Compatibility in poly(ethylene oxide)–poly(methyl methacrylate) blends

Abstract

SynopsisThe compatibility of poly(ethy1ene oxidehpolflmethyl methacrylate) (PEO-PMMA) blends were examined covering the complete composition range. Up to 20% of PEO content films were transparent and glass transition temperatures were determined by DSC and by refractive index vs. temperature measurements. Only one T, was obtained for these samples and the relationship between T8 and composition has been evaluated. At higher PEO content crystallization took place and the films were opaque. Melting temperatuures of PEO in blends were determined by DSC. Melting point depression was observed for increasing proportion of PMMA and the binary interaction parameter has been calculated. EXPERIMENTALSeveral samples of commercial PEO were used (2, = 4,000, 6,000, and 10,000 from Atlas Industrias Quimicas S.A.; and Bw = 7,500, 14,000, and 18,500 from Polyscience Inc.). PMMA (B, = 6x lo5) was prepared by conventional suspension polymerization.Physical mixtures of PEO of different molecular weights and PMMA covering the whole range of composition were prepared at room temperature as cast films from chloroform solutions. The resulting films were subjected

Volume Relaxation Rate in a-PMMA and a-PMMA/PEO Amorphous Blends

“…For the experiments two basic materials were used: the first was a random copolymer of methyl metacrylate and methyl acrylate denoted a-PMMA (Plexiglas 6N, Röhm GmbH), content of methyl acrylate was determined 6 mol% by 13 …”

“…15,16 In the glassy state, however, phase separation occurs creating amorphous nanoheterogenous structure with an approximate domain size of 20-70 nm. 11,12 The glass transition temperature of PEO was predicted to be in the range of À42 to À72 C, 13,14 which is much lower than T g of PMMA, about 105 C. It means that at room temperature the amorphous phase y To whom correspondence should be addressed (Tel: +420-57-603-1350, Fax: +420-57-603-1444, E-mail: slobodian@ft.utb.cz).…”

“…[8][9][10] When the content of a-PMMA is higher than 70-80%, the blend becomes completely amorphous and shows a single T g dependent on the blend composition. 9,[11][12][13][14] Such blends are considered to be completely miscible in melt. 15,16 In the glassy state, however, phase separation occurs creating amorphous nanoheterogenous structure with an approximate domain size of 20-70 nm.…”

“…6,7 Among various blends a special kind of miscible blends, composed of one amorphous component and the other crystallizable, atactic poly(methyl methacrylate)/poly(ethylene oxide), (a-PMMA/PEO), has been lately extensively investigated. [8][9][10][11][12][13][14][15][16][17][18][19][20][21] The presence of PMMA in blend restricts PEO crystallization, and hence the degree of crystallinity decreases with rising amount of PMMA. [8][9][10] When the content of a-PMMA is higher than 70-80%, the blend becomes completely amorphous and shows a single T g dependent on the blend composition.…”

Influence of Dipole Interactions on Mechanical Behavior of Modified Epoxy Resins

“…In this paper, we used poly ethylene glycol (PEG) and carboxyl-terminated butadiene acrylonitrile (CTBN) to modify DGEBA/methyl hexahydrophalic anhydride (MeHHPA)/benzyl dimethylamine (BDMA) epoxy systems, in these systems, hydrogen bonding is not significant, the main interaction was electrostatic force (dipole interactions), 9,10 and we studied influence of dipole interactions on tensile properties, impact strength, fracture toughness (G IC ), glass transition temperature, and crack resistance test of epoxy resins under thermal shock.…”