S. Hayashi, T. Kajiyama, M. Takayanagi
May 1, 1981
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0
Influential Citations
5
Citations
Journal
Polymer Journal
Abstract
Poly(spiro[2,4]hepta-4,6-diene) (PSHD) is an amorphous random copolymer composed of 1,2 and 1,4 units, whose sequences form semi-rigid (intermediate between rigid and flexible) and rigid chains, respectively. The density of PSHD decreases by increasing the fraction of 1,4 units (F1,4). The aggregation state of PSHD chains as a function of F1,4 was investigated by X-ray diffraction and electron microscopic observation. A heterogeneous amorphous state composed of densely and loosely packed aggregates changes to a more homogeneous one with increasing F1,4. Permeabilities of H2, He, O2, Ar, and N2 gases through PSHD membranes with varying F1,4 were measured. Permeability and diffusion coefficients for these gases exhibit minima in the vicinity of F1,4=0.7. This fact can be explained by a combination of chain packing and heterogeneous aggregation of molecular chains.