Controlled radical polymerization of vinyl acetate in presence of mesoporous silica supported TiCl4 heterogeneous catalyst

Abstract

The heterogeneous TiCl 4 catalysts supported on mesoporous mobile composition of matter (MCM-41) and mesoporous silicone particles synthesized from block copolymer of PPG-PEG-PPG (SPB) complexed with dimethyl formamide (DMF) ligand were used in a controlled free radical reaction with benzoyl peroxide (BPO) initiator in bulk polymerization of vinyl acetate (VAc). In this polymerization process, mesoporous particle of SPB increased the reactivity of TiCl 4 catalyst with DMF ligand. The active site formed on the surface and the pores of the catalyst produced specific sequences of VAc on the chain with different thermal and microstructural properties and crystallinity.

Beyond a solvent: triple roles of dimethylformamide in organic chemistry

“…This uniquely versatile and powerful chemical is frequently used as a solvent for preparation of colloids, 4-6 synthesis of block-copolymers, 7,8 and also many other types of organic reactions 9 like solvent-free hydrolysis, allylation, decarboxylation, polymerization, etc. [10][11][12][13][14][15] It is also found as a perfect solvent for peptide coupling in the pharmaceuticals industry, in development and production of pesticides and in the manufacture of adhesives, synthetic leathers, bers, lms, and surface coatings. It also is used in the manufacturing of dyes as an important raw material which is consumed during a reaction.…”

Highly effective organometallic‐mediated radical polymerization of vinyl acetate using alumina‐supported Co(acac)2 catalyst: A case study of adsorption and polymerization

“…But, in the thermogram of PVA synthesized by [alumina‐Co(acac) 2 ], in addition to this T g , another T g is seen at about 123 °C. The presence of two different T g temperatures in thermogram indicates two different sequences of PVAc formed from two different sites of the [alumina‐Co(acac) 2 ] catalysts in polymerization reaction . Moreover, the thermogram of PVAc prepared in the presence of alumina support exhibited two endothermic peaks at ∼76 (broad peak and high integration) and 158 °C (low intensity).…”

“…The structure of the obtained PVAc from supported‐CMRP with [alumina‐Co(acac) 2 ] catalysts at 12.27% conversion (in reaction condition 3) was analyzed by 1 H‐NMR spectroscopy. Typical signals of PVAc identified are presented in Figure …”

Silicone Macroinitiator in the Atom Transfer Radical Polymerization of Styrene and Vinyl Acetate: Synthesis and Characterization of Novel Thermoreversible Block Copolymers

“…This block copolymer revealed a thermosensitive micelle formation behavior in the solid state (12)(13)(14)(15)(16)(17). As temperature increased, the polyrotaxane based block copolymer chains were dehydrated while the color of complex was changed from white to green through hydrophobic-hydrophobic interactions (4,18). The complex is colorless; however the presence of catalyst, like CuCl-ligand turns the block copolymer green.…”