Accession Number : ADA263241


Title :   Gas Permeability of E/EP Semicrystalline Diblock Copolymers


Descriptive Note : Technical rept.


Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMICAL ENGINEERING


Personal Author(s) : Kofinas, P ; Cohen, R E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a263241.pdf


Report Date : 14 Apr 1993


Pagination or Media Count : 30


Abstract : Gas permeability coefficients P for several gases (He. CO2, CH4, 02, N2) were measured at 25 deg C in a series of semicrystalline diblock copolymers of poly(ethylene)/ poly(ethylene-propylene) (E/EP). A simple model is presented describing the gas transport in these polymer systems. It predicts the permeability of a randomly oriented spherulitic diblock specimen from the permeabilities of the individual lamellar regions of the copolymer. Model predictions were in excellent agreement with the experimental data. The upper bound (lamellae aligned in parallel with respect to the permeation direction) and lower bound (series lamellar align models were calculated and compared to a limited amount of corresponding experimental data on oriented specimens.... Gas transport, Block copolymers, Semicrystalline polymers.


Descriptors :   *PERMEABILITY , *BLOCK COPOLYMERS , *GASES , *ETHYLENE , EXPERIMENTAL DATA , PREDICTIONS , COEFFICIENTS , TRANSPORT , PROPENES , REGIONS , CRYSTALS , MODELS , POLYMERS


Subject Categories : Physical Chemistry
      Polymer Chemistry
      Crystallography


Distribution Statement : APPROVED FOR PUBLIC RELEASE