SILANE COUPLING AGENTS FOR SILANE-TREATED MINERAL REINFORCED ENGINEERING THERMOPLASTICS.

General remarks related to the role of coupling agents employed for enhancement of adhesion between fillers and resin matrix in mineral-reinforced plastics are followed by a description of an experimental investigation in which the effect of silane compound treatment of fillers on strength properties of reinforced thermoplastics was studied. The thermoplastics used in this work were nylon 6, nylon 6/6, and polybutyleneterephthalate. The minerals used as fillers for these thermoplastics were glass beads, naturally occurring silica, and high-aspect ratio mica. The minerals were first treated with silane using either a dry blending or slurry process. It is demonstrated that each of the minerals tested improved the flexural and tensile strength of nylon and PBT, particularly under wet conditions. Flexural modulus, for a given mineral, was little changed. Modulus proved to be primarily a function of the particular mineral chosen, and not of the silane treatment. The silane treatment also noticeably improved processability of the composites. Economic advantage of the use of the filled engineering thermoplastics is indicated.