Radical Polymerization Of Vinyl Chloride Research Articles

Role of Cyclic Ketene Dithioacetals in Free Radical Polymerization of Vinyl Chloride

AbstractThe role of the sulfur analog of cyclic ketene acetals in the synthesis of polyvinyl chloride is examined in this study. In this context, whether 2‐methylene‐1,3‐dithiolane (S‐CKA5), 2‐methylene‐1,3‐dithione (S‐CKA6), and 2‐methylene‐1,3‐dithiepane (S‐CKA7) monomers are involved in the radical polymerization of vinyl chloride through the ring opening reaction is examined by quantum chemical methods. In light of calculations at the M06‐2X/6‐31+G(d) level, it is concluded that, in general, S‐CKAs undergo little or no ring‐opening and form block copolymers, mainly with the homopolymerization of S‐CKAs and their ring‐retaining step. It is determined that S‐CKA7 is the most prone to ring‐opening reaction and inserting dithioate links to the polymer backbone. However, the radical ring‐opening of S‐CKA7 is strongly reversible, as in other S‐CKAs.

Under pressure: electrochemically-mediated atom transfer radical polymerization of vinyl chloride

Electrochemically mediated ATRP (eATRP) of vinyl chloride (VC), a less activated monomer, was successfully achieved. It is the first report on eATRP of a gaseous monomer under pressure.

Polymerization of Vinyl Chloride at Ambient Temperature Using Macromolecular Design via the Interchange of Xanthate: Kinetic and Computational Studies

Reversible deactivation radical polymerization of vinyl chloride (VC) by methyl (ethoxycarbonothioyl)sulfanyl acetate (MEA)-mediated macromolecular design via the interchange of xanthate (MADIX) po...

Controlled Radical Polymerization of Vinyl Chloride Mediated by Xanthene-9-Thione

The controlled radical polymerization (CRP) of vinyl chloride monomer (VCM), a low activity monomer with high radical reactivity, is still a true challenge. In this study, a novel CRP of VCM with high monomer conversion at 45 °C with xanthene-9-thione (XT) as mediator and bis(4-tert-butylcyclohexyl)peroxydicarbonate (TBCP) as initiator is achieved. The Mn of the produced poly(vinyl chloride) (PVC) increases slightly with increasing monomer conversion and could be mediated in the range from 6k to 12k by simply changing the molar ratio of TBCP/XT while the dispersity maintains around 2.0. The fidelity of XT dormant groups of PVC-XT is about 60–80% and depends on the ratio of TBCP/XT. With the as-prepared PVC-XT as macroinitiator, block copolymerizations of methyl methacrylate (MMA), n-butyl acrylate (BA), and styrene (St) are carried out and the PVC-b-PMMA, PVC-b-PBA, and PVC-b-PSt block copolymers have been synthesized successfully.

Synthesis of block copolymers from polyvinyl chloride prepared in the presence of nitroxyl radicals of the imidazoline series

Specific features of radical polymerization of vinyl chloride in the presence of nitroxyl radicals of the imidazoline series (2-methyl-2,3-diphenyl-1,4-diazaspiro[4,5]dec-3-ene-1-oxyl, 2,2,5,5-tetramethyl-4-phenyl-2,5-dihydroimidazole-1-oxyl, 2,2,5-trimethyl-4,5-diphenyl-2,5-dihydroimidazole-1-oxyl) were studied. The possibility of preparing vinyl chloride-styrene block copolymers in the presence of these nitroxyl radicals was demonstrated, suggesting the occurrence of the polymerization by the reversible inhibition mechanism. The molecular-mass characteristics and the glass transition points of the synthesized samples were determined.

