Ester ethoxylates biodegradation

The second class includes polyethylene glycol alkyl esters, ethoxylated linear aliphatic alcohols, ethoxylated natural fatty acids and oils, and alkanolamides. These products, together with ethylene oxide block copolymers with propylene oxide, form a class of ethoxylate surfactants that are biodegradable. Linear alcohol ethoxylates find extensive use in heavy-duty laundry detergents. 

Linear Secondary Alcohol Ethoxylates (LSAE). The hydrophobes of LSAE are made via borate-modified oxidation of n-parafiins to form inorganic esters followed by hydrolysis. The resulting alcohols contain secondary hydroxyl groups randomly located along the linear alkyl chain. LSAE biodegrade slightly slower than LPAE (13.14). 

The three transitions mentioned above, replacement of branched alkylben-zene sulfonates by linear alkylbenzene sulfonates, replacement of alkylphenol ethoxylates by alcohol ethoxylates and substitution of ester quats for stable quats are all driven by environmental concerns. Rate of biodegradation and aquatic toxicity are the major parameters taken into account, and, in order to pass the regulations that the European Union has adopted, a surfactant must pass the criteria of showing ... 

It is common practice to put the experimentally obtained values for biodegradation and aquatic toxicity into a kind of matrix, as is illustrated by Fig. 2. The shaded areas in the matrix are the approved areas . Out of the six product types discussed above linear alkylbenzene sulfonates, alcohol ethoxylates, and ester quats lie within the shaded areas, while branched alkylbenzene sulfonates, alkylphenol ethoxylates and stable quats do not. 

Ortho ester linkages can also be used to improve biodegradation properties in long chain ethoxylates or block copolymers. It has been shown that a conventional PEG-PPG copolymer with a molecular weight of 2200 biodegrades to only 3% in 28 days. However, if an equivalent molecule is built up from PEG 350 and PPG 400, connected by ortho ester links, it will reach 62% biodegradation within 28 days and thus be classified as readily biodegradable [64]. 

Linear primary alcohols and alpha olefins in the C6-C 8 range have enjoyed remarkable growth in the last three decades. As esters, the C6—C,0 alcohols are used for plasticizing PVC. In the C 2-C]g range, the alcohols are used to make readily biodegradable surfactants of various types such as ethoxylates (nonionic), alcohol sulfates, and sulfates of ethoxylates (anionic). Alpha olefins are used as polyethylene comonomer (33%) and as raw materials for detergent alcohols (22%), oxo alcohols (10%), and lubricants and lube oil additives (18%). 

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