Divinylbenzene Units Research Articles

Novel Solution to Oil Spill Recovery: Using Thermodegradable Polyolefin Oil Superabsorbent Polymer (Oil–SAP)

This paper discusses a novel approach that may provide a complete solution to combating oil spills. The technology is centered on a cross-linked polyolefin terpolymer (x–OS–DVB), containing 1-octene, styrene, and divinylbenzene units, which is an oil superabsorbent polymer (oil–SAP) with aliphatic and aromatic side chains that have similar solubility parameters (oleophilic and hydrophobic properties), with the hydrocarbons in crude oil. Some x–OS–DVB terpolymers, with desirable morphology (amorphous, low Tg, and high free volume) and lightly cross-linked (complete network) structure, show rapid oil absorption and swelling to reach a capacity 45 times their weight. The capacity of oil uptake (swelling) is inversely proportional to the cross-linking density. The combination of selective oil absorption (without water) and tough mechanical strength offers buoyancy, stability, and easy recovery on water surfaces. The recovered oil-swelled gel, containing more than 98% oil and 2% x–OS–DVB, is suitable for regular oil-refining processes (an economic, no waste, and no pollutant approach). The bulk side chains in x–OS–DVB result in a relatively low ceiling temperature for depolymerization and zero heating residue at 450 °C, well below the first distillation step (>600 °C) in oil refining. Furthermore, polyolefins are the most inexpensive polymeric material, with a large production capability around the world. Overall, this cost-effective new polyolefin oil–SAP technology shall dramatically reduce the environmental impacts from oil spills and help recover one of our most precious natural resources.

Polystyrene Microgel Amphiphiles with Maltohexaose. Synthesis, Characterization, and Potential Applications

4-Vinylbenzyl maltohexaoside peracetate (1) was copolymerized with divinylbenzene (DVB) using 1-phenyl-1-(2',2',6',6'-tetramethyl-1'-piperidinyloxy)ethane (2) in m-xylene. The copolymerizations were performed at 138 degrees C for 20 h using the mole fraction of 1 in the total feed of 1 and DVB (F1: [1]/[1]+[DVB]) varying from 0.11 to 0.38, affording polymeric products in yields ranging from 32 to 40%. The characterizations by linear PS-calibrated size exclusion chromatography (SEC), dynamic laser light scattering (DLS) measurements, and 1H NMR spectroscopy indicated that the product was assignable to the cross-linked poly(4-vinylbenzyl maltohexaoside peracetate) particle which is able to produce stable solutions, i.e., the PSt microgel with acetyl maltohexaose, 3. The specific rotations ([alpha]D23, c = 1.0 CHCl3) of 3 ranged from +43.3 degrees to +85.6 degrees. The average molar masses determined by the static laser light scattering (SLS) measurement of 3, M(w,SLS)'s, were from 64,700 to 118,000, which were calculated using the respective refractive index increments, dn/dc's, ranging from 0.03387 to 0.08340. The apparent numbers of the 1, 2, and DVB units in 3, N1, N2, and N(DVB), which were estimated from the respective [alpha]D23 values, M(w,SLS)'s, and real yields, ranged from 22 to 35, from 7 to 26, and from 146 to 506, respectively. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the PSt microgel with maltohexaose as the hydrophilic segment, 4, as a white solid. The solubility of 4 in various solvents was examined, indicating that a hydrophilic property was effectively introduced. Notably, 4 gave clear solutions in the mixed solvent of 1,4-dioxane and H2O. The ability to solubilize fullerite (mixture of fullerenes, C60/C70 = ca. 9/1) in aqueous solutions was examined according to the literature method. Approximately, 100 mg of 4 (1.7 micromol) solubilizes 1.3 mg of fullerite (1.7 micromol).

Synthesis of polystyrene microgel with glucose as hydrophilic segment via controlled free-radical polymerization

