A practical route for the preparation of poly(4-hydroxystyrene), a useful photoresist material
TL;DR: In this article, the synthesis and characterization of poly(4-hydroxystyrene) and poly (4-vinylphenol) by the polymer modification route are reported. And the polymers were characterized via gel permeation chromatography, IR, UV, 1 H NMR, and 13 C NMR spectroscopic techniques.
Abstract: The synthesis and characterization of poly(4-hydroxystyrene) (PHS) and poly(4-vinylphenol) (PVPh) by the polymer modification route are reported. Polystyrene prepared by free-radical and anionic polymerization was acetylated quantitatively to poly(4-acetylstyrene) (ACPS) with acetyl chloride and anhydrous aluminum trichloride in carbon disulfide. The acetylation worked equally well in a mixture of 1,2-dichloroethane (DCE) and nitrobenzene containing largely DCE. The extent of the acetylation was estimated by 1 H NMR. The oxidation of ACPS was carried out with various oxidizing agents and reaction conditions. The peracetic acid oxidation in chloroform resulted in quantitative oxidation to poly(4-acetoxystyrene) (APS) as estimated by 1 H NMR spectroscopy. The treatment of APS with hydrazine hydrate in dioxane resulted in the formation of PVPh. Deacetylation occurred with equal versatility in a mixture of aqueous sodium hydroxide and tetrahydrofuran. All the polymers were characterized via gel permeation chromatography, IR, UV, 1 H NMR, and 13 C NMR spectroscopic techniques. This is the first report on the synthesis of ACPS, APS, and PHS of reasonably narrow molecular weight distributions or otherwise by the polymer modification route.
Citations
More filters
TL;DR: In this paper, the authors report the synthesis of homo, block, and statistical copolymers with controlled molecular weights, compositions, and relatively narrow polydispersities via atom transfer radical polymerization.
Abstract: The incorporation of metal–ligand interactions into macromolecules imparts to them unique and potentially useful properties. We report the synthesis of homo, block, and statistical copolymers with controlled molecular weights, compositions, and relatively narrow polydispersities via atom transfer radical polymerization that contain activated esters for the subsequent incorporation of terpyridine. This approach is universal and allows facile access to macromolecules with rich chemical functions, illustrated here with metal ligands. Comonomers include methyl, n-butyl, and poly(ethylene glycol) methyl ether methacrylate as well as styrene. The addition of lanthanide ions to the final copolymers generates emissive materials with blue, green, red, or purple light, depending on the metal used. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5831–5843, 2005
79 citations
TL;DR: The results demonstrate that these self-assembled NTBH vesicles have great scope in the field of medicine as they symbolize themselves as promising carriers for the stimuli-triggered intracellular delivery of hydrophobic drugs.
Abstract: Synthesis of a new molecular architecture, an amphiphilic, norbornene-derived thiobarbiturate homopolymer (NTBH), by ring-opening metathesis polymerization (ROMP) and its characterization is discussed. The newly designed hompolymer shows a self-assembled vesicle formation in aqueous solution. Dynamic light scattering and critical aggregation concentration studies confirm the aggregate formation in solution while atomic force microscopy and transmission electron microscopy of the dried sample on the silicon substrate further confirm the vesicular morphologies of these amphiphilic homopolymers. Encapsulation studies of hydrophilic doxorubicin and hydrophobic Nile red suggest the reversible nature of the NTBH vesicles. Dye release studies in acidic and lipophilic environment demonstrate the stimuli-responsive nature of the novel systems. The results demonstrate that these self-assembled NTBH vesicles have great scope in the field of medicine as they symbolize themselves as promising carriers for the stimuli-...
50 citations
TL;DR: In this paper, a modified syndiotactic polystyrene containing COCH 2 CH 2 COOH fragments in side phenyl rings was characterized by FTIR and 1 H NMR spectroscopy, and the effects of reaction conditions on the degree of succinoylation of s-sPS were investigated.
