Separation of phenolic compounds from coal tar oil has good commercial value. In this paper, we tried to use the H-bonding or Lewis acid–base interaction to chemically adsorb phenolic compounds that were both Brønsted acid and Lewis base. Hexamethylenetetramine (HMT), 1,2,4-triazole, and AlCl3 were selected as sorbents, and their adsorptive behavior were studied experimentally and theoretically. These sorbents can adsorb phenol from n-hexane oil. HMT showed the amazing phenol adsorbance (Qe,max>3500mg/g), non-corrosiveness, stable physical state, good recycling, and oil-insoluble merit. In contrast, AlCl3 was unrecoverable and triazole was partially oil-soluble, and thus they were not as good as HMT. Further, naphthalene or benzothiophene hardly hinders phenol adsorption on HMT (Qe,max>3400mg/g in 5wt% benzothiophene or naphthalene oil); whereas, quinoline interfered with the adsorption (Qe,max>970mg/g in 5wt% quinoline oil). Therefore, HMT might be an excellent sorbent for phenol, showing the best capacity heretofore.

To develop a greener process for reclaiming phenolic compounds from low temperature coal tar, extractive performance of twelve extractants, including mono-, di-, and triethanol amines (MEA, DEA, TEA), six protonated ionic liquids (ILs) thereof with formate (FA) or acetate (Ac) anion, choline chloride, and two polyols (glycol, glycerol), were studied at varying conditions, along with the back extractability of phenols by ether. The extraction performance is MEA > DEA > TEA approximate to ILs > glycol > glycerol, while the back extraction performance of ether is just the opposite. The coexistent toluene in oil and temperature show a little influence on the extraction performance of alcoholic amines and their corresponding ILs. The extraction performance of extractants is consistent with their complexability with phenol, i.e. ethanol amines > ether > ILs > polyols, as manifested by the red shift of the UV spectrum of phenol in the above solvents. [HMEA]FA is the most promising extractant for its overall extraction performance, cheapness, and other favorable physical attributes.

Lewis-Bronsted complex acid, such as BF3, SnCl4, FeCl3, or ZnCl2-CH3COOH, can enhance thiophenic compound oxidation using solid oxidants. The catalytic oxidative mechanism was studied here. For the catalysis of the complex acid system, Lewis acid was the core, improving the Bronsted acidity of the system, promoting the dissolution of oxidant in the system, and finally catalyzing the oxidation of sulfur in the oil. For the oxidation of thiophenic compound, dibenzothiophene (DBT) was oxidized to its sulfone, but benzothiophene (BT) and thiophene (T) were oxidized to some unidentified products besides the sulfones or sulfoxides. These unidentified products originated from the oxidation of unsaturated bonds on thiophenic compounds. The electronic property of unsaturated bonds, which included bond order and pi orbital occupancy, was used to explain the reactivity of unsaturated bonds on those compounds. On the basis of mechanism obtained, the catalysis for the oxidation of sulfur against olefins was controlled. (C) 2013 Elsevier B.V. All rights reserved.

Random copolymers of poly(styrene-co-isopropenyl acetate) (SIPA) with an average number of 9 initiating sites per chain were synthesized by free radical copolymerization of styrene with a small amount of isopropenyl acetate using 2,2'-azo-bis-(isobutyronitrile) as an initiator at 70 degrees C. SIPA copolymer could be further used as macroinitiator for the grafting cationic polymerization of isobutylene (IB) from SIPA chain in CH2Cl2 at -40 degrees C to produce graft copolymers of SIPA-g-PIB. The effect of SIPA concentration ([SIPA]), TiCl4 concentration ([TiCl4]) and IB concentration ([IB]) on initiation efficiency of macroinitiator, grafting efficiency of initiating sites, average length of PIB branches of the resulting graft copolymers were investigated. It can be found that almost all of the initiating sites of IPAc units on SIPA chains were active for the cationic polymerization of IB and both initiation efficiency and grafting efficiency were close to 100% at sufficient molar ratio of TiCl4/IPAc. This synthetic route presents quantitative grafting efficiency and possibility to control length of PIB branches. The graft copolymers of SIPA-g-PIB with average 9-branched PIB chains having terminal functional tert-chlorine groups could be successfully obtained. The average molecular weight of PIB branches in SIPA-g-PIB graft copolymers could be mediated from 3900 to 47,300 g mol(-1) by changing the ratios of macroinitiator to monomer and concentration of TiCl4. (C) 2012 Elsevier Ltd. All rights reserved.

The copolymerization of 4-vinylbenzyl chloride (VBC) and vinyl acetate (VAC) was carried out in toluene at 75°C via radical polymerization using 2,2′-azo-bis-(isobutyronitrile) (AIBN) as an initiator. The random copolymers of poly(4-vinylbenzyl chloride-co-vinyl acetate) (P(VBC-co-VAC)) with number average molecular weight (M n) from 2000 to 6900, relatively narrow molecular weight distribution (MWD, M w/M n ca. 2.0) and with different copolymer composition of 4-vinylbenzyl chloride (VBC) from 17 mol% to 62 mol% could be obtained. The P(VBC-co-VAC) copolymers with an average number of 7 to 13 initiating sites of benzyl chloride per macromolecule could be used for the cationic polymerization of isobutylene (IB). The cationic polymerizations of IB were further conducted by using P(VBC-co-VAC) copolymers as macroinitiators in conjunction with TiCl4 at −40°C in CH2Cl2. The effects of VBC/TiCl4 (molar ratio) on monomer conversion, M n and MWD of the resultant copolymers were investigated under 3 sets of conditions. It is found that P(VBC-co-VAC)-g-PIB copolymers with relatively narrow MWD (M w/M n ca. 2.0) and with terminal tert-chlorine functional groups in branched PIB chains could be successfully synthesized when VBC/TiCl4 (molar ratio) was set in the range from 0.10 to 1.12. The unimodal GPC curve of the P(VBC-co-VAC)-g-PIB copolymers by RI detector was almost in harmony with the GPC curve by UV detector. The TEM image of the P(VBC-co-VAC)-g-PIB copolymer stained by RuO indicated that the copolymer formed a two-phase morphology with P(VBC-co-VAC)-rich domains of 20–100 nm in size tethered by PIB branch segments.

The mechanism and new stage in controlled/living cationic polymerization of vinyl monomers, such as isobutylene, styrene, vinyl ether, are reviewed. The novel initiating systems including metallocene, Lewis acid with a weak base, Lewis acidic diboranes, water-tolerant acid, and the cationic polymerization in aqueous media are summerized. The advanced thermoplastic elastomer based on polyisobutylene via controlled/living cationic polymerization is used as biomaterials.