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Effect of viscosity variation with temperature on the compounding behavior of immiscible blends
Author(s) -
Ratnagiri Ram,
Scott Chris E.
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11576
Subject(s) - compounding , materials science , polymer blend , viscosity , polycarbonate , composite material , polybutylene terephthalate , phase (matter) , polyethylene , thermodynamics , polymer , organic chemistry , copolymer , chemistry , polyester , physics
Morphology development in the compounding of immiscible blends depends on a number of material properties and process conditions. In this work, different model blend systems are considered to outline the effects of the relative transition temperatures and viscosities of the blend components. We focus on the evolution of blend morphology, specifically phase continuity. A framework based on these factors is presented for analyzing the compounding behavior of immiscible blend systems. With the minor component at 10 wt%, it was found that phase inversion during compounding occurred in blends with a viscosity ratio of less than 0.2, independent of the relative transition temperatures. It was shown that in these constant mixer temperature runs, the torque trace was not a completely reliable indicator of phase inversion. When a temperature ramping program was used, the lower melting point component formed the continuous phase initially, independent of the viscosity ratio. Quantitative measures of the amount of minor component which was continuous at different mixing times were made using selective extraction in a Soxhlet apparatus. Results from compounding runs of polycarbonate/ polyethylene, an amorphous copolyester/polyethylene and polybutylene/polycaprolactone blends are presented.