• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.339-340
• /
• 2002

Natural castor oil was chemically reconstructed to extend the carbon chains by means of iso-reaction so as to improve the rheological behavior, by way of increasing the viscosity index and decreasing the pour point. The rheological and tribological characteristics of the reconstructed castor oil were comparatively investigated with those of the natural castor oil and several other vegetable oils and a mineral oil. The friction and wear test results on a four-ball machine indicate that the chemically reconstructed castor oil has considerably improved rheological and tribological properties as compared with the natural castor oil. It shows a greatly increase viscosity index and largely decreased pour point, which makes it applicable to low temperature lubrication. The chemically reconstructed castor oil even shows better tribological behavior than pentaerythritol ester or di-iso-capryl sebacate. However, it is still needed to increase the oxidation stability of the reconstructed castor oil.

• Journal of Adhesion and Interface
• /
• v.18 no.4
• /
• pp.179-182
• /
• 2017

Waterborne polyurethanes(WPU) based on castor oil were successfully prepared using polycaprolactone diol(PCL), castor oil(CO) and 4,4'-methylene dicyclohexyl diisocyanate($H_{12}MDI$) as soft segment part, dimethylolbutanoic acid (DMBA) as emulsifier, and trimethylamine(TEA) as neutralizer based on different molecular weight of prepolymer. The various properties such as mechanical strength and surface reforming were evaluated using UTM, contact angle, FE-SEM based on the different molecular weight of polyol. Waterborne polyurethanes based on castor oil could be considered as a promising candidate to be applied the various adhesion fields.

• BMB Reports
• /
• v.47 no.2
• /
• pp.92-97
• /
• 2014

We have examined the effect of bithorax complex genes on the expression of castor gene. During the embryonic stages 12-15, both Ultrabithorax and abdominal-A regulated the castor gene expression negatively, whereas Abdominal-B showed a positive correlation with the castor gene expression according to real-time PCR. To investigate whether ABD-B protein directly interacts with the castor gene, electrophoretic mobility shift assays were performed using the recombinant ABD-B homeodomain and oligonucleotides, which are located within the region 10 kb upstream of the castor gene. The results show that ABD-B protein directly binds to the castor gene specifically. ABD-B binds more strongly to oligonucleotides containing two 5'-TTAT-3' canonical core motifs than the probe containing the 5'-TTAC-3' motif. In addition, the sequences flanking the core motif are also involved in the protein-DNA interaction. The results demonstrate the importance of HD for direct binding to target sequences to regulate the expression level of the target genes.

• KSBB Journal
• /
• v.14 no.6
• /
• pp.696-701
• /
• 1999

The enzymatic hydrolysis of Castor oil for the mass production of ricinoleic acid was studied to find out the optimum conditions such as solvents and the weight ratio of substrate to enzyme. Three different lipases were tested for the hydrolysis of castor oil: lipase from Porcine Pancrease(lipsase PP), lipase from Candida cylindracea(lipase CC), lipase from Candida Rugosa(lipase CR). The poor mass transfer in water caused a low degree of hydrolysis of castor oil. To overcome this problem, organic solvents were used. Among organic solvents tested, hydrophobic solvents gave better results of hydrolysis than hydrophilic solvents. Organic solvents also lowered or changed the effect of pH. Isopropyl ether made complete hydrolysis of castor oil. The ratio of water to isopropyl ether and the ratio of weight ratio of lipase to castor oil were important for the hydrolysis of castor oil. At 30$^{\circ}C$ castor oil was completely hydrolyzed by 4 wt% of lipase in the mixture of isopropyl ether and water(1:1 in volume).

• Journal of Pharmacopuncture
• /
• v.25 no.2
• /
• pp.71-78
• /
• 2022

Objectives: Post-term pregnancy is a condition associated with increased maternal and fetal complications. Administration of castor oil causes cervical stimulation by increasing the production of prostaglandins. We examined the effects of castor oil on cervical ripening and labor induction through a systematic review and meta-analysis. Methods: The search process was performed to obtain relevant articles from databases including Pubmed, Cochrane library, Scopus, Science direct, SID, Iran Medex, and Google Scholar using the English keywords of cervical ripening, post-term, castor oil, labor induction, Bishop score, and pregnancy considering all possible combinations without time constraints and their Persian equivalents from national databases. Results: A total of eight related articles from the 19 primary studies were extracted and systematically reviewed. According to a cumulative chart, the difference in the post-intervention Bishop score was statistically significant (standard mean difference [SMD]: 1.64, 95% confidence interval [CI]: 1.67-2.11, p = 0.001), indicating an effect of castor oil on increasing the Bishop score. In addition, the difference in labor induction was statistically significant after the intervention (odds ratio: 11.67, 95% CI: 3.34-40.81, p = 0.001), indicating an effect of castor oil on increasing the odds ratio of labor induction (experience of vaginal delivery). Conclusion: This meta-analysis showed that oral administration of castor oil is effective for cervical ripening and labor induction. Midwives should closely monitor pregnant women with prolonged labor and collaborate with obstetricians to employ castor oil as a safe intervention to induce cervical ripening and labor to prevent undue caesarean surgery.

