Non-viscoelastic Alloy by Reactive Blending of Nylon with Poly(ethylene-co-glycidyl methacrylate)
by Daisuke SATO(1), Yuji KADOWAKI2), Junya ISHIBASHI(2), Sadayuki KOBAYASHI(1) and Takashi INOUE(2)
(1) Plastics Research Laboratory, Chemicals Research Laboratories, Toray Industries, Inc., Nagoya 455–8502, Japan
(2) Department of Polymer Science & Engineering, Yamagata University, Yonezawa 992–8510, Japan
__________________________________________________________________________
Polyamide (PA) was blended with a reactive polyolefin, poly(ethylene-co-glycidyl methacrylate), using an extremely long (L/D100, L:
screw length, D: screw diameter) twin-screw extruder. The reactive blending yielded a unique morphology of the sub-m m polyolefin particles in which 20 nm PA micelles were occluded. It implies that the in situ-formed graft
copolymer was pulled in the
dispersed particles. The blend showed ultra-high toughness (non-break at Izod impact test) and non-viscoelastic tensile property: the higher deformation rate led to the lower modulus and the larger elongation at break. In the tensile stress–strain curve, the sharp yielding point characteristic to crystalline polymer was hardly seen and the necking stress was maintained almost constant without strain hardening. It suggests a potential application for the energy absorbing car parts, to be friendly for pedestrian and driver.
The reactive blending of dissimilar polymers yields block or graft copolymer. By an emulsifying effect of the in situ-formed copolymer, the morphology could be tuned up; i.e., the size of dispersed particles can be reduced down to sub-m m to optimize the material properties. The copolymer may improve the adhesion between the two phases. Then, the material properties could be improved. It may be a commonly accepted story for the ambiguous but convenient term "compatibilization". Another interfacial behavior recently found is the pull-out of the in situformed copolymer by the external shear forces1–3). It is schematically shown in Figure 1. The pull-out takes place even at the early stage of reactive blending at which dispersed particles are large; e.g., the diameter is the order of 10m m. By the pull-out, 10 nm micelles are dispersed in the matrix.
e-Journal of Soft Materials, Vol. 3, pp. 9–13 (2007)
http://www.jstage.jst.go.jp/browse/ejsm/3/0/_contents
More abstracts about the Non-viscoelastic Alloy by Reactive Blending of Nylon with Poly(ethylene-co-glycidyl methacrylate)