A Density Functional Theory Study of Poly (vinyl chloride) (PVC) Free Radical Polymerization

AbstractSummary: Quantum chemistry was applied to the free radical polymerization of Vinyl Chloride with the aim of elucidating the reaction kinetics and especially the formation of structural defects and low molecular weight polymer. The radical reactions were studied using the Density Functional Theory. All calculations were performed with B3LYP functionals and in particular the 6‐31G(d,p) basis set was selected to evaluate the exchange and correlation energies. The computational method was first validated by predicting the rate constant of the propagation step and comparing the calculated values to experimental ones. Then intramolecular chain transfer, β‐scission and branching reactions were also investigated, due to their direct connection with the production of defects in the growing chains. A comparison of the evaluated kinetic constants of such secondary reactions with other computational evaluations and experimental data was finally made.

Processability and characterization of poly(vinyl chloride)‐b‐poly(n‐butyl acrylate)‐b‐poly(vinyl chloride) prepared by living radical polymerization of vinyl chloride. Comparison with a flexible commercial resin formulation prepared with PVC and dioctyl phthalate

AbstractThis work reports the synthesis and processing of a new flexible material based on PVC produced by living radical polymerization. The synthesis was carried out in a two‐step process. In the first step the macroinitiator α, ω‐di(iodo)poly(butyl acrylate) [α, ω‐di(iodo)PBA] was synthesized in water by single electron transfer/degenerative chain transfer mediated living radical polymerization (SET‐DTLRP) catalyzed by Na2S2O4. In the second step this macroinitiator was reinitiated by SET‐DTLRP of vinyl chloride (VC), thereby leading to the formation of the block copolymer poly(vinyl chloride)‐b‐poly(butyl acrylate)‐b‐poly(vinyl chloride) [PVC‐b‐PBA‐b‐PVC]. This new material was processed on a laboratory scale. The DMTA traces showed only a single glass transition temperature, thus indicating that no phase segregation was present. The copolymers were studied with regard to their processing, miscibility, and mechanical properties. The first comparison with commercial formulations made with PVC and dioctyl phthalate (DOP) is presented. J. VINYL ADDIT. TECHNOL., 12:156–165, 2006. © 2006 Society of Plastics Engineers

Synthesis of poly(vinyl chloride)‐b‐poly(2‐ethylhexyl acrylate)‐b‐poly(vinyl chloride) by the competitive single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride initiated from α,ω‐di(iodo)poly(2‐ethylhexyl acrylate) and catalyzed with sodium dithionite in water

Abstractα,ω‐Di(iodo)poly(2‐ethylhexyl acrylate)s [α,ω‐di(iodo)P2EHAs] with number‐average molecular weights of 13,700 and 20,400 were synthesized by the single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization (SET–DTLRP) of 2‐ethylhexyl acrylate initiated with iodoform and catalyzed by sodium dithionite in water at 23 and 30 °C. These α,ω‐di(iodo)P2EHAs were used as macroinitiators for the SET–DTLRP of vinyl chloride, which was carried out under similar reaction conditions to synthesize ABA block copolymers containing poly(vinyl chloride) in the A blocks and poly(2‐ethylhexyl acrylate) in the B block. Poly(vinyl chloride)‐b‐poly(2‐ethylhexyl acrylate)‐b‐poly(vinyl chloride) was synthesized with 100% initiator efficiency. This synthetic method provides for the first time access to a diversity of block copolymers and other complex architectures based on combinations of thermoplastic poly(vinyl chloride)and elastomeric polyacrylates. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2276–2280, 2005

Ultrafast synthesis of poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) block copolymers by the Cu(0)/tris(2‐dimethylaminoethyl)amine‐catalyzed living radical block copolymerization of methyl methacrylate initiated with α,ω‐di(iodo)poly(vinyl chloride) in the presence of dimethyl sulfoxide at 25 °C

