Lee P. Witnauer

Vernonia anthelmintica willd. Seed oil and salts of vernolic acid as stabilizers for plasticized poly (Vinyl chloride)

Vernonia anthelmintica seed oil, trivernolin, the main constituent of the oil, barium and cadmium salts of vernolic acid (epoxyoleic acid), and various combinations of the salts have been evaluated as heat and light stabilizers of plasticized poly (vinyl chloride). Evaluation was made at the 1 and 3% levels of the vernonia oil components. Transparent sheets whose color ranged from light amber to colorless were obtained after milling and molding. All compounds studied greatly improved both heat and light stability of the sheets; the 3% stabilizer level gave the better results. In general the stabilizing ability of the compounds studied increased as follows: vernonia oil<trivernolin<barium vernolate< cadmium vernolate and <barium-cadmium vernolate mixtures. Comparisons with 3 commercial stabilizers show that the vernonia oil and derivatives thereof are equal to or better than the comparative commercial controls.

The electric birefringence buildup curve as applied to the determination of the dipole moment of soluble collagen

Abstract Electric birefringence patterns of calfskin corium collagen dissolved in citrate buffer in the acid pH range were made. At high concentrations of collagen, these showed an anomalous electric birefringence pattern which was indicative of time-dependent variations in permanent and induced dipole moments. Measurements of dipole moments showed that when the square wave pulsed electric field is created, permanent and induced dipole moments are in the same direction. This is followed by a progressive decrease in permanent dipole moment with pulse duration, and at high field strength the electric field eventually brings about a reversal in direction between permanent and induced dipole moments. The effect of pH on this phenomenon was studied.

Some effects of electrolytes on collagen in solution

Abstract Since collagen form an aqueous solution only when electrolytes are present, a study of the effects of electrolytes on dissolved collagen was carried out to obtain data which might lead to improved solubilization and fractionation techniques. Salting-out curves of collagen in phosphate buffer solutions were prepared. Dissolved collagen was constituted from phosphate buffer and citrate buffer solutions by various methods and the precipitated fibrils showed a variety of structural forms. Fibril morphology was related to solution history and an attempt was made to show that electrolytic environment influenced the aggregation of collagen molecules into organized structures through ion binding and electrostatic interaction.

Vernolic acid esters as plasticizers for polyvinyl chloride

The methyl, propyl, butyl, isobutyl, hexyl, cyclohexyl, octyl, and 2-ethylhexyl esters of vernolic (epoxyoleic) acid, a naturally-occurring epoxy acid, were prepared and evaluated as plasticizers of polyvinyl chloride. All the esters showed good compatibility. The data indicated that they are excellent low temperature plasticizers having Tf temperatures below −50C. They also have the added advantage of greatly increasing the heat stability of the polyvinyl chloride and improving the light stability. The results are compared with DOP and other epoxy-containing plasticizers now being used commercially. These esters should not only be useful as primary plasticizers but also in combination with other plasticizers as plasticizer-stabilizers.

Epoxy resins from fats. I. Epoxidized glycerides cured with phthalic anhydride

Summary and ConclusionEpoxy resins were made from phthalic anhydride and the following expoxidized fatty glycerides: neats-foot oil, lard oil, triolein, soybean oil, perilla oil, and trilinolein. Some physical properties of these resins were measured and tabulated.It has been shown that heat-distortion temperature, tensile strength, and modulus of elasticity increase with the unsaturation of the glyceride precursor of the epoxy intermediate.

The effects of an electric field on soluble collagen

Electric birefringence decay curves of collagen suspended in aqueous buffered media were plotted as functions of pulse width and amplitude. They were then resolved into two components by means of an analog simulator. When these data were combined with the results of repeated pulsing, it was shown that an electric field promotes aggregation of collagen, although the variety of aggregate sizes falls within a fixed range. Observations of electric birefringence of dissolved collagen preparations as a function of ionic strengths tend to indicate that the bonding that occurs in an electric field is electrostatic.

Esters of hydroxystearic acids as primary low-temperature plasticizers for a vinyl chloride—Vinyl acetate copolymer

SummaryThirty-one acyloxy or aryloxy esters prepared from hydroxystearic acids have been evaluated as plasticizers for a vinyl chloride-vinyl acetate copolymer (95∶5). Many of them were found to be primary plasticizers, having outstanding low-temperature performance when employed at the 35% level. Formulations with these compounds compared quite favorably in tensile properties with those containing the di-2-ethylhexyl esters of phthalic, sebacic, azelaic, and adipic acids. Volatility losses were similar to those of the four di-2-ethylhexyl esters. The loss of plasticizer through migration was equal to or less than that from compositions containing the esters of sebacic, azelaic, and adipic acids but was greater than that of the phthalate ester.A mechanistic scheme of plasticizer-polymer interaction has been presented, proposing that the rate of diffusion of plasticizer through the polymer mass is a controlling factor in both good low-temperature performance and the resulting high migration losses. Methyl esters, some aromatic esters, and esters containing three or more polar centers have improved permanence but show a more rapid change in torsional modulus as the temperature is lowered during the determination of the Clash-Berg stiffening temperature.

X-ray diffraction and melting-point studies on some long-chain sulfur-containing acids

SummaryX-ray diffraction powder data and melting points have been determined on three series of crystalline long-chain sulfur compounds, namely 11-(n-alkylsulfonyl)-undecanoic acids; 11-(n-alkylsulfinyl) undecanoic acids; and 11-(n-alkylthio) undecanoic acids; where R is a selected alkyl group from methyl through undecyl. In the sulfone series the long spacings increase regularly with the increase in the number of carbon atoms in R. In contrast to unsubstituted longchain fatty acids the odd and even members fall on the same line in the plot of long spacings against carbon atoms in R. As expected, a nonalternation in melting point is observed. In both the sulfoxide and sulfide series two nonparallel straight lines are obtained, one for the even-membered and one for the odd-membered compounds, in the plot of long spacings against carbon atoms in R. As expected, the melting points of the sulfoxides and sulfides show an alternation. Polymorphism is more evident and complicates the interpretations most in the sulfide series and least in the sulfone series. all three series of compounds crystallized as tilted dimers.

Evaluation of butyl stearate, butyl oleate, butyl ricmoleate, and methyl lmoleate as poly(vinyl chloride) plasticizers

An investigation of butyl stearate, butyl oleate, butyl rieinoleate, and methyl lmoleate was made to determine the extent of their compatibility with poly(vinyl chloride) and their plasticizing effects on the physical, properties of the resulting molded sheets. These monoesters were evaluated as the sole plasticizer and in combination with DOP. The results showed the materials to have limited compatibility in general, being less than 10% of the total mix. In combination with DOP these compounds were found to improve the plasticizer efficiency, color, low temperature flexibility, and heat stability of the molded poly (vinyl chloride) sheets over those containing DOP as the sole plasticizer. Tensile strength, per cent elongation, and light stability properties were essentially comparable to those found for pure DOP.