Thermal Polymerization of Drying Oils

Abstract

changes with time in the numerical values of the three parameters are shown in Fig. 12.These a.c. measurements are far from complete, for they must be taken for most of the materials studied' for d.c. leakage before broad conclusions can be drawn. It will be important to establish, the order in which these materials are arranged in terms of either fractional change in capacitance or maximum dissipation factor and to determine the corresponding values of storage coefficient and relaxation frequency in order to set a frequency limit beyond which humidity has no appreciable effect. ACKNOWLEDGMENT

Polymer Fractionation of Heat-Polymerized Non-Conjugated Vegetable Oils

“…(i) that a material could be quantitatively separated from the oil gels by means of petroleum ether, (2) that this separated material possessed the physical and chemical properties of an insoluble, infusible, cross-linked polymer, ¡J) that it was present in substantial amounts as postulated in the author's theory, and…”

“…The gel samples represented a considerable problem with respect to their fractionation. Three factors were involved: (/) the determination of the specific material causing gelation; (2) the quantitative separation of this material from its absorbed liquid phase; and (d) the fractionation of the liquid phase of the gel.…”

“…On the basis of the experimental data it may in general be said that the heatpolymerization of the noil-conjugated vegetable oils is essentially a stepwise addition reaction involving primary valence bonds, the resulting polymer growth being evidenced in the following four experimentally independent directions: (1) solubility, (2) molecular weight, (3) viscosity, and (. () iodine value.…”

“…A few of the data abstracted from the present work were given in this previous paper, and were used for the purpose of testing the adequacy of the polymerization mechanism advanced by the author. It is the purpose of the present paper (I) to give a general account of the polymerfractionation technique developed and to attempt the theoretical basis for its selectivity, (2) to give a detailed account of the specific procedure used in the fractionation of heat-polymerized linseed and soybean oils at various stages of the reaction, including that of the final stage of gelation, (3) to present the experimental data obtained, and (4) to interpret the data not only from the viewpoint of general polymerization theory and polymer distribution, but more specifically as a means of testing their correspondence to some of the postulates of the author's theory.…”

Progress in the Protective Coatings and Plastics Industries

“…estera are the better known examples of addition polymerization. These vinyl compounds polymerize by a free radical mechanism which involves three stages: (1) an initiation of the free radical of this monomer; (2) the extremely rapid growth of the free radical chain to a very high molecular weight (usually); and (3) a termination reaction which destroys the free radical at the end of the chain. Such vinyl polymers are usually linear, soluble polymers; so a functionality of two is assigned to the vinyl group in Table II.…”