Chloromethylstyrene-divinylbenzene

Nagakawa and co-workers [47] applied Py-GC to a structural study of various chloromethyl substituted PS copolymers prepared by different methods and they applied (TGA) gravimetric analysis to the dehydrochlorination and thermal degradation behaviour of these copolymers. Typical pyrograms of ST-DVB, styrene-chloromethylstyrene-divinylbenzene (ST-Cl-MST-DVB and chlorinated p-methyl styrene divinylbenzene copolymers are shown in Figures 1.5-1.7. 

Grafting of these preformed monoliths with dormant radicals is achieved by filling the pores with a monomer solution and heating to the desired temperature to activate the capped radicals. For example, a functionalization of poly(styrene-divinylbenzene) monolith with chloromethylstyrene and vinyl-pyridine to obtain material with up to 3.6 mmol/g of functionalities has been demonstrated [88]. 

Horvath s group has recently reported the preparation of porous rigid monolithic capillary columns for CEC by polymerizing mixtures of chloromethylstyrene 21, divinylbenzene 22 and azobisisobutyronitrile in the presence of various porogenic solvents such as methanol, ethanol, propanol, toluene, and formamide [49]. The capillary wall was silanized using a 50% dimethylformamide solution of 3-(trimethoxysilyl)propyl methacrylate 8 at a temperature of 120°C for 6 hours. In order to avoid the spontaneous polymerization of the functional methacrylate, a stable free radical (DPPH) was added to the solution. The SEM micrographs of Fig. 6.16... 

A low purity (40-80%) divinylbenzene and chloromethylstyrene were used in the presence of a Friedel-Crafts catalyst (AICI3) for the synthesis of a polymeric phenolic antioxidant from p-cresol and l,3-bis(l-hydroxy-l-methylethyl)benzene in the presence of p-toluene sulfonic acid [115]. The obtained product was either used directly as AO for thermosetting resins or was treated consecutively with a-methylstyrene [116] or /ert-butylalcohol [117]. Other polymeric phenolic AO were obtained by reaction of phenol with p-men thane-1,8-diol, l-p-menthen-8-ol or limonene [118] or of p-cresol with 3- or 4-chloromethylstyrene in the presence of BF3-etherate or anhydrous AICI3 [119] the product thus obtained was finally aralkylated by a-methylstyrene. Thermostabilizer and/or LS for PUR was obtained, e.g. 98. 

In another approach, reactive monodisperse porous poly(chloromethylstyrene-co-styrene-co-divinylbenzene) beads have been employed for the preparation of chiral HPLC packings. Thus, reactive chloromethyl groups were derivatized to yield amino functionalized beads onto which both rt-basic and rt-acidic type chiral. selectors, (/ )- -(l-naphthyl)ethylamine and (/ )-A -(3.5-dinitrobenzoyl)phenylglycine, respectively, were attached. The resulting chiral particles were chromatographically tested for the enantioseparation of model SAs. Despite the presence of strongly competitive it-TT-binding sites of the styrenic support these chirally modified beads afforded baseline separations for 2,2,2-trifluoro-l-(9-anthryl) ethanol and Af-(3.5-dinitro-benzoyl) leucine enantiomers, respectively [369. ... 

As a new macromolecular backbone of immobilized artificial enzymes, we have prepared poly(chloromethylstyrene-co-divinylbenzene) (PCD) (36). Here, chlo-romethylstyrene monomer contains ca. 70% and 30%, respectively, of meta- and para-isomers and divinylbenzene is a mixture of isomers. Divinylbenzene serves as a cross-linking group and, therefore, PCD is highly branched. The shape of PCD synthesized with 2 mol% of divinylbenzene taken by scanning electron microscopy is illustrated in Figure 1. 

When the Cu(II) complex of cyclen (AE) was attached to cross-linked polystyrene, the proteolytic activity of the Cu(II) complex of cyclen was enhanced remarkably (111). Poly(chloromethylstyrene-co-divinylbenzene) (PCD) was prepared as a derivative of polystyrene in which all of the styryl residues contained chloromethyl groups. By the substitution of chloro groups of PCD with various nucleophiles, PCD derivative BA was prepared. y-Globulin was hydrolyzed upon incubation with BA, whose half-life was as short as 1 h at 25°C and pH 7 in the presence of excess BA. The rates for hydrolysis of y-globulin by the Cu(II) complex of cyclen itself dissolved in water were also measured. Comparison of rate data collected at the same catalyst concentrations revealed that the proteolytic activity of the Cu(II) complex of cyclen was... 

