Rosin Soap Exhibits Virucidal Activity

Chemical methods of virus inactivation are used routinely to prevent viral transmission in both a personal hygiene capacity but also in at-risk environments like hospitals. Several virucidal products exist, including hand soaps, gels and surface disinfectants. Resin acids, which can be derived from Tall oil produced from trees, have been shown to exhibit anti-bacterial activity. However, whether these products or their derivatives have virucidal activity is unknown. Here, we assessed the capacity of Rosin soap to inactivate a panel of pathogenic mammalian viruses in vitro. We show that Rosin soap can inactivate the human enveloped viruses: influenza A virus (IAV), respiratory syncytial virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For IAV, rosin soap could provide a 100,000-fold reduction in infectivity. However, Rosin soap failed to affect the non-enveloped encephalomyocarditis virus (EMCV). The inhibitory effect of Rosin soap against IAV infectivity was dependent on its concentration but not dependent on incubation time nor temperature. Together, we demonstrate a novel chemical inactivation method against enveloped viruses, which could be of use in preventing virus infections in certain settings.

Preparation and characterization of a fly ash and cement-based foam composite

Industrial waste fly ash and ordinary Portland cement (PO42.5) were used as the main raw materials, Ca(OH)2 as the alkali activator, modified rosin soap as the foaming agent, and glass fiber as the reinforcing agent. A physical foaming technology was chosen to fabricate a fly ash and cement-based foam composite. The effects of water-to-binder (W/B) ratio and glass fiber addition on the performance of the foam composite were studied. The structure formation and reinforcement mechanism of the foam composite were discussed, and the optimal formulation was determined, which provides a new technical approach to utilize fly ash and improve the strength and reliability of foam cement products. The results show that different water-to-binder ratios directly affect the stability of the pores during the foaming process, and the glass fiber has a protective effect on the foam. When the W/B ratio is 0.5, meanwhile the addition of glass fiber is 1.5%, the fly ash and cement-based foam composite can achieve better physical performance: the dry density is 368 kg/m3, the water absorption rate is 39.12%, and the 28-day compressive strength is increased by 86.31% (reaching 3.47 MPa) compared to that of the sample without a glass fiber.

Tensile Properties of Films from Low-Temperature GR-S Latex

Studies were made of the influence of a number of polymerization variables on the tensile strength of vulcanized evaporated films from low-temperature high-solids GR-S latexes. Previous reports of film tensiles on the order of 3000 pounds per square inch for latexes of 70/30 butadiene-styrene charge ratio were confirmed. The levels of accelerator necessary for optimum vulcanized properties were found to be considerably lower than those normally used, particularly for latexes shortstopped with dithiocarbamate salts. Microscopic coagulum found in some latex samples had a pronounced effect in decreasing film tensile of vulcanizates. Cured films from latexes emulsified with mixtures of fatty acid and rosin soap possessed considerably better tensile strengths than those from latexes using all fatty acid soap emulsification. Wide variations on Mooney viscosity had relatively little effect on ultimate film tensiles. Incorporation of small amounts of lignin into the latex as the ammonium or sodium salt decreased cure rates of films and aided in giving more reproducible tensile results. Both lignin and the sodium salt of cresyl monosulfide improved the aging characteristics of films.

GR-S Emulsified with Rosin Soap

One of the most troublesome deficiencies of standard GR-S, in so far as product fabrication is concerned, is the inherent lack of tackiness or the incapability of laminated and spliced surfaces to flow and knit together easily. This was especially bothersome from 1942 to 1944, when the scarcity of natural rubber forced fabricators to use a synthetic polymer before they had developed satisfactory methods and equipment to compensate for its deficiencies. Early in 1942, in anticipation of a later scarcity of fats and oils suitable for making the soap used for emulsification, the several groups working on polymer development problems intensified their efforts to find emulsifying agents which could be made from noncritical domestic materials. Rosin was one of these. Early attempts to use it were unsuccessful, however, because the polymerization reaction was strongly retarded. Later the Hercules Powder Company and The B. F. Goodrich Company, working together, found that the retarding effect could be greatly reduced with the use of disproportionated rosin previously referred to as dehydrogenated rosin. (The treatment given to the rosin results in a molecular disproportionation of the hydrogen, with the elimination of the conjugated double bonds accountable for much of the inhibiting effect on the polymerization reaction.) This work made rosin available for use in the event of an actual scarcity of fats and oils of good quality.