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Water sorption and diffusion in starch/polyolefin blends
Author(s) -
Willett J. L.
Publication year - 1995
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.760351409
Subject(s) - low density polyethylene , crystallinity , materials science , high density polyethylene , starch , sorption , polyolefin , polymer chemistry , masterbatch , diffusion , methyl acrylate , polyethylene , chemical engineering , copolymer , composite material , polymer , organic chemistry , thermodynamics , chemistry , physics , adsorption , layer (electronics) , nanocomposite , engineering
The kinetics of water sorption by starch filled polyolefins has been investigated using blends of commercial starch masterbatch with low density polyethylene (LDPE), high density PE (HDPE), and copolymers of ethylene with methyl acrylate (EMA), ethyl (EEA), AND n‐butyl acrylate (EBA). Transient state diffusion coefficients (D) of water in the blends were determined using Fickian analysis of the initial stages of the sorption isotherms. Measured D values were several orders of magnitude lower than values reported for either pure starch of LIDPE by various investigators. Resin effects on D were on the order D HDPE < D LDPE ≪ D EBA < D EEA < D EMA . The resin effects diminished as the starch content increased. The lower magnitude of D in the blends relative to pure LDPE was attributed to the sorption of water by the dry starch particles, in a manner similar to dual‐mode sorption in glassy polymers. Copolymer effects were consistent with reduction in crystallinity caused by the comonomers. The dependence of the diffusion coefficient on starch content was not described by mixing models of heterogeneous systems of percolation theory.