TERNARY BLEND WITH SYNERGISTIC ACTION OF ELASTOMERIC AND RIGID POLYMER INCLUSIONS; COMPARISON OF VULCANIZED AND REACTIVELY COMPATIBILIZED ULTRAFINE RUBBER PARTICLES
I. Kelnar1,*,
J. Kotek1, B.S. Munteanu1, J. Qiao2, and L.
Kaprálková1
1 Institute of Macromolecular Chemistry, Academy of
Sciences of the Czech Republic, Heyrovský Sq. 2, 162 06 Prague 6, Czech
Republic
e-mail: kelnar@imc.cas.cz
2 SINOPEC Beijing Research Institute of
Chemical Industry, Beijing 100013, People’s Republic of China
Polyamide 6/poly(styrene-co-maleic anhydride)/maleated rubber blends exhibit very well balanced mechanical properties, as a result of synergistic influence of a finely dispersed rigid polymer and elastomer particles. The rigid inclusions in fact replace the elastomer by acting as stress concentrators and by a subsequent strain hardening effect; as a result, not only toughness, but also strength is enhanced. Best results are obtained for the size of both rigid and elastomer particles close to 100 nm. This fine structure is achieved by reactive compatibilization, leading to a lowering of stiffness by the negative effect of the in-situ formed compatibilizer on PA6 crystallinity. The use of of vulcanized rubber particles also leads to the ultrafine structure without compatibilization and thus reduction of PA6 crystallinity. As a result, vulcanized rubber particles containing ternary blend represent an alternative to reactively compatibilized blends with higher strength and modulus. The toughness, reduced by lower deformability (limited cavitation) of crosslinked rubber and weaker interfacial bonding, still significantly exceeds value for PA6.