Concentration profiles were analyzed by measuring refractive index profiles. Such profiles depend not only on the diffusion conditions (temperature, time, kind of solvent, concentration), but also on the conditions of solvent desorption from the polymer (temperature, pressure, solvent, and additive volatilities). In particular, poly(methyl methacrylate) (PMMA) samples modified in an outer shell by zinc chloride carried by methanol are considered. The interferometric technique is a useful tool for the characterization of transparent samples treated in the outer shell by diffusion technique. It is possible to determine the amount and distribution of the residual solvent, the depth of the modified layer, and the additive concentration profile. It is possible to change these characteristics of the treated shells, varying the process conditions such as time and temperature of diffusion and of solvent desorption, or the concentration of the diffusion baths. The characterization of the concentration profiles leads to a better understanding of the action mechanism of the additives and of the manufactured product properties as a consequence of the additive penetration.

ADDITIVES IN TRANSPARENT GLASSY POLYMERS: CONCENTRATION PROFILES OBTAINED BY SOLVENT DIFFUSION TECHNIQUE.

CARFAGNA, COSIMO;
1984

Abstract

Concentration profiles were analyzed by measuring refractive index profiles. Such profiles depend not only on the diffusion conditions (temperature, time, kind of solvent, concentration), but also on the conditions of solvent desorption from the polymer (temperature, pressure, solvent, and additive volatilities). In particular, poly(methyl methacrylate) (PMMA) samples modified in an outer shell by zinc chloride carried by methanol are considered. The interferometric technique is a useful tool for the characterization of transparent samples treated in the outer shell by diffusion technique. It is possible to determine the amount and distribution of the residual solvent, the depth of the modified layer, and the additive concentration profile. It is possible to change these characteristics of the treated shells, varying the process conditions such as time and temperature of diffusion and of solvent desorption, or the concentration of the diffusion baths. The characterization of the concentration profiles leads to a better understanding of the action mechanism of the additives and of the manufactured product properties as a consequence of the additive penetration.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/568547
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