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The accelerated aging of unplasticized Cellophane film specimens was conducted at tempe:atures ranging from 80 to 150 °C in a dry, forced-air convection oven for various periods of time. Colorimetric evaluation showed increasing discoloration which could be partially reversed by rinsing in deionized water. The infrared spectra of samples aged within this temperature range show the same changes, dependent upon aging time. This indicates that the species formed in the films at temperatures above and below the boiling point of water are the same, and that the moisture content of the films may affect the reaction rate, but not the mechanisms. The observed data in the visible region fit the standard pseudofirst-order kinetics model and are in excellent agreement with those determined for both the color change of cotton and the UV absorbance of Cellophane under similar conditions.

In Part I of a four-part series, the author reviews the literature on the aging of cellulose, notes the reasons why an alkaline rinse should be effective in retarding the aging of cellulosic textiles, and presents preliminary results which indicate that treating new cotton and rayon doth with a dilute calcium hydroxide solution can increase their resistance to accelerated aging.In Part II the results of a more detailed study of the effect of a calcium hydroxide rinse on the strength retention and color change of new cellulosic fabrics are reported. It is shown that the treatment is successful in retarding strength loss, but that it has no effect upon color change.

In Part I of a four-part series, the author reviews the literature on the aging of cellulose, notes the reasons why an alkaline rinse should be effective in retarding the aging of cellulosic textiles, and presents preliminary results which indicate that treating new cotton and rayon cloth with a dilute calcium hydroxide solution can increase their resistance to accelerated aging. In Part II the results of a more detailed study of the effect of a calcium hydroxide rinse on the strength retention and color change of new cellulosic fabrics are reported. It is shown that the treatment is successful in retarding strength loss, but that it has no effect upon color change. PART I: PRELIMINARY RESULTS

This study applied economic analysis to an evaluation of the Occupational Safety and Health Administration's standard. The costs and benefits attributable to the standard were identified, measured, and compared. A period of twenty years was used to estimate the costs of the standard to allow for the cumulative effect of cotton dust controls. For a similar reason, benefits were estimated for a forty-year period, since spillover benefits would continue after the expiration of the standard. Various degrees of standard effectiveness were used in view of existing uncertainty about the impact of the standard on byssinosis. The results of the study indicate that benefits are considerably lower than costs throughout the forty-year period. Even under the most optimistic assumptions, costs exceeded benefits by more than two and a half to one. In part, this result reflects the magnitude of costs incurred in the early years of the standard and the delay in accrual of benefits.

The kinetics of the disappearance of propagating butadiene radicals produced in the grafting of butadiene to poly(vinyl chloride) was followed by electron spin resonance measurements. The radical species observed in the temperature range 213-298/sup 0/K is the conjugated allylic radical: --CH/sub 2/--CH==CH--CH/sub 2/ reversible --CH/sub 2/--CH--CH==CH/sub 2/. The reaction conditions were adjusted to provide a highly viscous medium in which the propagation reaction took place. Under these conditions the radicals were stabilized and a precise ESR spectrum was obtained. Arrhenius plots of the second-order decay rate constants yield an activation energy of 5 kcal/mole. This suggests that the bimolecular termination reaction is controlled by the segmental motion of the grafted side chains.

The radiation-induced grafting of butadiene (BD) from methanol solution to films of low density polyethylene (LDPE), chlorinated polyethylene (PECL), and poly (vinyl chloride) (PVC) was studied as a function of chlorine content, dose rate, irradiation time, and BD concentration at room temperature. It was found that the graft yield to PECL increased with increasing glass transition temperature (Tg) of the polymer until the Tg of the chlorinated polymer was equal to the reaction temperature. As the degree of chlorination was increased beyond this point, little increase in graft yield was realized. Further increase in graft yield was obtained upon dilution of the monomer with methanol. The results are explained in terms of the effect of the added chlorine and absorbed monomer on the viscosity of the monomer-swollen amorphous polymer.