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In this work, we investigated the effect of carbon black (CB)-loading on the miscibility of poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) blends using the CB particle as a self-diagnosing probe. The mobility of the CB particles both in homogeneous and PVDF/PMMA blend matrices was real-time monitored through in situ recording the variation of electrical resistivity with time during...
Dynamic electrical analysis shows that at high temperatures (above the glass transition temperature), the electrical properties of polymethyl methacrylate are strongly influenced by space charge. In this paper we present an study of space charge in this material and its conductive properties by dynamic electrical analysis, using the electric modulus formalism. The complex part of the electric modulus...
The crack healing of poly(methyl methacrylate)(PMMA) treated with a solvent mixture of methanol and ethanol was studied. The mass transport of the solvent mixture in PMMA is anomalous; it is mixed Case I and Case II transport. The data of mass transport can be analyzed by Harmon's model. It was found that the activation energies of Case I and Case II transport of mixture are equal to the summation...
A series of interval absorption runs in the system poly(methyl methacrylate)–methyl acetate vapor at 30°C exhibiting non-Fickian behavior are presented. The relevant diffusion and viscous relaxation processes were studied separately by kinetic analysis of the first and second stage of two-stage sorption curves, respectively. Both processes were found to be much slower than that observed by Kishimoto...
NMR spectroscopy confirmed the existence of a C-Br bond at the terminal chain end of low molecular weight poly(methyl methacrylate) (PMMA) produced by atom transfer radical polymerisation (ATRP). Polymer was prepared using the heterogeneous Cu(I)Br/2,2'-bipyridine (bpy) catalyst with ethyl-2-bromoisobutyrate used as the initiator. This structural feature was not evident in the matrix-assisted laser...
In this paper, we investigate poly(methyl methacrylate) (PMMA)-modified epoxy thermoset based on DGEBA before and after curing of the epoxy with various aromatic amines by means of different techniques: Differential Scanning Calorimetry (DSC), Size Exclusion Chromatography (SEC), Infra-Red Spectroscopy (FT-IR), Dynamic Mechanical Analysis (DMA) and Transmission Electron Microscopy (TEM). The DSC analyses...
This paper reports on the anionic synthesis of poly(methyl methacrylate) chains end-capped by cyclic anhydride. The method is based on the chemical derivatization of a precursor tert-butyl diester end-group. Compared to the thermal modification, which was previously used, this method allows intermolecular coupling and polymer degradation to be avoided. But up to now, the final anhydride content remains...
Fast transient fluorescence technique (FTRT) was used to measure pyrene (Py) lifetimes during dissolution of glassy polymer, which is formed by free radical polymerization of methyl methacrylate (MMA), and Py was introduced during polymerization as a fluorescence probe to monitor swelling and dissolution. The dissolution process of poly(methyl methacrylate) (PMMA) glass was performed in chloroform...
We describe the radical dispersion polymerisation of methyl methacrylate in supercritical carbon dioxide using a poly(dimethylsiloxane) monomethacrylate as the stabiliser. Initial observations showed that in the absence of efficient stirring, acceptable yields, molecular weight and particle morphology for PMMA were observed. However, efficient stirring of the reaction mixture was found to substantially...
The coil-globule transition behaviour of poly(methyl methacrylate) has been studied in isoamyl acetate by using the dynamic light scattering technique. The dimensions of the polymer show smooth and continuous contraction below θ temperature (61.0 o C). The hydrodynamic size of PMMA in isoamyl acetate (M w =3.3x10 6 gmol -1 ) decreases to 41% in an unperturbed state...
A very simple method to obtain unperturbed dimensions from measurements of just one sample of a polydisperse polymer, using differential refractive index and multiangle laser light scattering detectors in size exclusion chromatography is presented. Poly(methyl methacrylate)s of broad molecular weight distribution have been measured, in a good solvent, in order to obtain the scaling law between the...
Copolymers of methyl methacrylate (MMA), and the methacrylic monomers derived from salicylic acid, 2-hydroxy-4-methacrylamidobenzoic acid (4-HMA), and 2-hydroxy-5-methacrylamidobenzoic acid (5-HMA), were prepared by free radical polymerization in N, N-dimethylformamide, DMF, solution at 50°C using 2, 2′-azobisisobutyronitrile (AIBN), as initiator. Fineman–Ross and Kelen–Tüdos linearization methods,...
A random copolymer of methyl methacrylate and 5.7mol.% of acrylic acid has been neutralized by zinc cation to different extents in order to study the effect of zinc carboxylate pendant groups on the miscibility of poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride) (PVDF). The interaction parameter (χ) has been calculated from the experimental depression of the PVDF melting point. χ is...
Solid state 13 C n.m.r. measurements were carried out on polymer networks based on methyl methacrylate and diethylene-glycol-bis-allyl-carbonate. Several relaxation time parameters (rotating frame and laboratory frame proton and carbon relaxation times) were determined. Cross-polarisation times and carbon relaxation times were interpreted based on the changes in the molecular motion during...
A model based on the concept of fractional calculus is proposed to predict the viscoelastic behaviour of amorphous polymers in the temperature range from T g - 190 o C to T g + 25 o C. Poly methyl methacrylate (PMMA) has been chosen as a model amorphous polymer. PMMA has been studied by dynamic mechanical spectrometry and the experimental data have been compared with...
Methyl methacrylate monomer was graft-copolymerized on a polyethylene (PE) surface and the tethered poly(methyl methacrylate) (PMMA) chains were spin-labelled to study the molecular motion of the PMMA chains by electron spin resonance (e.s.r.). Molecular mobility of the PMMA chains is strongly affected by physical structures of both PE and PMMA phases. For example, the transition temperature of molecular...
Catalytic chain transfer polymerization of benzyl methacrylate leads to a mixture of poly(benzyl methacrylate) macromonomers. Benzyl methacrylate dimer macromonomer has been isolated as a pure compound and used as a radical addition fragmentation chain transfer agent. This results in poly(methyl methacrylate) with both α and ω terminal benzyl methacrylate units. Catalytic hydrogenation of α,ω-benzyl...
In order to study the effect of particle size on the toughening behaviour of rubber-toughened poly(methyl methacrylate) (PMMA), a systematic model study has been carried out using core-shell type particles, made up of a poly(n-butyl acrylate) (PBA) core and a PMMA outer shell. Two different fracture tests, i.e. a three-point bending test for the evaluation of the fracture toughness (K IC...
Nuclear Reaction Analysis is used to study the interdiffusion of deuterated and protonated poly(methyl methacrylate). The diffusion process is found to follow the fast theory predictions and self diffusion is seen to be governed by pure reptation with no evidence of constraint release. The diffusion coefficients scale with temperature according to the Williams-Landel-Ferry equation and are in good...
It is well known that the miscibility of dissimilar polymers with high molecular weights arises from specific interaction, such as hydrogen bonding. To discuss the influence of the interaction on a side group rotation and main chain motion of poly(methyl methacrylate) (PMMA) in PMMA/poly(vinylidene fluoride) (PVDF) blends, we investigated the dielectric loss as a function of frequency f. ...
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