DuPont MULTIBASE™ MB50-008 Masterbatch is a pelletized formulation containing 50% of an ultra-high molecular weight (UHMW) siloxane polymer dispersed in styrene acrylonitrile (SAN) carrier.
It is designed to be used as an additive in most styrenic compatible systems to impart benefits such as processing improvements and modification of surface characteristics. Liquid siloxane plastic additives have been used for several years to improve the lubricity and flow of thermoplastics. They are effective in this role although some difficulties have been experienced in the incorporation of liquids into thermoplastic melts without the use of specialized equipment. It has also been difficult to produce masterbatches with greater than 20% liquid siloxane because of processing difficulty and bleed problems.
The DuPont MULTIBASE™ MB Series Masterbatches address these problems by supplying a high concentration of an ultra-high molecular weight (UHMW) siloxane as a dispersion in a dry pellet form in a variety of thermoplastics.
APPLICATIONS
Additive in styrene-acrylonitrile compatible systems
BENEFITS
When added to SAN or similar thermoplastics at 0.2% to 2.0%, improved processing and flow of the resin is expected, including better mold filling, less extruder torque, internal lubrication, mold release and faster throughput. At higher addition levels, 2% to 10%, improved surface properties are expected, including lubricity, slip, lower coefficient of friction, and greater mar and abrasion resistance.
The DuPont MULTIBASE™ MB Series Masterbatches are expected to give improved benefits compared to conventional lower molecular weight siloxane additives, e.g., less screw slippage, improved release, a lower coefficient of friction, fewer paint and printing problems, and a broader range of performance capabilities. The addition of 2% polydimethylsiloxane (PDMS) gives a significant reduction in wear rate, as shown in Table 1. While this data was obtained with a lower molecular weight siloxane additive, similar results are expected when DuPont MULTIBASE™ MB50-008 Masterbatch is added to styrenics (SAN, ABS, polystyrene). Additionally, use of ultra-high molecular weight siloxane additives give very little loss in paintability with a waterborne paint system