增容剂NBR对SBR／HDPE／PVC共混物力学性能的影响

EFFECTS OF COMPATIBILIZER NBR ON MECHANICAL PROPERTIES OF SBR/HDPE/PVC BLENDS

The effects of compatibilizers chloroprene rubber ( CR),chlorinated polyethylene (CPE) and nitrile-butadiene rubber (NBR) on the mechanical properties of SBR/HDPE/PVC blends were studied . The compatibilizers can increase the mechanical properties of blends significantly and NBR with less bounded acrylonitrile are better compatibilizers among them . Adding 4 phr NBR to the blends of SBR/HDPE/PVC =56/20/20 (mass ratio ), tensile strength of the blends increases from 8.1 MPa to 13.9 MPa , tear strength from 24.5 kN/m to 32.7 kN/m ,while elongation at break and permanent set decrease slightly . Varying NBR amount from 2 to 14 percent , mechanical properties of the blends change slightly .The compatibilizer NBR can enhance the interaction between phase interfaces and promotethe dispersion of multiphase system . This is due to that the polarity and solubility parameter of NBR tend to medium between blend components , NBR contains both segments rich in acrylonitrile compatible with PVC and segments rich in butadiene compatible with HDPE and SBR , these segments can diffuse into compatible phases respectively at mixing temperature , and they are fixed or crosslinked while cooling and co-curing.The strong interaction forms between phase interfaces and spreads stress , thus makes the blends with compatibilizer NBR have good mechanical properties .