title: Characterisation of the mechanical properties of polymer films formed from aqueous polymer dispersions by creep testing.
abstract: The mechanical properties of films formed from an aqueous dispersion of polymethlymethacrylate (Eudragit NE30D) and as mixture with an aqueous dispersion of ethylcellulose (Aquacoat ECD30), have been assessed by applying creep tests at different temperatures, using a dynamic mechanical analyser. In the region of linear creep, the film prepared from 100% Eudragit was far less elastic than when 60% Aquacoat was present. In this region, when the applied stress was doubled, the strain response was doubled. In the non-linear region of behaviour, there is clear evidence that the mixed film is more elastic than the film containing only Eudragit.
authors.affiliation: The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N1AX, UK.
authors.forename: S V
authors.initials: SV
authors.lastname: Lafferty
authors.forename: J M
authors.initials: JM
authors.lastname: Newton
authors.forename: F
authors.initials: F
authors.lastname: Podczeck
mesh_terms: D004548:Elasticity; D005079:Excipients; D008567:Membranes, Artificial; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D005079:Excipients; D008567:Membranes, Artificial; D011108:Polymers; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer