A STUDY ON THE DEGRADATION MECHANISM OF PHOTOCROSSLINKING PRODUCTS FORMED BY CYCLIZED POLYISOPRENE-DIAZIDE SYSTEM UNDER THE INFLUENCE OF ALKYL BENZENE SULFONIC ACIDS

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.

MICELLIZATION STUDIES OF DODECYL BENZENESULFONIC ACID AND ITS INTERACTION WITH POLYVINYLPYRROLIDONE

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.

HYDROXYLATION OF BENZENE BY HETEROPOLY ACIDS(SALTS)CONTAINING VANADIUM

Direct hydroxylation of benzene catalyzed by vanadium-con- taining heteropoly compounds with Keggin or Dawson structure has been investigated.The effects of several factors upon the hydroxylation reaction have also been examined.It is indicated that the highest yield of phenol reached 76%(based on H_2O_(?))with 99.4～100% selectivity.

Structure and Photophysical Properties of a Chiral 4-Fold Interpenetrated Zn(Ⅱ) Coordination Polymer Tuned by 4,4'-(Hexafluoroisopropylidene)bis(benzoic acid)and 1,3-Di(pyridineyl)benzene

A new three-dimensional（3D） chiral metal-organic coordination polymer, [Zn（dpb）（hfipbb）]n, was obtained under hydrothermal conditions by 1,3-di（pyridineyl）benzene（dpb） and 4,4-（Hexafluoroisopropylidene）bis（benzoic acid）（H2hfipbb）. The as-prepared sample was characterized by single-crystal X-ray diffraction, PXRD, elemental analysis, IR spectroscopy and TGA analysis. The title coordination polymer crystallizes in orthorhombic, space group P21212, with a=21.923（4）, b=23.594（4）, c=7.3042（13） , V=3778.1（12） 3, Dc=1.209 g/cm3, Mr=687.90, F（000）=1328, μ=0.713 mm（-1） and Z=4. The compound contains two types of helical chains [Zn（hfipbb）]n and [Zn（dpb）]n which are linked with each other to generate a 3D framework by sharing the same Zn（Ⅱ） cations. It displays a 4-fold interpenetrated 3D framework. In addition, the luminescence, fluorescence lifetime and the second harmonic generation（SHG） efficiency properties in the solid state have been studied.

A novel method for producing benzene polycarboxylic acids by electrochemical oxidation of Zhaotong lignite in aqueous NaCl solution

The development of a coal-based synthetic route to produce benzene polycarboxylic acids(BPCAs)is of great importance for the highly efficient utilization of lignites.In this paper,aqueous NaCl^(-)electrolytic system was used to oxidize Zhaotong lignite to prepare BPCAs.The electrochemical oxidation of lignite in aqueous NaCl solution could produce more BPCAs than that in aqueous NaOH solution.The aqueous NaCl electrolytic system could in-suit produce a stable OCl^(-),which was synthesized by the combination reaction between Cl_(2)and OHgenerated in the anode or cathode,respectively.The in-suit produced OCl^(-)would degrade the organic structures of the lignite dispersing in the electrolyte to generate BPCAs.The formation of BPCAs could be greatly affected by current density,electrolysis time and the addition amount of NaCl in the electrolytic system,which resulted from that the factors played an important role in the generation of OCl^(-).The coal related model compounds including anthracene and phenanthrene were used to investigate the electrochemical oxidation mechanism of the lignite.The results indicated that the aromatic ring structures in the lignite were attacked by O_(2)•^(-)from the OCl^(-)to afford BPCAs.

Syntheses, Structures, and Luminescent Properties of Two ZnⅡ-organic Polymers Based on [Zn（ox）]n Chains and Different Imidazole Linkers

Hydrothermal reactions of two imidazole derivatives （1,3,5-tib = 1,3,5-tris（1H- imidazol- 1 -yl）benzene, 1,4-bimb = 1,4-bis（1 H-imidazol- 1 -ylmethyl）benzene） and the ZnⅡ cations in the presence of oxalic acid （H2ox） afford two coordination polymers, namely, {[Zn（ox）（1,3,5- tib）]·2（H20）}n （1） and [Znl.5（OX）1.5（1,4-bimb）l.5]n （2）. Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and powder X-ray diffraction （PXRD） analyses. Both complexes 1 and 2 are based on the 1D zigzag [Zn（ox）]n chains, and their final structures are controlled by the two different imidazole linkers, which expanded the structure along different directions, finally giving a 3D dia net for 1 and a 2D sql layer for 2. Moreover, the luminescent properties of 1 and 2 have been investigated.

Fluorescence Quenching Method for Determination of Cu^(2+) with Tb-TMA System in Presence of Triton X-100

A fluorescence quenching system of Cu 2+ Tb TMA Triton X 100 (TMA: benzene 1,3,5 tricarboxylic acid) was established for the determination of Cu 2+ . The fluorescence intensity of the determination system is linear in the concentration range of 1.58×10 -7 ～2.83×10 -5 mol·L -1 Cu 2+ . The proposed method was applied to the determination of Cu 2+ contained in various copper ores with satisfactory results.

Recent Development on Zero-Phosphate Spray Dried Detergent Powders Incorporated with Palm C16 Methyl Ester Sulfonates

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）.

Effect of pyrolysis on Zhaotong lignite oxidation with aqueous sodium hypochlorite

The pyrolysis treatment of lignites could remove thermal-unstable aliphatic structures but enrich aromatic structures in resulting pyrolysis residues,which would facilitate producing benzene polycarboxylic acids(BPCAs).Herein,the demineralized Zhaotong lignite(DZL)was pyrolyzed at 250-550℃ to afford the corresponding pyrolysis residues.Subsequently,DZL and its pyrolysis residues were subjected to oxidation with aqueous sodium hypochlorite.By XRD,FTIR,and element analyses,it was found that the content and polycondensation degree of aromatic structures simultaneously increased with increasing pyrolysis temperature.Furthermore,the yield and selectivity of BPCAs both increased along with raising pyrolysis temperature in resulting products from fully oxidation of DZL and its pyrolysis residues.Based on the distribution of BPCAs,peri-condensed aromatic structures were dominant in DZL and its DPRs,and obviously increased with increasing pyrolysis temperature.More interestingly,good correlation was found between the yield of BPCAs and aromaticity parameters.Meanwhile,the yield of benzenepentacrboxylic acid was well associated with polycondensation degree parameters.