The purpose of this research was to study hot-melt adhesives from natural rubber (Standard Thai Rubber 20 STR 20). In order to improve the adhesion and melting properties of hot-melt adhesive to get the best glue formula from STR 20 the ethylene vinyl acetate content (EVA) paraffin wax (Wax) and petroleum resin (Resin) were varied from 25 50 100 125 and 150 phr (Part Per Hundred Rubber). It was found that the best adhesive formulas consisted of 100 phr of STR 20 25 phr of wax 150 phr of EVA and 150 phr of resin. For preparing hot-melt adhesive first the wax was heated and maintained at 160-170 ºC then cut the STR 20 into small pieces and slowly added the rubber into the melted wax until the rubber was completely melted. And then added resin and EVA and cooled to room temperature finally the results show that hot-melt adhesive was dark brown hard and odorless smooth texture and easy to melt with 514±14 centipoises of Viscosity at 150 ºC 82.49±1.4 lbf/in2 of shear strength and 2.06±0.02 kN/m of cleavage peel strength.

In this study natural rubber latex/chitosan (NRL/CT) composites were prepared by latex mixing. The effects of chitosan on latex properties and physical Properties of NRL/CT composite films were focused. It was found that there was no significant change in the latex properties with increasing CT content. Increasing CT contents of 0.5 to 8.0 phr caused the rising of 300 % modulus of the NRL/CT composite whereas the opposite trend was found for tensile strength and elongation at break. The antimicrobial efficacy of the chitosan-incorporated rubber was slightly enhanced from that of the non-chitosan rubber. By comprehensive consideration CT content suitable for antibacterial gloves according to Thai industrial standards (TIS 1056-1: 2013) was 1 phr. For other latex products that require high modulus and antibacterial activity such as tubing pillow foam rubber nipple and catheter CT could be used at higher contents from 2 to 4 phr.