Nanostructured Polyamide by Reactive Blending. 1. Effect of the Reactive Diblock Composition

Abstract

Reactive blending of phthalic anhydride end-capped polystyrene-b-polyisoprene diblock (PSb-PIP-anh) with 80 wt % of polyamide 12 (PA12) results in the very rapid formation of a PS-b-PIP-b-PA triblock copolymer, which self-assembles with formation of characteristic nanoobjects, within the polyamide matrix. For instance, a vesicular nanostructure is formed in the particular case of a symmetric, lamellarforming diblock copolymer. This morphology actually complies with the lower curvature possible for ABC lamellae diluted in a continuous C phase under shear. In contrast, when the diblock composition is typically asymmetric (at constant molecular weight), vesicles disappear in favor of a core-shell morphology with a cucumber-like suborganization. This spontaneous nanostructuration of the PA12 matrix is quite general. Indeed substitution of an amorphous primary amine end-capped styrene/acrylonitrile random copolymer (SAN-NH 2) for PA12 results in exactly the same phase morphology upon reactive blending with PS-b-PIP-anh.

Tough polyamide 6/core–shell blends prepared via in situ anionic polymerization of ε‐caprolactam by reactive extrusion

“…To overcome this problem, a core–shell morphology, which consists of a rigid core and a soft shell, rather than pure low modulus modifiers, has been used to impart a substantial toughening to the matrix while keeping rigidity reasonably high. Generally, the formation of core–shell structure in toughened PA6 blends was by melt compounding PA6 with rubber and a stiff polymer, or with prior‐prepared end‐functional block copolymers . The difficulty is the formation of effective core–shell structures due to the low diffusion rates of viscous rubber in the ternary blend and the micellization or self‐assembly effect of block copolymers in the copolymer toughened system.…”

Fabrication of nanostructured polycarbonate/poly(methyl methacrylate) blends with improved optical and mechanical properties by high‐shear processing

“…Microphase‐separated block copolymers [2–4] and polymer nanocomposites with homogeneously dispersed nanofillers [5–9] are two typical well‐investigated heterogeneous transparent polymeric materials. On the other hand, considerable attention has also been paid to the blending of a homopolymer with a block copolymer containing blocks similar to the homopolymer [10–15]. It was shown that the one block of the copolymer can be incorporated into the homopolymer and the other blocks form a nanostructured phase due to the microphase separation.…”

Reactive compatibilization of poly(methyl acrylate‐ran‐acrylonitrile)/poly(ethylene) blends through amine–anhydride coupling

“…31 One key difference that may explain our results is that the amine on the p-amino styrene monomer was an aniline, which does not react as quickly as a primary aliphatic amine. [77][78][79] With slower coupling rates, the interface cannot be stabilized as rapidly, leading to slightly larger final domain sizes.…”