Methacrylate Type Research Articles

Problems of diffusion for polymethyl methacrylate/water systems

In our research two types of polymethyl methacrylate have been used: theM-type with relatively high contents of monomer, and theT-type with small amounts of unpolymerisated monomer.

Viscoelasticity of Polymethyl Methacrylate—an Experimental and Analytical Study

Abstract This paper is concerned (a) with a presentation of static tensile stress-strain data under many different experimental conditions on several types of methyl methacrylate, together with an empirical equation to describe them, and (b) with an attempt to correlate the static behavioral characteristics of two varieties of methacrylate by means of an extension of the Boltzmann-Volterra theory of the elastic aftereffect to an extent that facilitates the prediction of creep and constant-strain-rate curves from stress-relaxation data to within an error acceptable for engineering purposes.

Some comparisons of self-curing and heat-curing denture resins

D URING the past year or more there has been a continued and growing interest in the self-curing resins for denture base applications. The general adoption of the heat-cured methyl methacrylate type of denture base resin by the profession and patient gives a standard by which comparisons in properties of other types of resins can be made. To this time, only limited reports of studies are available for making these comparisons, and further studies should contribute much to the understanding of these cold-cured materials. The cold-cured or self-cured type of resins lend themselves well to comparison with properties of the heat-cured type by giving consideration to the chemical nature of the two types of materials. It is now common knowledge that chemically the chief difference between the two is the method of initiation or activation of the polymerization process. One is accomplished by the presence of a small amount of an appropriate chemical, while th’e other is brought about by the application of heat to the plastic mass. Fundamentally the two types are therefore quite similar in basic composition except. for minute differences in essential ingredients. It is to be reasoned, therefore, that the self-cured resins for dentures may have physical and mechanical properties as good as, but generally no better than, the heat-cured resins. As is often true, however, with two substances that are very similar in nature, one may lend itself better to certain adaptations or techniques than another. This may be a most favorable feature of the self-curing resins for denture bases.