Cure mechanism and process optimization of biobased Glass/Polyfurfuryl alcohol prepreg for rapid manufacturing
Topic(s) : Manufacturing
Co-authors :
Daniel ODIYI (UNITED KINGDOM), Tahir SHARIF (UNITED KINGDOM), Rizwan CHOUDHRY (QATAR)Abstract :
Concerns over global sustainability and emissions from the production and use of fossil-based resin systems have driven research and demand for environmentally friendly, bio-based alternatives to fiber reinforced composites. One such alternative is polyfurfuryl alcohol (PFA) resin. Primarily known for its excellent flame-retardant properties, PFA resin has demonstrated impressive mechanical and thermal properties when used in fiber reinforced composites. As such, it has been touted as a good alternative to phenolic resin. However, manufacturing PFA resin and its reinforced composites can be difficult. Due to these difficulties, PFA resin and its reinforced composites are often manufactured using relatively slow curing processes like oven or autoclave curing, which can take up to several hours.[1]. This poses a major drawback potentially limiting the use of this bio-based material for high volume production where time saving, and shorter cure cycles are vital. Therefore, it is essential to optimize the processing parameters suitable for rapid manufacturing processes such as compression moulding (hot press). Recent efforts by researchers on this biobased resin system have been largely focused on better understanding of its molecular chemistry [2,3].However, to date, there is very limited literature available related to curing kinetics and mechanism on the fibre reinforced PFA prepreg which can facilitate the manufacture of good quality laminate with fast throughput rate.
In this study, we optimized the curing cycle of Glass reinforced Polyfurfuryl alcohol prepreg for rapid manufacturing. The Friedman and Ozawa-Flynn wall cure kinetic models were employed to investigate the curing kinetics of the glass/PFA prepreg system. The results elucidated the curing activation energy and the complex curing mechanism of chemical reactions leading to the formation of a thermally stable matrix. Furthermore, the excellent correlation between the Friedman model and experiments enabled the prediction of the curing time evolution under isothermal conditions leading to an optimized cure cycle of 160°C for 30 minutes from the manufacturer's recommended 130°C for a total of 113 minutes.
To verify the kinetic prediction results and substantiate kinetic model recommendations, a series of experimental studies comparing composite laminates manufactured based on the optimized cure cycle in a hot press and the prepreg manufacturer's recommended cure cycle manufactured in the oven were performed. The experimental study program included tensile, flexural, and interlaminar shear strength tests.
In this study, we optimized the curing cycle of Glass reinforced Polyfurfuryl alcohol prepreg for rapid manufacturing. The Friedman and Ozawa-Flynn wall cure kinetic models were employed to investigate the curing kinetics of the glass/PFA prepreg system. The results elucidated the curing activation energy and the complex curing mechanism of chemical reactions leading to the formation of a thermally stable matrix. Furthermore, the excellent correlation between the Friedman model and experiments enabled the prediction of the curing time evolution under isothermal conditions leading to an optimized cure cycle of 160°C for 30 minutes from the manufacturer's recommended 130°C for a total of 113 minutes.
To verify the kinetic prediction results and substantiate kinetic model recommendations, a series of experimental studies comparing composite laminates manufactured based on the optimized cure cycle in a hot press and the prepreg manufacturer's recommended cure cycle manufactured in the oven were performed. The experimental study program included tensile, flexural, and interlaminar shear strength tests.