Abstract: Syndiotactic polystyrene has been chemically modified with succinic anhydride by use of Friedel–Crafts acylation reaction in the presence of anhydrous aluminum chloride in carbon disulfide. The modified syndiotactic polystyrene containing –COCH 2 CH 2 COOH fragments in side phenyl rings, named succinoylated syndiotactic polystyrene (s-sPS), was characterized by FTIR and 1 H NMR spectroscopy. The effects of reaction conditions on the degree of succinoylation of s-sPS were investigated. In addition, the effects of incorporation of carboxyl groups into syndiotactic polystyrene on the thermal behavior were studied by differential scanning calorimetry in comparison with pure syndiotactic polystyrene. It was found that the crystallization temperature, melting temperature, and degree of crystallinity of the modified polymer decreased with increasing the degree of succinoylation, while the glass transition temperature increased.
30 citations
TL;DR: Modulation of the degree of crosslinking in the hydrogels resulted in a defined variation of the rheological behavior in terms of elasticity and mesh size of the corresponding materials, addressing the demand of sustainable strategies for defunctionalization of renewable feedstocks.
Abstract: Carrier-free enzyme immobilization techniques are an important development in the field of efficient and streamlined continuous synthetic processes using microreactors. Here, the use of monolithic, self-assembling all-enzyme hydrogels is expanded to phenolic acid decarboxylases. This provides access to the continuous flow production of p-hydroxystyrene from p-coumaric acid for more than 10 h with conversions ≥98% and space time yields of 57.7 g·(d·L)−1. Furthermore, modulation of the degree of crosslinking in the hydrogels resulted in a defined variation of the rheological behavior in terms of elasticity and mesh size of the corresponding materials. This work is addressing the demand of sustainable strategies for defunctionalization of renewable feedstocks.
24 citations
TL;DR: In this paper, a heterogeneous atom transfer radical polymerization (ATRP) was used to synthesize a graft copolymer using 2-bromo-2-methylpropanoyl bromide modified syndiotactic polystyrene (BMPsPS) as macroinitiator and copperbromide combined with 2,2′-bipyridine as catalyst in anisole at room temperature.
Abstract: Syndiotactic polystyrene- graft -poly(glycidyl methacrylate) (sPS- graft -PGMA) copolymer was synthesized by a heterogenous atom transfer radical polymerization (ATRP) using 2-bromo-2-methylpropanoyl bromide modified syndiotactic polystyrene (BMPsPS) as macroinitiator and copper bromide combined with 2,2′-bipyridine as catalyst in anisole at room temperature. The macroinitiator with 7.0 mol% bromine content was prepared from Friedel–Crafts acylation reaction of sPS with 2-bromo-2-methylpropanoyl bromide in a heterogeneous process. It was found that BMsPS macroinitiator was well swelled in the mixture of anisole and GMA, the equilibrium swelling degree could reach 370%. The resultant polymer was characterized by FTIR and NMR spectroscopies. In addition, the thermal properties of the graft copolymers were also investigated with differential scanning calorimetry (DSC).
23 citations
References
More filters
217 citations
TL;DR: In this paper, an efficient synthetic route to pure, high molecular weight poly(p-hydroxystyrene) is reported, which involves synthesis of a new monomer, p-tert-butoxycarbonyloxystyrene, polymerization by radical initiation or by cationic initiation in liquid SO2, followed by thermolysis or acidolysis of the tertbutoxy carbonyl protecting group.
Abstract: An efficient synthetic route to pure, high molecular weight poly(p-hydroxystyrene) is reported. The route involves synthesis of a new monomer, p-tert-butoxycarbonyloxystyrene, polymerization by radical initiation or by cationic initiation in liquid SO2, followed by thermolysis or acidolysis of the tert-butoxycarbonyl protecting group. Porous, crosslinked resin beads containing the nucleophilic, phenol pendant group have been prepared in a similar fashion from the precursor terpolymer of p-tert-butoxycarbonyloxystyrene, styrene and divinylbenzene. The utility of this resin for solid-phase synthesis has been demonstrated.
190 citations
123 citations
TL;DR: A new biocidal polymer, poly(1,3-dichloro-5-methyl-5-(4'-vinylphenyl)-hydantoin), is described in this paper.
Abstract: A new biocidal polymer is described. The compound, poly(1,3-dichloro-5-methyl-5-(4'-vinylphenyl)-hydantoin), is prepared in a three-step synthesis from commercial polystyrene. It is insoluble in water and common organic solvents and acts as a contact biocide for contanainated water or air flowed through it. It does not leach organic impurities or levels of free chlorine greater than 1 part per million into flowing water and, thus, may represent a innovation in disinfection technology
112 citations
84 citations