Effect of a N,N′‐disubstituted phenylenediamine stabilizer and SB/EPDM compatibilizer on toughness and morphology of blends of pre‐aged polyethylene with high‐impact polystyrene

The effect of a N,N′‐disubstituted 1,4‐phenylenediamine stabilizer and styrene‐butadiene block copolymer (SB)/ethylene‐propylene elastomer (EPDM) compatibilizer on mechanical properties and phase structure of pre‐aged low‐density polyethylene (LDPE; a model of aged recyclate)/high‐impact polystyrene (HIPS) blends was studied. A strong cooperative effect between the stabilizer and compatibilizer on the impact strength and fineness of the phase structure of LDPE/HIPS blends was found. Analysis of chemical reactions assumed to proceed in the system during processing led to the conclusion that improvement in the impact strength and phase structure was accounted for by reactive formation of a LDPE‐SB graft copolymer in a process supported by the presence of the bifunctional amine‐based stabilizer. The mixture of the amine stabilizer with SB/EPDM is a very promising upgrading system for post‐consumer plastic waste containing pre‐oxidized LDPE. J. VINYL. ADDIT. TECHNOL. 12:58–65, 2006. © 2006 Society of Plastics Engineers.