The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length a...The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.展开更多
Dodecyl benzenesulfonic acid(DBSA)surfactant was used in the present study to find the effect of concentrationon its electrical conductance in solution from 293-323 K above and below the critical micelle concentration...Dodecyl benzenesulfonic acid(DBSA)surfactant was used in the present study to find the effect of concentrationon its electrical conductance in solution from 293-323 K above and below the critical micelle concentration(CMC).Themicellization parameters i.e.degree of counter ion binding(β),aggregation number(n)and number of counter ion micelle(m)were measured.The interaction of DBSA with polyvinylpyrrolidone(PVP)was also studied at 293 K throughconductance and surface tension measure ments.A number of important parameters i.e.critical aggregation concentration(CAC),Gibb's free energy(△G)and binding ratio(R)were determined and the effect of NaCl on the CAC and polymersaturation point(PSP)was also investigated.展开更多
Palm C16 methyl ester sulphonate （C16MES）is an anionic surfactant that has the potential as active ingredient in the production of laundry detergent powders. Although C16MES has been successfully applied in the prod...Palm C16 methyl ester sulphonate （C16MES）is an anionic surfactant that has the potential as active ingredient in the production of laundry detergent powders. Although C16MES has been successfully applied in the production of high-density laundry detergent powders （HDDP）, it coulingd not be employed directly as it is in the spray drying process for the production of low-density laundry detergent powders （LDDP） without compromising the detergency and other significant properties. This research paper highlights the pilot-scale experimental study, which performed to produce phosphate-free laundry detergent （PFD） powders incorporated with binary anionic surfactants of C16MES and linear alkyl benzene sulphonic acid （LABSA）. Past laboratory experiments revealed that PFD powders resulted from C16MES/LABSA of 50：50 ratio and of pH 7-8 have good detergency stability upon one-week of continuous heating in an oven at 50~C with 85% relative humidity. Based on these laboratory results, subsequent experiments were carded in a 5 kg/hr capacity co-current pilot spray dryer using PFD formulations comprising six different ratios of C16MES/LABSA （0：100, 20：80, 40：60, 80：20 and 100：0） under the same pH condition. Three PFD formulations were selected for further evaluation based on their characteristics in the spray drying process. The cleaning properties and particle properties of the resulting spray dried detergent powders from these selected formulations were analyzed. Based on the overall evaluation, C16MES/LABSA in 40：60 ratio was selected as the ideal PFD formulation. Further tests confirmed that spray dried detergent powder （SDDP） from the ideal formulation has high level of biodegradability （60% in 13 d）, low eco-toxicity properties （LC50 of 11.3 mg/L） and moderate flowability charactedsUcs （Hausner ratio of 1.27 and Carr＇s index of 21.3）.展开更多
文摘The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.
文摘Dodecyl benzenesulfonic acid(DBSA)surfactant was used in the present study to find the effect of concentrationon its electrical conductance in solution from 293-323 K above and below the critical micelle concentration(CMC).Themicellization parameters i.e.degree of counter ion binding(β),aggregation number(n)and number of counter ion micelle(m)were measured.The interaction of DBSA with polyvinylpyrrolidone(PVP)was also studied at 293 K throughconductance and surface tension measure ments.A number of important parameters i.e.critical aggregation concentration(CAC),Gibb's free energy(△G)and binding ratio(R)were determined and the effect of NaCl on the CAC and polymersaturation point(PSP)was also investigated.
文摘Palm C16 methyl ester sulphonate （C16MES）is an anionic surfactant that has the potential as active ingredient in the production of laundry detergent powders. Although C16MES has been successfully applied in the production of high-density laundry detergent powders （HDDP）, it coulingd not be employed directly as it is in the spray drying process for the production of low-density laundry detergent powders （LDDP） without compromising the detergency and other significant properties. This research paper highlights the pilot-scale experimental study, which performed to produce phosphate-free laundry detergent （PFD） powders incorporated with binary anionic surfactants of C16MES and linear alkyl benzene sulphonic acid （LABSA）. Past laboratory experiments revealed that PFD powders resulted from C16MES/LABSA of 50：50 ratio and of pH 7-8 have good detergency stability upon one-week of continuous heating in an oven at 50~C with 85% relative humidity. Based on these laboratory results, subsequent experiments were carded in a 5 kg/hr capacity co-current pilot spray dryer using PFD formulations comprising six different ratios of C16MES/LABSA （0：100, 20：80, 40：60, 80：20 and 100：0） under the same pH condition. Three PFD formulations were selected for further evaluation based on their characteristics in the spray drying process. The cleaning properties and particle properties of the resulting spray dried detergent powders from these selected formulations were analyzed. Based on the overall evaluation, C16MES/LABSA in 40：60 ratio was selected as the ideal PFD formulation. Further tests confirmed that spray dried detergent powder （SDDP） from the ideal formulation has high level of biodegradability （60% in 13 d）, low eco-toxicity properties （LC50 of 11.3 mg/L） and moderate flowability charactedsUcs （Hausner ratio of 1.27 and Carr＇s index of 21.3）.
