Comparative analysis of radical‐mediated polyethylene modifications: Vinyltriethoxysilane versus mercaptopropyltriethoxysilane addition

The efficiency and selectivity of two approaches for introducing alkoxysilane functionality to polyethylene (PE) are examined along with the moisture‐curing performance of the resulting products. Although the peroxide‐initiated grafting of vinyltriethoxysilane to PE is accompanied by undesirable crosslinking, comparable silane contents can be introduced without affecting the melt viscosity through the addition of mercaptopropyltriethoxysilane (MPTES) to the unsaturation within the polymer. Rapid hydrogen atom donation by thiols underlies this unique selectivity for grafting versus molecular weight alteration, and gives rise to a remarkable tolerance of MPTES additions to phenolic antioxidants. Direct comparisons of the moisture‐curing efficiencies provided by the two functionalization techniques reveal few significant differences in crosslink yields or composition distributions. POLYM. ENG. SCI., 46:480–485, 2006. © 2006 Society of Plastics Engineers.     

Shape factor for an underground vertical infinite cylindrical structure

An analysis for steady-state heat transfer between an underground vertical infinite cylindrical structure and ground is presented, and is used as a direct method to evaluate conduction shape factor for the structure. Numerical values of the shape factor have been determined after solving the transcendental equation involved here, subject to some valid approximation, and found to converge to a finite value. The convergence has also been verified by studying the numerical values of the shape factor for different length:radius ratio of the cylindrical structure and the result is convincing.     

Optimum cone angles in aeroelastic flutter

The determination of flutter frequencies and flutter boundary pressures of conical shells is carried out using finite element analysis. Static condensation procedure with Q.R. algorithm is used for the extraction of eigen values of the system. An empirical relation for determining the values of flutter boundary pressures of clamped-clamped conical shells is proposed. It is seen that there is an optimum semivertex angle at which a given conical shell of prescribed length and initial radius offers maximum resistance for flutter.     

Chemical Investigations on Celastrus paniculatus Seed Oil I

Fatty acid compositions of four lipid fractions of Celastrus paniculatus seed namely normal triglycerides (20.2%), polar triglycerides (44.4%), polar nonglyceridic ester (23.5%), and nonpolar nonglyceridic ester (11.9%), have been determined by gas liquid chromatography. Percentage contents of major component acids in these fractions are: palmitic, 25.1, 42.0, 12.7, 58.2; stearic, 6.7, 4.5, 15.8; oleic, 46.1, 24.8, 4.7, 14.2; linoleic, 15.4, 14.7, 10.0; and linolenic, 3.0, 13.1, 43.0, respectively. The major molecular species constituting the normal triglycerides are: palmitooleopalmitin, 6.8%; palmitooleostearin, 5.6%; palmitodiolein, 14.7; palmitooleolinolein, 7.0%; stearodiolein, 6.1%; triolein, 8.0% and dioleolinolein 7.6%. Lipolysis of the polar triglyceride indicated as high as 59.6% of saturated acids linked to the 2-position of glycerol.     

Triglyceride composition of Buchanania lanzan seed oil

The fatty acid composition of Buchanania lanzan seed oil, determined by urea complex formation and gas liquid chromatography (g.l.c), was found to be: myristic, 0.6; palmitic, 33.4; stearic, 6.3; oleic, 53.7; and linoleic, 6.0%. Triglyceride compositions of the native seed oil and its randomised product were calculated from the fatty acid compositions of the triglycerides and of the corresponding 2-monoglycerides produced by pancreatic lipase hydrolysis. The oil is composed of 3.2, 35.8, 45.5 and 15.5% trisaturated, monounsaturated disaturated, diunsaturated monosaturated and triunsaturated glycerides respectively. The special characteristic of the B. lanzan seed oil is its content of 22.7, 31.0 and 11.3% dipalmitoolein, dioleopalmitin and triolein respectively. The percent GS₃ content in the oil increased from 3.2 to 7.5 by the process of randomisation. On directed interesterification the oil yielded a product with a slip point of 41.5°C which may be suitable as a coating material for delayed action tablets. The oil also appears to be a promising one as a commercial source of palmitic and oleic acids.     

Polyol surfactants derived from moringa seed oil for potential use in the pharmaceutical industry

Two polyol surfactants ((a) a crude product of 60% monoglyceride content and (b) a homogeneous sorbitan ester) have been prepared by alcoholysis from the not well known edible Moringa concanensis seed oil. These products constituted mainly oleic acid, which will be suitable for utilisation in the pharmaceutical industry. The optimum conditions of glycerolysis of the moringa seed oil have also been found.     

The component fatty acids of chaulmoogra oil

The fatty acid composition of the seed oils of the species, Hydnocarpus kurzii, H. wightiana and H. odorata were determined by gas-liquid chromatographic (g.l.c.) analysis. The percentages of individual fatty acids were found to be: hydnocarpic 23.0, 33.9, -; chaulmoogric 29.6, 35.0, -; gorlic 25.1, 12.8, -; lower cyclic homologues 0.3, 4.6, -; myristic 0.6, 0.8, 0.4; palmitic 8.4, 5.6, 11.8; stearic -, 0.6, 4.7; palmitoleic 6.0, 1.3, 0.5; oleic 5.4, 3.6, 21.8; linoleic 1.6, 1.8, 29.3; linolenic -, -, 31.2; respectively.     

Nutritional Aspect of Sal Meal

A nutritional study was carried out with white albino rats fed treated and untreated sal meal at 30% level in diet for 3 months. The effect of high protein level in diet on rats fed 30% untreated sal meal was also investigated. rats fed 30% sal meal with intact tannin showed abnormal lipid spectrum and also protein content in both liver and serum while the lipid spectrum and protein content in liver and serum of rats fed 30% treated sal meal were comparable to that of control rats. The toxic effect of sal meal was reduced to some extent when the protein level was improved in diet.