No abstract

Palm-based alpha-sulfonated methyl esters (SME) were successfully produced using a 20 kg/h-capacity pilot plant at the Malaysian Palm Oil Board. This anionic surfactant was used as an active ingredient to formulate powder detergent. The production of palm-based powder detergents (PPD) was carried out at the pilot-plant scale. The performance of powder detergents formulated with SME was found to be excellent. At a total concentration of 0.8 g/L, good detergency of PPD was obtained when only using 12% to 18% SME, compared to the commercial detergent with 27% surface-active agent. The foaming power and wetting characteristics of PPD were also comparable to the values for the commercial detergent. The study has shown that PPD were able to biodegrade faster than the commercial detergent, where the maximum time period to reach the pass level (60%) is within 14 days. The toxicity of the PPD, which ranged from 5.66 to 8.0 mg/L, is similar to the toxicity of the commercial detergent. A detailed description of the SME application technologies in powder detergents and the properties of formulated powder detergents are highlighted in this paper.

Methyl ester sulfonate (MES) is an anionic surfactant derived from palm oil through sulfonation of fatty acid methyl esters. Due to limited ecotoxicological data on MES, this study was initiated to evaluate the ecotoxicological properties of MES and its impact to the environment. The respirometric method (OECD 301F) was used to monitor the biodegradation of various homologues of MES over 28 days. The algae growth inhibition test (OECD 201) was conducted to assess the effects of palm‐based MES towards green algae by exposing exponentially‐growing cultures of Pseudokirchneriella subcapitata (P. subcapitata) to five concentrations of MES with maximum concentrations of 100 mg/L. Results showed all MES samples were readily biodegradable, where the biodegradability of each homologue surpassed 60% within 28 days. It was also observed that the longer the carbon chain length of MES, the solubility and the biodegradability rate decreased. The ecotoxicity of C12 and C14 MES towards P. subcapitata after 72 h of experiment showed no inhibition of algae growth in C12 MES while, the growth of algae decreased as the concentration of C14 MES increases. The EC50 value for C14 MES and C16 MES towards green algae was >100 and >10 mg/L, respectively. It can be concluded that C12 and C14 MES were practically non‐toxic towards P. subcapitata and the toxicity increased with an increase in chain length of the surfactant (EC50 value decreases). Therefore homologues of palm‐based MES are not expected to cause environmental concern due to their biodegradability and low toxicity in the aquatic environment.

Average molecular weights (M n , M w and M p ) are important characteristics of oligomers and polymers, and therefore there is a need to have a precise and reliable determination method. A gel permeation chromatography (GPC) coupled with a single refractive index detector was used to determine the molecular weight distributions of commercial polyether polyols calibrated against a series of polyether polyols with known molecular weights and low polydispersity. Results of these GPC analyses were compared to the ones calibrated against the commercially available polystyrene (PS) standards. The number-average molecular weights (M n ) obtained with GPC using polyether polyols calibration were closer to the theoretical values than the M n obtained using PS as calibration standards. Hence, these GPC analyses using polyether polyols as calibration standards can provide reliable determination of molecular weight distribution of polyether polyols and can be potentially applied to natural oil-based polyols, including palm oil-based polyols.

Natural oil polyols have been intensively developed and successfully used for the production of various polymers, notably polyurethanes. The need to access the average molecular weight (MW) and the MW distribution (MWD) has led to the efforts to have a precise and reliable determination method. A series of commercial polyether polyols, with well‐defined MW, was used as a gel permeation chromatography (GPC) calibration standard to determine the MW of palm olein polyols. This GPC analysis was compared to the one calibrated against the commercially available polystyrene (PS) standards and to the number‐average molecular weight (Mn) obtained via vapor pressure osmometry (VPO) technique. For example, the Mn obtained for palm olein polyol E‐135 calibrated against polyether polyols was 2,537 Da, which was closer to the Mn via VPO (1,618 Da), than the Mn obtained using PS as calibration standards (3,836 Da). Hence, this GPC analysis using polyether polyols as calibration standards can offer reassured determination of MWD of palm olein polyols.