| abstract |
Integrally blended additives, consisting of a ternary mixture of gamma methacryloxypropyl trimethoxysilane, trimethylolpropane triacrylate and a siloxaneoxyalkylene block copolymer, in the absence of dicumyl peroxide do not consistently improve the mechanical properties of mica filled polyolefins. This is especially true under "low shear" melt processing conditions e.g. employing a conventional screw design in a single barrel extruder. However, when the ternary mixture is combined with a small amount of dicumyl peroxide (neat or dissolved in vinyltrialkoxy silane) there is a consistent improvement in composite mechanical properties above that of the composites containing the ternary mixture alone and in comparison to mica filled polyolefin composites without any additive or composites containing the peroxide alone. Furthermore, thermal aging tensile strength retention is improved in mica filled polypropylene composites containing the ternary mixture combined with dicumyl peroxide. |