As a design of biodegradable water-soluble polymer, high molecular weight polycarboxylates containing biodegradable segments were prepared and their biodegradability and builder performance in detergent formulations were evaluated. Both natural polysaccharide derived from polycarboxylates containing unreacted sugar residues and chemically synthesized polycarboxylates containing poly (vinyl alcohol) blocks as a biodegradable segment showed similar tendencies. That is, the biodegradability and builder performance of the polycarboxylates varied inversely with the biodegradable segment content. However, the builder performance was improved when more a polymeric carboxylate was used in the detergent process. The minimum required structure needed as a biodegradable segment in the polymer chain with respect to the configuration and block length were clarified using the specific microbes and enzyme. High molecular weight polycarboxylates containing ester, ether and carbonyl groups were also evaluated and compared for biodegradability and builder performance. Biodegradability and builder performance were correlated with the molecular weight in order to develop biodegradable functional polymers by the reduction of their molecular weight to the extent that the environmental microbes can assimilate them.
The influence of sodium polyacrylate (Na-PAA) on the deposition of dispersed polystyrene (PS) latex particles on cotton and nylon-6 fibers in water was studied from the standpoint of interaction energy between latex particles and fibers. The deposited amount and rate of deposition of PS latex particles on the fibers in the presence of Na-PAA were less than when Na-PAA was absent, particularly in the case of cotton fibers. This inhibitive action of Na-PAA on the deposition of PS latex particles on both fibers was slightly more effective in the case of Na-PAA with high molecular weight than with low molecular weight. The above-mentioned function of Na-PAA on cotton fibers may possibly be due primarily to steric repulsive interactions, since total interaction energy (VT) due to electrostatic and van der Waals' forces between latex particles and fibers did not increase by the addition of Na-PAA. And the function of Na-PAA on nylon-6 fibers may be due primarily to steric repulsive interactions similar to those noted cotton fibers, although the contribution of electrostatic repulsive interactions must be taken into consideration.
Interactions between L-α-phosphatidylglycerol sodium salts and water molecules were examined primarily with a differential scanning calorimeter (DSC) and surface pressure meter. With an increase in alkyl chain length of L-α-phosphatidylglycerol sodium salts, stability of the coagel phase relative to that of the gel phase increased due to decrease in the dissociation of counterions (sodium ions). Monolayers of L-α-phosphatidylglycerol sodium salts (PG-Na) were readily converted to expanded monolayers with NaCl, and the temperature at which only expanded monolayers formed was in good agreement with a gel-lamella crystalline transition temperature (Tc). The molecular orientation of the PG-Na monolayer was shown in some causes to differ with that of its bilayer.
Keratin was hydrolyzated by calcium hydroxide to obtain hydrolysis products. The foaming components constituted a fractionated portion of keratin hydrolysate by membrane ultrafiltration. Foam height and stability of the fraction were related to the moleculer weight of each fraction. Fractions with molecular weights (FMW) range from 5, 000 to 10, 000 had the highest foam heights and the greatest foam stability. Those with FMW below 5, 000 had the lowest foam height and least foam stability. Fractions with FMW above 10, 000 differed somewhat from each other in foam height and foam stability.
A simple and rapid spectrophotometric method was developed for the determination of sodium dodecyl sulfate (SDS). The method was based on formation of the SDS- [Copper (II) -1, 10-phenanthroline] ion pair and extraction into isobutyl methyl ketone (MIBK). The ion pair in MIBK was reduced with 1-butanethiol to form an intensely colored copper (I) complex. By this method, the overall concentration of SDS can be determined indirectly from the absorbance of copper (I) complex formed in MIBK. The calibration curve was linear over the range of the detection limit from 8.3 × 10-7 to 6.3 × 10-5 M of SDS. The relative standard deviation of nine successive determinations was 1.02 % at 2.5 × 10-5 M of SDS. The sensitivity of the proposed method is comparable to that of the indirect atomic absorption method for SDS which is accepted as a highly sensitive method.
Lipids of seven edible pulses in Nepal were examined. Total lipid content range was determined as 1.814.7 %. Major components of total lipids were triacylglycerols, constituting 7576 % of total lipids of soybeans and chick pea. The amounts of phospholipids present in grams ranged from 4447 %. Pigeon pea and yellow gram contained greater amounts of free fatty acids compared with the other species of pulses. Fatty acid compositions of soybean and chick pea were virtually the same, in contrast pigeon pea which contained less C18 : 1 and more C16 : 0. Black gram contained the most C18 : 3, over 50 % of the total. The lipids of pigeon pea and grams containing large amounts of free fatty acids showed very high TBAV and COV. It follows from the present results that pluses, split and without seed coat, may possibly undergo oxidation more rapidly.