• The Plant Pathology Journal
• /
• v.17 no.6
• /
• pp.357-360
• /
• 2001

Gray mold was observed on leaves of castor bean grown in Woniu and Okcheon in Korea in October 2000. Symptoms developed in the form of spot and blight with sporulation of the causal fungi at the marginal or central parts of the leaves. A total of 25 isolates were obtained from the infected leaves of castor bean. Out of the 25 isolates, 5 isolates which originated from Woniu were identified as Botrytis cinerea, while 20 isolates from Okcheon were identified as Amphobotrys ricini based on morphological and cultural characteristics. Two isolates each of B. cinerea and A. ricini were tested for their pathogenicity to castor bean plants. Gray mold symptoms similar to those observed in the fields were induced on leaves of castor bean by artificial inoculation. This is the first report of gray mold in castor bean caused by B. cinerea and A. ricini in Korea.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.10 no.1
• /
• pp.42-48
• /
• 1984

The comparative detergency of Sodium dodecyl sulfate (SDS) solution near the first critical micelle concentration (CMC) was measured by means of a 131 I-labelled castor oil as a soil. More than 95% radiochemical purity of 131 I-labelled castor oil was obtained using potassium lidide as a carrier. Polyester test fabric was soiled with 131 I-labelled castor oil, and washed in a conventional washing apparatus mounted on appropriate devices. Fabric radioactivities were measured before and after washing by a scintilation counter. Near the first CMC, the detergency of SDS was increased with decreasing of surface tension of SDS. It was also shown that 131 I-labelled castor oil was useful for studying the detergency of SDS.

• Korean Journal of Chemical Engineering
• /
• v.35 no.11
• /
• pp.2296-2302
• /
• 2018

Internally plasticized PVC was prepared via chemical reaction of azide PVC and alkynyl group containing castor oil methyl ester. The chemical structure of alkynyl group containing castor oil methyl ester and internally plasticized PVC was characterized with FT-IR and $^1H$ NMR. Properties of internally plasticized PVC, including thermal stability, tensile tests and resistance to extraction in different solvents, was investigated. The results showed that alkynyl group containing castor oil methyl ester, as internal plasticizer of PVC, not only decreased the $T_g$ of PVC from $84.6^{\circ}C$ to $41.6^{\circ}C$ efficiently, but also presented no plasticizer loss in five different solvents. The tensile tests showed that elongation at break and tensile strength of internally plasticized PVC was 353.8% and 18.1 MPa. The internally plasticized PVC has potential application in replacing the traditional PVC material in PVC products with high durability.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.12 no.4
• /
• pp.232-238
• /
• 1992

To understand the basic information on the management and utilization of reed canarygrass (Phalaris arundinacea L.), four cultivars of Palaton. Venture, Castor and Frontier (control) were compared for growth characteristics, dry matter (DM) yield and nutritive value, 1990 to 1992. The reed canarygrass was harvested four times annually, at soiling stage. The average plant height at harvest was 60 cm in Frontier, 57 cm in Palaton and Venture, and 52 cm in Castor. Initial heading and heading date in 1990 were ca. 21 May and 29 May, respectively, regardless of cultivar. The highest yield (12.495 kg/ha) in 1990 was observed by Frontier. In 1991. Palaton. Venture and Frontier outyielded Castor significantly, and the yields of all cultivars in 1992 were not significant, ranged from 11,460 kg (Castor) to 12,298 kg/ha (Palaton). On an average for three years, Palaton (10,592 kg), Venturc (10,405 kg) and Frontier (1 1,277 kg/ha) produced more forages than Castor. In Frontier the percentage of DM distribution at first harvest (spring) was highest (32.4%). However, the distributions at third (summer) and fourth (autumn) harvest were high in Palaton and Venture, compared with Frontier. The nutritive value of reed canarygrass was not significantly different among cultivars, and the percentage of weeds was slightly high in Castor reed canarygrass.

• Clean Technology
• /
• v.17 no.3
• /
• pp.238-243
• /
• 2011

We investigate new polyols based on castor oil for polyurethane. In order to introduce primary alcohol groups, which exhibit higher reactivity with isocyanate than secondary alcohol groups, the secondary alcohol groups on castor oil were modified with maleic anhydride and aminoalcohol derivatives ($H_2N$-R-OH). The reactions with various molar ratio of castor oil and maleic anhydride were done at relatively low reaction temperature in the absence of catalyst. The polyols based on castor oil with flexible side-chains exhibit better miscibility with conventional synthetic polyols.