amphiphiles in oil/water, supercriticalcarbon dioxide/water andhalocarbon/water phases, as well asaqueous systems, has been studied,highlighting the critical role ofsurfactant chemical structure inoptimizing the stability of novelinterfaces. Many real-life formulationscontain mixtures of surfactants withpolymers, and the interactionbetween the two can significantlymodify the behaviour of the individualcomponents in solution and atinterfaces, sometimes beneficially,sometimes deleteriously. PeterGriffiths of Cardiff University outlinedthe range of techniques employed tocharacterize and understand theseimportant interactions.

Randall Hill of Dow Corning (USA)discussed the role of surfactants inwetting and spreading and, inparticular, the behaviour of sometrisiloxane polyoxyethyleneoxidesurfactants that manifest the unusualphenomenon of ‘superwetting’.Recent work has revealed theexistence of a critical wettingconcentration well above the CMC.The superwetters were used toillustrate various time-dependent andspatial variation effects on wettingbehaviour. Finally, Peter Dowding ofInfineum UK Ltd considered thestabilization of colloidal suspensionsand how the structure of thestabilizing surfactant affects theresultant stability and solubilizationcapacity of the dispersion.Surfactants adopt an optimalcurvature in the formation of astabilized suspension; recent workhas shown that amphiphilic moleculescalled ‘linkers’, which segregate neareither the head- or the tail-group ofthe surfactant, can modify thiscurvature in a similar way to co-surfactants. The structure, andtherefore properties, of the surfactantlayer can also be modified bychemically linking head-groups toform dimeric Gemini-type surfactantsor even polymeric surfactants.Moreover, if the colloidal media isbeing used as a site for organic orinorganic reactions, then introducingfunctionality into the surfactant in thisway can also tailor the properties ofthe reaction products within thecolloid.

Caroline Edser

RAWMATERIALS

Linear alkylbenzene

Gulf Petroproducts in LAB feedstocktalks

Gulf Petroproducts is involved in talkswith gas-to-liquids (GTL) players inQatar for feedstock supplies for itslinear alkylbenzene (LAB) project inYanbu, Saudi Arabia. The company ishoping to source n-paraffin from GTLplants rather than building its own n-paraffin plant. It had been negotiatingwith Saudi Aramco for the supply ofkerosene, a feedstock for producingn-paraffin, but it does not consider thekerosene price competitive comparedwith building a LAB plant that uses n-paraffin from GTL plants. Gulf Petro-products will first build an 80,000tonnes/y LAB plant using n-paraffinfrom GTL plants and will only proceedwith its own n-paraffin unit at a laterdate. Talks with Saudi Aramco aboutthe supply of kerosene are ongoing.The $125-130 M LAB project isscheduled to start up in 2Q 2006.

Asian Chemical News, 31 May 2004, 10 (447), 19

Alpha-olefins

Alpha-olefins – a question of balance

Linear alpha-olefin (LAO) productiontechnologies can generate productswith an even number of carbonatoms, from C4 (butene-1) to C30+(triacontene). The LAOs producedhave applications in various sectors,and include polyethylenecomonomers (C4-C8); syntheticlubricants (C10); detergents (C12-C14); oilfield chemicals and paper-sizing agents (C16-C18); lubricantadditives (C20+) and wax rheologicalmodifiers (C24+). A potential formarket imbalance is becomingapparent as PE comonomer growth isoutpacing that of higher fractions.New process technologies are beingdeveloped for the production of justthe lower fractions. They includeSabic/Linde’s Alpha-Sablin process,which should be commercialized inthe medium term, Axens’ Alphaselectand UOP’s Linear-1. New butene-1production facilities are being opened

in Antwerp, Belgium, by Degussa(Oxeno) and in Al Jubail, SaudiArabia, by Petrokemya. Reference ismade to the various LAO processesbeing utilized by the main producers.

European Chemical News, 31 May 2004, 80 (2102),16-18

LAO demand still flat

Global operating rates for linearalpha-olefins have declined over thepast 2 years by 5 percentage pointsto around 75%. Demand for LAOs in2003 remained flat. Demand from thedetergent sector declined during 2003,due to substitution from cheaperalternatives. No new capacity is beingconsidered in the near future.

Oils and Fats International, May 2004, 20 (3), 10

Oleochemicals

New fatty acid plants

A 350 tonnes/d fatty acid plant is tobe built by Palm-Oleo Sdn Bhd ofMalaysia in Zhangjiangang,Shanghai, China. It will producefractionated fatty acids, glycerine andsoap chips. The plant will increasePalm-Oleo’s splitting capacity to over1000 tonnes/d. NatOleo is building a700 tonnes/d fatty acids plant in PasirGudang, Malaysia. CMB is to providefat splitting units at both plants, whichare each expected to begincommercial production in 2H 2005.

Oils and Fats International, May 2004, 20 (3), 11

MDEX Annual Palm and Lauric OilsConference

The main issues raised at the MDEXAnnual Palm and Lauric OilsConference during Mar 2004 includedglobal production and consumption,and the use of discriminatory importduties. Global vegetable oilproduction is expected to rise byaround 5 M tonnes this year withconsumption predicted to increase by4 M tonnes; however, productiongrowth is very dependent on weather.Production of oil in India is expectedto fall from 6.890 M tonnes in 2003-2004 to 5.85 M tonnes in 2004-2005.The country’s per capita consumptionwill total 10.92 kg in the current year.Oil imports by India are predicted todecline by 600,000 tonnes to 4.8 M

2 JULY 2004

F O C U S O N S U R F A C T A N T S