Natural Oil (natural + oil)

Distribution by Scientific Domains


Selected Abstracts


Application of Modified Natural Oils as Reactive Diluents for Epoxy Resins

MACROMOLECULAR SYMPOSIA, Issue 1 2006
Piotr Czub
Abstract Bisphenol A based low-molecular-weight epoxy resin was modified with epoxidized soybean oil, which exhibit viscosity reducing ability comparable to commercial grade active diluents. The studied compositions showed a non-Newtonian rheological behavior, typical for Bingham liquids. The values of the flow index (n) and the consistency index (k) for the compositions tested in the temperature range 25,65,°C were calculated from the Ostwald-de Waele rheological model and were used to calculate the flow-activation energy (Ea) using the Arhenius equation. Studies of co-crosslinking of mixed oil-resin compositions using isophorone diamine showed essential decrease of the reaction heat and peak maximum temperature. Mechanical properties, thermal stability, water absorption and chemical resistance of the epoxy resin modified with natural oil, were also investigated. Compositions of epoxy resin Ruetapox 0162, modified with the oil diluent, preserved very good mechanical properties of the epoxy resins and demonstrated relatively low water absorption as well as high chemical resistance. The compositions displayed even higher impact strength than pure epoxy resin due to plasticizing effect of the built-in oil. Compositions with the high contents (up to 60 weight %) of the oil were flexible materials with fast elastic recovery. [source]


Impact of topical oils on the skin barrier: possible implications for neonatal health in developing countries

ACTA PAEDIATRICA, Issue 5 2002
GL Darmstadt
Topical therapy to enhance skin barrier function may be a simple, low-cost, effective strategy to improve outcome of preterm infants with a developmentally compromised epidermal barrier, as lipid constituents of topical products may act as a mechanical barrier and augment synthesis of barrier lipids. Natural oils are applied topically as part of a traditional oil massage to neonates in many developing countries. We sought to identify inexpensive, safe, vegetable oils available in developing countries that improved epidermal barrier function. The impact of oils on mouse epidermal barrier function (rate of transepidermal water loss over time following acute barrier disruption by tape-stripping) and ultrastructure was determined. A single application of sunflower seed oil significantly accelerated skin barrier recovery within 1 h; the effect was sustained 5 h after application. In contrast, the other vegetable oils tested (mustard, olive and soybean oils) all significantly delayed recovery of barrier function compared with control- or Aquaphor-treated skin. Twice-daily applications of mustard oil for 7 d resulted in sustained delay of barrier recovery. Moreover, adverse ultrastructural changes were seen under transmission electron microscopy in keratin intermediate filament, mitochondrial, nuclear, and nuclear envelope structure following a single application of mustard oil. Conclusion: Our data suggest that topical application of linoleate-enriched oil such as sunflower seed oil might enhance skin barrier function and improve outcome in neonates with compromised barrier function. Mustard oil, used routinely in newborn care throughout South Asia, has toxic effects on the epidermal barrier that warrant further investigation. [source]


Hybrid Miniemulsion Polymerization of Acrylate/Oil and Acrylate/Fatty Acid Systems

MACROMOLECULAR REACTION ENGINEERING, Issue 3 2008
Juchen Guo
Abstract Acrylate,alkyd hybrid latex via miniemulsion polymerizations show promise as water-borne coating systems. However, poor homogeneity of the particles caused by the immiscibility of the alkyd in polyacrylate limits monomer conversion and film formation. To resolve this problem, the hybrid miniemulsion polymerization of acrylate in the presence of linoleic acid and sunflower seed oil was carried out. Products were characterized by solvent extraction, dynamic light scattering, gel permeation chromatography (GPC), differential scanning calorimeter (DSC), and transmission electron microscopy (TEM). The results provide clear evidence that substituting a fatty acid or natural oil with smaller molecular size (weight) for a conventional alkyd improves the grafting efficiency, and enhances the homogeneity of the hybrid polymer particles in water-borne latex systems. [source]


Application of Modified Natural Oils as Reactive Diluents for Epoxy Resins

MACROMOLECULAR SYMPOSIA, Issue 1 2006
Piotr Czub
Abstract Bisphenol A based low-molecular-weight epoxy resin was modified with epoxidized soybean oil, which exhibit viscosity reducing ability comparable to commercial grade active diluents. The studied compositions showed a non-Newtonian rheological behavior, typical for Bingham liquids. The values of the flow index (n) and the consistency index (k) for the compositions tested in the temperature range 25,65,°C were calculated from the Ostwald-de Waele rheological model and were used to calculate the flow-activation energy (Ea) using the Arhenius equation. Studies of co-crosslinking of mixed oil-resin compositions using isophorone diamine showed essential decrease of the reaction heat and peak maximum temperature. Mechanical properties, thermal stability, water absorption and chemical resistance of the epoxy resin modified with natural oil, were also investigated. Compositions of epoxy resin Ruetapox 0162, modified with the oil diluent, preserved very good mechanical properties of the epoxy resins and demonstrated relatively low water absorption as well as high chemical resistance. The compositions displayed even higher impact strength than pure epoxy resin due to plasticizing effect of the built-in oil. Compositions with the high contents (up to 60 weight %) of the oil were flexible materials with fast elastic recovery. [source]


