Urea adducts prepared from pure fatty acids, their methyl esters and urea dissolved in methanol were used as samples for dissociation temperatures. Dissociation temperatures of the urea adducts were deterz mined by the differential thermal analysis and micro melting point method. The results of the temperatures obtained by two methods were in good agreement.
We developed an improved artificially soiled cloth by introducing a new method, which we called as an aqueous dispersion method. Cotton cloth was dipped in the water in which oily soil, protein (gelatin), carbon black and clay had been dispersed. This clay, called as red-yellow diluvium, is developed on the diluvial upland in the Tokai district and is a typical diluvium in Japan. We chose it among many types of clay in Japan. After impregnating, the soiled cloth was squeezed by beefing passed through rubber-rollers, and then, in order to denaturalize protein, it was heated at 105°C for 30 min. We examined the behavior of soil removal from this artificially soiled cloth comparing with naturally soiled collar cloth and other artificially soiled cloth prepared from Hitachi-Lion dry method and organic solvent method. We found that the new artificially soiled cloth behaved similarly to naturally soiled collar cloth under various washing conditions such as washing temperature, water hardness and polyphosphate dosage, and, furthermore, had an excellent sensitivity for evaluating detergency of some heavy duty powder detergents on the market.
Chelatometry of aluminum for the determination of zeolite in detergents has been investigated. Aluminum ion liberated from zeolite dissolved in dil. nitric acid forms a complex with EDTA at pH 33.5, and can be determined by titrating the excess amount of EDTA with zinc (II) acetate at pH 56 using xylenol orange as an indicator. It is well known that Al-EDTA complex is selectively dissociated into each species by boiling in the presence of fluoride ion. This fact suggests that aluminum ion can be determined without interferences from other contaminated heavy metals. Therefore, aforementioned test solution under the end point is treated with fluoride ion, and then liberated EDTA equivalent to aluminum is determined by titrating in the same manner. Sodium citrate, sodium malate, and sodium tartrate give no interferences to the determination of zeolite, however the presence of STPP, NTA and EDTA affords low recovery of zeolite. Interference by STPP can be completely eliminated by its hydrolysis in nitric acid. In order to exclude the interference from EDTA, the present method is modified for the simultaneous determination of zeolite and EDTA. The results of determination of EDTA in the presence of zeolite are in good agreement with those obtained from total nitrogen measurements. Consequently, the present method becomes applicable to the determination of zeolite in commercial detergents with satisfactory accuracy.
Ethylenediaminetetraacetic acid was introduced to glycidyl group attached to acryl ester polymers [ethyl acrylate (EA) : glycidyl methacrylate (GMA) (1 : 1 and 2 : 1), butyl acrylate (BA) : GMA (1 : 1), and GMA homopolymer] to form the polymer containing chelating Ligands as pendant groups. Chelate polymers were obtained by the reaction of the polymers with some transition metal ions. Aqueous solution (0.2%) of Ni-chelate of the polymer derived from EA : GMA (2 : 1) copolymer was found to have 47.6 dyn/cm in surface tension and 11.7dyn/cm in interfacial tension for kerosene. Ni- and Zn- chelates of the polymer derived from BA : GMA (1 : 1) copolymer had excellent emulsifying powers for the mixture of kerosene-water.