4-Vinylbenzyl glucoside peracetate (1) was copolymerized with divinylbenzene (DVB) using 1-phenyl-1-(2′,2′,6′,6′-tetramethyl-1′-piperidinyloxy)ethane (2) as an initiator in m-xylene at 138°C for 20h ([DVB]/[2]=28; [DVB]=0.62molL−1). The copolymerizations were performed using the mole fraction of 1 in the total feed of 1 and DVB (F1: [1]/[1]+[DVB]) ranging from 0.11 to 0.38 that produced the polystyrene (PSt) microgel with acetyl glucose, 3, in 46–53% yields. Dynamic laser light scattering (DLS) measurements showed that 3 was stably suspended in toluene as particles with average diameters (d's) ranging from 12 to 22nm. A static laser light scattering (SLS) measurement gave the average molar mass, Mw,SLS, of 3 that ranged from 9.69×104 to 6.96×105. The numbers of the 1, 2, and DVB units in 3 (N1, N2, and NDVB, respectively) were from 111 to 238, from 17 to 208, and from 350 to 4510, respectively. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the PSt microgel with glucose as the hydrophilic segment, 4. The solubilities of 4 in toluene, CHCl3, THF, 1,4-dioxane, pyridine, DMF, DMSO, and H2O, and the mixture of H2O and 1,4-dioxane were examined, indicating that a hydrophilic property had been effectively introduced into 4.

Preparation of hyperbranched copolymers containing triphenylamine and divinylbenzene units

In the presence of palladium(II) acetate, the coupling reaction of tris(4-bromophenyl)amine 1 and p-divinylbenzene 2 gave a hyperbranched conjugated copolymer 4 in a one step process and in a high yield. Polymer 4 was soluble in organic solvents such as THF and chloroform. GPC indicated that it had an average molecular weight of 5.1 × 10 3. A cast film had an anodic peak at 1.05 V vs Ag wire. It was blue above the oxidation potential and light-yellow in the neutral state.

Effect of nitrobenzene on initiator-fragment incorporation radical polymerization of divinylbenzene with dimethyl 2,2′-azobisisobutyrate

The polymerization of divinylbenzene (DVB) with dimethyl 2,2′-azobisisobutyrate (MAIB) was conducted at 70 and 80°C in benzene in the presence of nitrobenzene (NB) as a retarder. When the concentrations of DVB, MAIB, and NB were 0.45, 0.50, and 0.50mol/l, respectively, the polymerization proceeded without any gelation to yield soluble polymers. The polymer yield (up to 65%) and the molecular weight (Mn=1.5–4.2×l04 at 70°C and 1.3–3.9×l04 at 80°C) increased with time. The polymer formed in the polymerization at 80°C for 4h consisted of the DVB units with (4mol%) and without double bond (41mol%), methoxycarbonylpropyl group as MAIB-fragment (48mol%), and NB unit (7mol%). Incorporation of such a large number of the initiator-fragments as terminal groups in a polymer molecule indicates that the polymer is of a hyperbranched structure. The polymer showed an upper critical solution temperature (40°C on cooling) in an acetone-water [14:1 (v/v)] mixture. The results of MALLS and viscometric measurements and TEM observation supported that the polymers formed in the present polymerization have a hyperbranched structure. The polymerization system at 70°C involved an ESR-observable nitroxide radical formed by the addition of polymer radical to the nitro group of NB. The polymerization was kinetically investigated in dioxane. The initial polymerization rate (Rp) at 70°C was expressed by Rp=k[MAIB]0.5[DVB]0.9[NB]−0.4. The kinetic results were explained on the basis of the reversible addition of polymer radical to NB and the termination between the polymer radical and the nitroxide radical. The overall activation energy of the polymerization was 27.8kcal/mol.

Synthesis of Linear Polyolefin Elastomers Containing Divinylbenzene Units and Applications in Cross-Linking, Functionalization, and Graft Reactions

This paper discusses the synthesis of linear polyolefin elastomers containing divinylbenzene (DVB) units, including poly(ethylene-ter-propylene-ter-divinylbenzene) (EP-DVB) and poly(ethylene-ter-1-octene-ter-divinylbenzene) (EO-VDB). Several metallocene catalysts were evaluated to identify a system that can carry out monoenchainment of DVB and produce terpolymer with uniform molecular structure. Some resulting EP-DVB and EO-DVB terpolymers prepared by a rac-Et(Ind)2ZrCl2/MAO catalyst show good solubility in common organic solvents, controllable DVB content, high molecular weight, and narrow molecular weight and composition distributions. The uniform terpolymer microstructure also exhibits a DSC curve with a sharp glass transition temperature (Tg) that corresponds to its composition. Some EP-DVB and EO-DVB terpolymers with DVB content <2 mol % show low Tg's, below −45 and −55 °C, respectively. In turn, the pendent styrene moieties in the terpolymers are very versatile and engage in facile thermal and UV cr...

