Loading…

The percolation limits for two-phase blends of PMMA and copolymers of styrene and MMA

Phase separation and phase structure growth were studied, in the temperature range 150–220°C, in blends of poly(methyl methacrylate) (PMMA) and random copolymers of styrene and methyl methacrylate [P(S x MMA 1− x )] with x ≧ 0.4. Blends with 0.4 ≦ x < 0.6 are homogeneous at lower temperatures. On...

Full description

Saved in:
Bibliographic Details
Published in:Polymer (Guilford) 1993, Vol.34 (5), p.925-932
Main Authors: Andradi, L.N, Hellmann, G.P
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Phase separation and phase structure growth were studied, in the temperature range 150–220°C, in blends of poly(methyl methacrylate) (PMMA) and random copolymers of styrene and methyl methacrylate [P(S x MMA 1− x )] with x ≧ 0.4. Blends with 0.4 ≦ x < 0.6 are homogeneous at lower temperatures. One-phase films of these blends were cast at room temperature from solution. Granules of all blends with 0.4 ≦ x ≦ 1 were made by extrusion at 180†C. They had a fine two-phase morphology. Isothermal structure evolution was studied with both types of blends. The types of morphology and the structure growth rates were investigated, particularly in late stages where growth proceeds under steady-state conditions. The percolation limits between domain-matrix and cocontinuous morphologies were determined as a function of the incompatibility, χ χ c , which strongly increases with x in the blend series. The percolation range proved to be similar to the spinodal range at low χ χ c , but not at high χ χ c , where cocontinuous morphologies are found in a narrow range only.
ISSN:0032-3861
1873-2291
DOI:10.1016/0032-3861(93)90209-S