Preparation and Properties of Phenol Formaldehyde Poly(Vinyl Alcohol)Resin as Fibre-Reinforced Film Adhesive
Lim, Chee Siong (2004) Preparation and Properties of Phenol Formaldehyde Poly(Vinyl Alcohol)Resin as Fibre-Reinforced Film Adhesive. Masters thesis, Universiti Putra Malaysia.
This study aims to evaluate the chemical composition, physical and mechanical properties of fibre-reinforced composite via synthesis of resole fibre-reinforced phenolic resin binded and cured under heat and pressure to the outside metal faces. Two types of resin; phenol formaldehyde resin and poly(vinyl alcohol) resin were blended and applied on the paper’s surfaces (MG Craft Paper GSM: 50 Ribbed) and then arranged in an alternate manner for the adhesion of both surfaces resin. A series of various phenolic resin/poly (vinyl alcohol) blend compositions were prepared through solution casting technique and characterization was done through infrared, differential scanning calorimetry, thermogravimetry analysis, viscosity measurement, tensile strength and Young’s modulus. Prepared specimen was cured for pre-press stage for 72 hours under pressure of 25 kg cm-2 at room temperature before undergoing hot press step. The compounded samples were then hot pressed at temperature 200 ± 5 °C and pressure 100 kg cm-2 for about 30 minutes and setting duration was taken after temperature setting was achieved. After cooling, the samples were tested for various analytical and mechanical assessments such as flexural strength and flexural modulus in accordance with ASTM Standard D790-98a. The samples were also characterized for density and moisture content, and these procedures were repeated for different parameters; curing time, curing temperature, temperature setting and pressure setting. FT-IR study indicated that the polymer blending lead to formation of methylol groups of phenolic resin and double bonding of PVA towards strong internal bonding with paper surface, polymer blending demonstrated low resistance in miscibility via DSC, the composite displayed high shear thinning and high yield stress which resemblance liquid-like flow behaviour determined by viscometer. TGA detected the polymer blend is dispensed to the die and it has the ability to form chemical bond with the coated substrate. Phenolic formaldehyde/poly(vinyl alcohol) blending at ratio of 5/95 showed the highest tensile strength (12705.2 Pa) and Young’s modulus (355.7 Pa). The density of the fibre-reinforced composites with aluminium sheets produced in this study was found to be a maximum at 1.74 × 103 kg m-3 (Ratio = 100/0) and pure PVA exhibit the highest moisture content with 19.19 %, this would affect the resistance to cracking of the resulting product. However, fibre-reinforced composite with high composition loading of PF/PVA = 60/40 demonstrated the highest flexural strength and flexural modulus. Meanwhile, curing time, curing temperature, temperature setting and pressure setting of 96 hours, 25 °C, 200 °C and 120.0 kg cm-2 respectively was found to be the most economical and optimum condition for formation of fibre-reinforced composite, with excellent structural strength.
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