduction of Thermoset Matrix Particle Reinforced Composites During Hardening Using Microwave Irradiation, Transactions, Institution of Engineers, Australia, (2002), submitted for publication.
S. Kalpakjian, Manufacturing Processes for Engineering Materials, 2nd Ed., Addison-Wesley, Reading, MA, 704 (1991).
H. S. Ku, G. Van Erp, J. A. R. Ball, and S. Ayers, Shrinkage Reduction of Vinylester Composites During Hardening using Microwaves, The Second International Conference on Advanced Materials Processing, Singapore, December 2-4, 2002, submitted for publication.
C. Y. Tong, New Syllabus Certificate Chemistry: Comprehensive Notes, Greenwood Press, Hong Kong, 116 (1998).
R. J. Meredith, Engineers' Handbook of Industrial Microwave Heating, Short Run Press, London, 151–155 1998.
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Ku, H. Risks Involved in Curing Vinylester Resins Using Microwave Irradiation. Journal of Materials Synthesis and Processing 10, 97–106 (2002). https://doi.org/10.1023/A:1021235628004
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DOI: https://doi.org/10.1023/A:1021235628004