| Summary: | 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.
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