Synthesis and characterization of novel luminescent polymers with alternate phenothiazine and divinylbenzene units

AbstractNovel luminescent polymers (P1 and P2) carrying alternate phenothiazine and divinylbenzene units were synthesized via the Wittig reaction. Absorption, fluorescence, and cyclic voltammetric methods were applied to investigate their optical and electrochemical properties. The photoluminescence (PL) maxima of P1 and P2 were 559 and 568 nm, respectively. Compared with reported hole‐transport groups such as carbazole, alkyldiphenylamine, triphenylamine, and iminodibenzyl chromophores, phenothiazine moieties in P1 and P2 bathochromically shift the PL maxima and narrow the band gaps. Their relative PL efficiencies were about 0.5 and 0.3 in solution and in the film state, respectively. Moreover, highest occupied molecular orbitals of P1 (4.78 eV) and P2 (4.74 eV) were even higher than the work function of ITO electrode (4.8 eV). The threshold electric fields of the Al/P1 (or P2)/ITO device were about 1.52–1.63 · 106 V/cm, which were smaller than 1.73 · 106 V/cm of P3, consisting of alternate iminodibenzyl and divinylbenzene units. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4452–4462, 2002

Heterogeneities of styrene-divinylbenzene-copolymers

The heterogeneity of copolymers of styrene and divinylbenzene was investigated. The distribution of divinylbenzene units within the crosslinked copolymer yields information about the inhomogeneity of the network formed. Proceeding from the monomer reactivity ratios, the monomer compositions and from the conversion we set up histogramms of the distribution of the divinylbenzen-isomers within the formed copolymers. As a mathemathical expression of heterogeneity we used the relative variance. Possibilities to influence the heterogeneities found are discussed.

Debromination of di- and tetrabrominated compounds by crosslinked poly{1-[ p-(mercaptomethyl)phenyl]ethylene}

Poly{1-[ p-(mercaptomethyl)phenyl]ethylene} with a low content of divinylbenzene units as the crosslinking component was prepared from chloromethylated poly(styrene-co-divinylbenzene), and the activity of the thiolate form in the debromination reactions of 1,2-dibromocyclohexane was investigated with respect to the analytical content of the -SH groups. The extent of transformation of the -SH groups into the thiolate form, and the degree of crosslinking of the polymeric carrier were investigated. An almost complete conversion of 1,2-dibromocyclohexane and high yields of cyclohexene were obtained by using polymeric thiols with the initial DVB contents of 1 or 2%; the degree of functionalization of the carrier 100% or 30–60%; and the reaction times of polymeric thiols with sodium methoxide in methanol (1–2h). The debromination reaction required 5h for completion. Under optimum conditions, debromination of 1,2,5,6-tetrabromocyclooctane, α,β-dibromoethylbenzene, α,β,3,4-tetrabromoethylcyclohexane, diethyl2,3-dibromosuccinate and stilbene dibromide gave olefins in yields of 60–100%

Vinyl-Divinyl Copolymerization: Copolymerization and Network Formation from Styrene and p- and m-Divinylbenzene

Abstract The composition of copolymers of p- and m-divinylbenzene with styrene was determined by infrared spectrometry during copolymerization and compared with values calculated on the assumption that the polymerizing system is homogeneous, and the reactivities both of the vinyl groups in the monomers and of the pendant vinyl groups are independent of the extent of copolymerization. At lower conversions the content of all divinylbenzene units, and especially that of the pendant vinyl groups in the copolymer, is lower than calculated, whereas at higher conversions a fraction of pendant vinyl groups does not react. The conversions at the gel point do not depend on the concentration of divinylbenzene; at higher percentages of the divinyl monomer or dilution of the system they are higher for p- than for m-divinylbenzene, although p-divinylbenzene copolymers contain more divinylbenzene units at the same conversion. The deviations are explained by inhomogeneous copolymerization caused by locally different conc...

The preparation of some block copolymers

AbstractThe reactivity of the double bonds in p‐divinylbenzene toward anionic reagents is much greater than is the residual double bond in the divinylbenzene unit incorporated in a polymer chain. Thus it is possible to add to a “living” polymer a few divinylbenzene units before appreciable crosslinking occurs. Each of these units will have a vinyl group conjugated with a phenyl ring and will be comparable in reactivity to styrene. If the reaction is stopped at this point by the addition of methanol, the molecular weight of the product is essentially that of the original living polymer. These polymers may then be copolymerized through these active double bonds with any monomer with which styrene may be copolymerized, to form block or graft‐like copolymers. The copolymerizations may be effected by any of the methods applicable to styrene, i.e., free radical, cationic, or anionic. Such copolymerizations have been attempted with methyl methacrylate, butyl acrylate, vinyl chloride, vinylidene chloride, vinyl acetate, butadiene, isobutene, and propene, usually successfully.