THE RELATIONSHIP OF THE DEGREE OF CURE TO THE PERFORMANCE OF VINYL ESTER GLASS FIBER REINFORCED COMPOSITES AND THE OPTIMIZATION OF CURE POTENTIAL WITH DIFFERENTIAL SCANNING CALORIMETRY

摘要

The long term performance of a corrosion resistant and high heat resistant Vinyl Ester Glass Fiber Reinforced Composite is ultimately dependant on the manufacturer's ability to achieve a high degree of cure in the finished composite. A high degree of cure insures the finished part will have the service life and achieve the optimal capabilities of the composite. A correlation of the degree of cure, as determined by Differential Scanning Calorimetry (DSC) to the physical properties and the corrosion resistant properties of vinyl ester based composites is shown. A discussion of the suitability of corrosion resistant composites manufacturers to utilize DSC to both insure a very high degree of cure and to assure the customers that they accomplished a high degree of cure in the composite parts they are purchasing so that both the explicit and the implicit design of the composite were achieved is presented. GFRP laminates were made under a variety of conditions to achieve different degree of cures. The degree of cure was determined using DSC. The physical properties: Barcol hardness, flexural strength and modulus, tensile strength and modulus, tensile elongation, heat distortion temperature, glass transition temperature (T_g) and water absorption were measured on GFRP laminates. The vinyl ester/glass laminates with various degrees of cure were immersed into different corrosive media to study the effect of the degree of cure on the corrosion resistance of the panels. This study showed that a high degree of cure yielded better mechanical and corrosion resistance properties. An example of how DSC has been used by a sophisticated manufacturer of corrosion resistant composites to monitor and improve the degree of cure in composites is shown.