Preparations and Surface Activities of Alkyl lactates, Alkyl

• Main Authors: Youk-Meng Choong, 鍾玉明
• Other Authors: Min-Hsiung Lee
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/88843853990227684026

博士 === 國立臺灣大學 === 農業化學系 === 84 === The surfactant is a very useful category in industry. It is a of economically valuable additive. In this research, we try to develop the new surfactants by reacting the lipophilic long chain fatty alcohols (C8~C18) with the hydrophilic organic acids such lactic, malic, tartaric and citric acids to synthesize the acid fatty alcohol esters, and to evaluate their surfactant activities. From this study, we found that the organic acid fatty alcohol esters could be effectively synthesized in the presence of concentrated sulfuric acid by heating at 100-140 ℃. The esterification rates were up to 80-95%, and the yields were up to 75-90%. Four series of organic acid fatty alcohol esters were synthesized in this study. They included alkyl lactates (ALs), alkyl malates (AMs), alkyl tartarates (ATs) and alkyl citrates (ACs). The four series of synthesized products were all ester mixtures containing mono-ester, di-ester and/or tri- ester. The synthesized esters an appropriate fatty alcohol chain length indicated excellent surface activities. They showed good surface tension lowering activities, good emulsifying activities, large emulsion capacity, high buffer capacities, low foaming properties, excellent wettability and rewettability, good dispersing power, good detergency and excellent anti-rust activities. Among the current newly developed surfactants, alkyl lactates (ALs) was the non-ionic surfactant; while alkyl malates (AMs), alkyl tartarates (ATs) and alkyl citrates (ACs) were the the mixtures of anionic and non-ionic surfactants. They all showed low skin irritation and very low toxicity ( LD50 > 5g/Kg body weight).These novel surfactants were biodegradable and were very friendly to the enviroment. The LC 50 for fish were all greater than 50 ppm.