Latest news and product developments

PRESCRIBER, Issue 7 2007
Article first published online: 11 JUL 200
Poor asthma control with off-licence prescribing Children who are prescribed off-licence medications are more likely to have poor asthma control, according to an analysis from Dundee (Br J Gen Practice 2007;57:220-2). The review of 17 163 consultations identified 1050 (6.1 per cent) who received a prescription for an unlicensed use (defined as not licensed for children or the particular age group, or dose not licensed). High doses (4.5 per cent) were more frequent than unlicensed indications (1.9 per cent). Children who received off-label prescriptions reported statistically significantly more symptoms in the day or night, symptoms during activity, and increased use of daily short-acting beta2-agonists. The authors note that off-label prescribing appears to be increasing. Atkins diet most effective over one year? The ultra low-carbohydrate, high-protein Atkins diet achieved greater weight loss than other popular diets in overweight women over one year, say US investigators (J Am Med Assoc 2007;297:969-77). The study compared the Atkins diet with three diets designed as low- or very high-carbohydrate, or based on USA nutritional guidance, in 311 women with body mass index 27-40. After one year, mean weight loss was 4.7kg with the Atkins diet , significantly greater than with the low- carbohydrate diet (1.6kg) but not compared with very high-carbohydrate (2.2kg) or the nutrition-based diet (2.6kg). Metabolic endpoints were comparable or more favourable in women using the Atkins diet. Androgen therapy linked to gum disease The majority of men treated with androgen deprivation therapy for prostate cancer are more likely to have periodontal disease (J Urol 2007;177:921-4). After controlling for risk factors, the prevalence of periodontal disease was 80.5 per cent among treated men compared with 3.7 per cent in matched controls not receiving treatment. There was no difference in bone mineral density between the groups but plaque scores were significantly higher among treated men. Food Commission rebuts MHRA on additives An independent watchdog has not accepted the MHRA's justification for including certain additives in medicines for children. The Food Commission (www.foodcomm.org.uk) found that most medicines for children contained additives, some of which , including azo dyes and benzoates , are not permitted in food. The Commission called on the pharmaceutical industry to stop using ,questionable additives'. The MHRA stated that the licensing process takes into account the likely exposure to excipients that are considered essential to make medicines palatable to children. Colouring helps children to identify the correct medicine, and preservatives ensure a reasonable shelf-life. A list of additives is included in the product's summary of product characteristics and patient information leaflet. In response, the Commission states: , , it is quite possible to flavour medicines with natural oils or extracts, and natural colourings such as beetroot and beta-carotene can be used instead of azo dyes. If parents were advised to give these medicinal products at mealtimes the manufacturers could also add a little sugar to sweeten their products, rather than relying on artificial sweeteners.' All triptans the same? There is no economic case for choosing one triptan over another and no evidence for preferring a particular triptan for adults, a systematic review has concluded. The Canadian Agency for Drugs and Technologies in Health (www.cadth.ca) found that published trials had compared most triptans with sumatriptan but not with one another, and most economic evaluations were flawed. New drug for HIV Janssen-Cilag has introduced darunavir (Prezista), a new protease inhibitor for the treatment of HIV infection. Licensed for highly pre- treated patients in whom more than one other pro- tease inhibitor regimen has failed, darunavir must be co-administered with ritonavir (Norvir). A month's treatment at the recommended dose of 600mg twice daily costs £446.70. Variation in liquid captopril for children The NHS uses a wide range of liquid formulations of captopril to treat children with heart failure , with no assurance of their bioequivalence (Arch Dis Child 2007; published online 15 March. doi: 10.1136/adc.2006.109389). Specialists in Leicester surveyed 13 tertiary paediatric cardiac centres and 13 hospitals that referred patients to them. Only three tertiary centres supplied the same liquid for-mulation of captopril as their referring hospitals. Four hospitals supplied tablets for crushing and dissolving in water; the other hospitals and centres used a total of nine different formulations. The authors say the formulations had widely varying shelf-lives, determined empirically in all but one case, and were used interchangeably despite a lack of quality control data to establish their bioequivalence. QOF CVD targets not good enough for GPs Two-thirds of GPs want Quality Outcome Framework (QOF) targets for cardiovascular disease brought into line with those of the Joint British Societies latest guidance (JBS2), according to a survey by doctor.net.uk. The survey of 1000 GPs showed that 88 per cent were aware of the JBS2 guidelines and most were already implementing the targets for lipids, blood pressure and blood glucose in some form; however, only 55 per cent were implementing the JBS2 obesity target and 14 per cent were implementing screening for the over-40s. The JBS2 target for lipids in at-risk patients is <4mmol per litre total cholesterol and <2 mmol per litre LDL-cholesterol, compared with <5 and <3mmol per litre respectively in QOF and the NSF. The survey was commissioned by Merck Sharp & Dohme and Schering- Plough. Fracture warning Following warnings in the US that rosiglitazone (Avandia) is associated with an increased risk of fractures in women, Takeda has advised prescribers that pioglitazone (Actos) carries a similar risk. An analysis of the company's clinical trials database has revealed an excess risk of fractures of bones below the elbow and knee. The incidence was similar to the excess risk associated with rosiglitazone and also confined to women. Scottish approvals The Scottish Medicines Consortium (www.scottish medicines.org.uk) has approved for use within NHS Scotland the sublingual tablet formulation buprenorphine/naloxone (Suboxone) for the treatment of opioid dependence. It has also approved the combined formulation of valsartan and amlodipine (Exforge) and the restricted use of the If inhibitor ivabradine (Procoralan). [source]