Papers by Keyword: Preservatives

Abstract: This research aims to study the antimicrobial activities of five selected plants, which were cinnamon bark, betel leaves, licorice, ginger, and galangal and select the most effective herbal extracts to be evaluated for their preservative efficacies in aqueous gel formulation. The sequential solvent extraction using hexane and 95% ethanol was used to extract bioactive constituents in the studied plants. After completely evaporated the solvents, the crude extracts were tested for the antimicrobial activities against S.aureus TISTR 1466 (ATCC 6538), P.aeruginosa TISTR 781 (ATCC 9027), E.coli ATCC 7839, C.albicans TISTR 5779 (ATCC 10201) and A.brasiliensis DMST 15538 (ATCC 16404) by agar well diffusion method. The result showed that the cinnamon bark extract macerated in hexane could inhibit the growth of all studied micro-organisms and was more effective than betel leaves, ginger, galangal and licorice extracts, while its 95% ethanolic extracts obviously showed lower antimicrobial activities. The MIC and MBC or MFC of cinnamon bark extract against the testing micro-organisms were in a range of 0.039-0.312 mg/mL and 0.156-1.250 mg/mL/0.078-0.625 mg/mL, respectively. The effective doses of hexane extract of cinnamon bark attempted to be tested as preservative in aqueous gel formulation were 0.3%, 1.25% and 2.5% by weight, which were equal to MIC, 4MIC and 8MIC, respectively. The challenge tests according to ISO 11930 were carried out to determine the preservative efficacy. The results revealed that 1.25% and 2.5% of cinnamon bark extract satisfied the criteria B for bacterial strains and the criteria A for yeast and mold. The LC-MS data confirmed that the two main constituents in hexane extract of cinnamon bark were coumarin and cinnamaldehyde that might play a role in antimicrobial activity.

Abstract: Xylan preservative is harmless to humans and animals, contaminate the environment of new wood preservatives.This paper from bagasse, rice husk, corncob, xylan extracted from birch, testing the corrosion resistance of these four preservatives and CCA compared with the results show that: white rot fungus specimen weight loss rates were: Bagasse xylan: 2.41%, rice husk xylan: 2.65%, corn cob xylan: 2.53%, birch xylan: 2.33%, CCA rate of 4.08% weight loss.

Abstract: Xylan preservative is a new type of wood preservatives ,which is not only harmless to humans and animals, but also no contaminates the environment. Through the extraction of corn cob xylan, anti-corrosion performance testing and compared with the CCA, the results shows that: white rot fungus specimen weight loss rates were: 2.53%, and CCA weight loss rates were 4.08%. In this paper, we carried out through cottonwoods of different states to measure, research and analyse the main chemical composition on their moisture content, benzene - alcohol extract content, lignin content and whole fiber content, which is for future improvement preservatives formulated to provide experimental data, through the comparison of chemical composition among different states of cottonwoods to find out how the effects of preservatives on cottonwood anticorrosive were. The experiments indicated that benzene-alcohol extractive contents of anticorrosion cottonwood and fresh cottonwood were close to 4.50% and 4.51%, while decayed cottonwood of benzene-alcohol content of drawn increased to 5.70%. Lignin contents of anticorrosion and fresh cottonwood were close: respectively, 22.10% and 22.55%, from 24.19% rotten cottonwood. The whole fiber content of Anticorrosion cottonwood, fresh cottonwood and decayed cottonwood were, respectively,66.62%, 84.55% and 64.19% .

Abstract: Preservative was very necessary used in coated paper coating. Preservative was typical paper additive which was low dosage and high yield. Preservative classification, function mechanism and application technology of coated paper coating was introduced and summarized by the numbers in this paper. Finally the development direction and prospect of preservative used in coated paper coating was prospected.

Abstract: Concrete is the most consumed building material worldwide today, which durability has been paid close attentions for a long time. Currently，the design lifetime of many buildings is over 100 years. At present, many projects adopt preservatives to extend the durability of concrete. the paper makes contrastive studies on mechanical properties, ASTM flux, RCM chloridion diffusion, Permit in situ chloridion permeability, Autoclam water absorption, and freezing & thawing resistance between preservatives-added and non-preservative concretes at different typical strengths; and concludes correlations between the preservatives at different strengths and the durability of concrete, thus to evaluate the influence of various preservatives on the durability of high-performance concrete.