Ac = Polyacrylamide Cycl = Cyclodextrin PE = Polyethylene PEO = Oxidized polyethylene PS = Polymer derived from p-chloromethylstyrene PS,b = Polymer derived from styrene and (7-bromoheptyl)styrene PS,b = Polymer derived from styrene and 4-bromobutyl)styrene PS,c = Polymer derived from styrene, p-chloromethylstyrene and divinylbenzene PS,f = Polymer derived from crosslinked polystyrene and polypropylene fibers. 

Example 2. Acrylonitrile-butadiene rubber (5 wt.%) is dissolved in a mixture of chloromethylstyrene (82 wt.%) and divinylbenzene (10 wt.%) (mixture of o- and p-divinylbenzene). After benzoyl peroxide (3 wt.%) is dissolved in the mixture, the obtained pasty mixture is coated on a woven-cloth fabric made of poly(vinyl chloride) and polymerized at 80 °C for 16 h under nitrogen atmosphere, covered with a polyester film and then pressed with steel plates on both sides. After polymerization, the obtained membranous copolymer is immersed in trimethylamine (1 mol) mixed with acetone (25 wt.%) and water (75 wt.%) solution for 24 h at 30 °C to react with the chloromethyl groups of the membrane.37... 

K. Kusumoto, T. Sata and Y. Mizutani, Copolymerization of chloromethylstyrene and divinylbenzene in the absence or presence of poly(vinyl chloride), J. Macromol. Sci., Chem., 1987, A24, 645-659 Y. Kagiyama, K. Shikata and Y. Mizutani, Copolymerization of styrene-divinylbenzene in the presence of poly(vinyl chloride), J. Appl. Polym. Sci., 1979, 23, 1309-1318. 

To further confirm the effect of the tightness of the anion exchange membrane on permselectivity between anions, anion exchange membranes have been prepared by the reaction scheme shown in Figure 5.22.91 Namely, copolymer membranes composed of chloromethylstyrene and divinylbenzene are reacted with 4-vinylpyridine to form poly(4-vinylpyiridinium) in the cross-linked membrane matrix and then with trimethylamine to aminate the remaining chloromethyl... 

Chloromethylated resins were also synthesised by copolymerisation of styrene, divinylbenzene and chloromethylstyrene 7.83.84 (usually as a 3 2-mixture of meta and para isomers). Arshadi et al. noticed, however, that this approach can lead to substantial losses of chlorine content... 

Poly(styrene-co-chloromethylstyrene) crosslinked with divinylbenzene, which is immobilized with quaternary ammonium salts, was investigated for the synthesis of the fine chemicals in our previous studies [161-166]. The microenvironment of the polymer support played a crucial role in enhancing the reaction rate. More information about characterization of the polymer structure, the interaction between organic solvent, resin, and aqueous solution, and the reuse of the catalyst is required to encourage application. 

For the separation of peptides and proteins followed by MALDl-TOF-MS detection, porous polymer monoliths were prepared by UV-initiated photografting of the respective monomer solutions. Plates were produced as 50- to 200-pm thin poly(butyl methacrylate-co-ethylene dimethacrylate) layers and as 50-pm thin poly(glycidyl methacrylate-co-ethylene dimethacrylate) layers with a gradient of hydrophobic-ity for 2D separations [13,14]. Thermally initiated polymerization was used for the production of 50-pm thin poly(4-methylstyrene-co-chloromethylstyrene-co-divinylbenzene) layers. The specific surface area of this styrene-containing polymer was further increased by hypercrosslinking via Friedel-Crafts alkylation, resulting in a higher separation performance [15]. 

These polymers constitute the largest group to be discussed in this report and this is mainly because polystyrene and poly(chloromethylstyrene), often crosslinked with divinylbenzene, continue to be widely used in the preparation of functional polymers and resin-supported reagents. In fact most of the examples given here refer to the preparation of functional polymers rather than to new materials. This is a rapidly growing area of polymer chemistry and it is not possible to refer, in a compressed review of this nature, to all reports of functionalized styrene-based resins that have appeared in the past two years. This section falls naturally into three parts the first deals with styrene polymers and copolymers, the second with reactions on chloromethylated polystyrenes, and the third deals with styrene-related polymers. 

Most investigations of polymer-supported onium ion phase transfer catalysts have used cross-linked polystyrenes. Not all of them have the same structure, even when they have the same formal degree of cross-linking with divinylbenzene. (The effect of percent cross-linking is considered in a later section). Two principal methods have been used to functionalize polystyrene for phase transfer catalysts, chloromethylation of pre-formed beads and copolymerization of chloromethylstyrene monomer with styrene and divinylbenzene. The chloromethylation route employs chloromethyl methyl ether (a cancer suspect agent), and a Lewis acid, usually stannic chloride.Substitution proceeds >90% para and is accompanied by some intrapolymer alkylation, which puts additional cross-links into the polymer... 

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