T. Suprunchuk

Photooxidation of unsaturated oils: Effects of singlet oxygen quenchers

The photooxidative deterioration of unsaturated food oils by near UV and visible light was found to be retarded by nickel (II) chelates well known to quench singlet oxygen (1O2). The rates of hydroperoxide formation during light exposure were unaffected by efficient peroxy radical scavengers such as hindered phenols. α-Tocopherol (vitamin E) underwent a relatively rapid oxidation itself when exposed to1O2 in oil solutions, despite being able to deactivate1O2 quite efficiently. From a comparison of the rates of scavenging by stabilizers and attack on allyl groups,1O2 initiated deterioration is appreciably more difficult to retard than peroxy radical processes.

A Systematic Study of the Effects of Individual Constructional Components on the Flammability Characteristics of a Carpet

The role played by the indiyidual carpet components in the overall flammability performance of a carpet have been investigated. The equipment employed for the evaluation was the National Research Council of Canadas Carpet Flammability Apparatus, which measures relative values for ease of ignition, flame-spread rate, smoke evolution, and rate of heat release. The results obtained indicated that in the case of a nylon level-loop carpet the use of a conventional latex, a secondary jute backing, and the dyeing and finishing process each contribute to the flammability of the carpet. The method of installation also has a pronounced effect on the flammability behavior. Carpets that are glued to cement-asbestos board are less easy to ignite, burn at a slower rate, and give off less smoke and heat compared to carpets not glued down or mounted with an underpad.

Bicomponent Composites: Preparation from Incompatible Polymers by Corona Treatment

Corona treatment of various substrates in nitrogen was found to markedly improve the adhesion between the substrate and polymeric coatings which were subsequently applied by in situ polymerization of the appropriate monomers. Sub strates included films, fibers, and fabrics of polymers such as polypropylene, polyethylene, polyelhylene terephthalate, polytetrafluoroethylene, and Saran. Condensation polymers employed as coatings included polyamides, polyesters, poly- sulfonamides, and poiyureas. Other polymer coatings were also applied by anionic and cationic polymerization. Com posites prepared after corona treatment of the substrate were shown to have superior interfacial adhesion and abrasion and solvent resistance, compared with composites which had been prepared without corona treatment. Electron micro copy was used to demonstiate the difference between differently treated samples of films and fabrics. The good interfacial adhesion exhibited by coatings on corona-treated films, even after extensive elongation of the composites, indicated the possibility of preparing bicomponent fibers from coated substrates which fibrillate on drawing.

The Fire Properties of Cellulose Insulation

The fire properties of cellulose as they relate to the potential fire hazard of cellulose insulation are examined and methods of reducing these hazards are reviewed. The suitability of various smoulder and flame resistance tests for evaluating the fire properties is also considered. The effect of water and temper ature cycling upon combustion retardant chemical migration and resultant fire properties of the material are discussed.

Interferences in the Wet Chemical Analysis of Combustion Retardants in Cellulose Insulation

A quantitative volumetric analytical technique to evaluate the concentrations of borax and boric acid in combus tion retarded cellulose insulation has been evaluated, and the in terference by aluminum sulphate in the determinations investi gated.