Abstractα,ω‐Di(iodo)poly(vinyl chloride)s, with number‐average molecular weights ranging from 2100 to 29,500 and molecular weight distributions (weight‐average molecular weight/number‐average molecular weight) ranging from 1.74 to 2.16, were prepared by the previously reported single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride initiated with iodoform and catalyzed by sodium dithionite in water at 25–35 °C. These α,ω‐di(iodo)poly(vinyl chloride) macroinitiators were used for the synthesis of poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) (PMMA‐b‐PVC‐b‐PMMA) block copolymers via the metal‐catalyzed living radical block copolymerization of methyl methacrylate. In this article, we report the effects of various ligands on the rate of block copolymerization mediated by Cu(0) in dimethyl sulfoxide (DMSO). The block copolymerization catalyzed by Cu(0)/tris(2‐dimethylaminoethyl)amine in DMSO at 90 °C yielded block copolymers in less than 15 min, whereas at 25 °C, the reaction times ranged from 60 to 100 min. Therefore, this ultrafast synthetic method provided access to PMMA‐b‐PVC‐b‐PMMA, regardless of the reaction temperature, in the same range of reaction times as the induction period of the same reactions carried out at 90 °C in diphenyl ether and catalyzed by CuCl/2,2′‐bipyridine. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1660–1669, 2005

Synthesis of poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) block copolymers by CuCl/2,2′‐bipyridine‐catalyzed living radical block copolymerization initiated from α,ω‐di(iodo)poly(vinyl chloride) prepared by single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization

Abstractα,ω‐Di(iodo)poly(vinyl chloride)s with number‐average molecular weights (Mn's) of 2100–29,800 and weight‐average molecular weight/number‐average molecular weight (Mw/Mn) ratios of 1.66–2.16 were synthesized by the single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride initiated with CHI3 and catalyzed by Na2S2O4. These α,ω‐di(iodo)poly(vinyl chloride)s were used as initiators for the metal‐catalyzed living radical block copolymerization of methyl methacrylate mediated by CuCl/2,2′‐bipyridine. Poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) block copolymers with Mn values of 36,500–95,700 and Mw/Mn values lower than 1.20 were synthesized by this novel and general synthetic method. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1478–1486, 2005

Functionalization of the active chain ends of poly(vinyl chloride) obtained by single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization: Synthesis of telechelic α,ω‐di(hydroxy)poly(vinyl chloride)

AbstractThe chloroiodomethyl chain ends of poly(vinyl chloride) (PVC) obtained by the single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride initiated with iodoform were quantitatively functionalized by the reaction with 2‐allyloxyethanol (CH2CHCH2OCH2CH2OH). This reaction was performed in dimethyl sulfoxide at 70 °C and was catalyzed by sodium dithionite/sodium bicarbonate. The resulting product is the first example of telechelic PVC [α,ω‐di(hydroxy)PVC]. A possible mechanism for this reaction was suggested. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1255–1260, 2005

Accelerated synthesis of poly(methyl methacrylate)-b-poly(vinyl chloride)-b-poly(methyl methacrylate) block copolymers by the CuCl/tris(2-dimethylaminoethyl)amine-catalyzed living radical block copolymerization of methyl methacrylate initiated with ?,?-di(iodo)poly(vinyl chloride) in dimethyl sulfoxide at 90 �C

α,ω-Di(iodo)poly(vinyl chloride)s [α,ω-di(iodo)PVCs] with number-average molecular weights ranging from 2100 to 20,000 and weight-average molecular weight/number-average molecular weight ratios ranging from 1.72 to 2.16 were synthesized through the single-electron-transfer/degenerative-chain-transfer mediated living radical polymerization of vinyl chloride initiated with iodoform and catalyzed by sodium dithionite in water at 25–35 °C. These α,ω-di(iodo)PVCs were used as macroinitiators for the metal-catalyzed living radical block copolymerization of methyl methacrylate to produce poly(methyl methacrylate)-b-poly(vinyl chloride)-b-poly(methyl methacrylate) block copolymers. By searching various copper derivatives, ligands, and solvents, it has been found that CuCl/tris(2-dimethylaminoethyl)amine in dimethyl sulfoxide at 90 °C provides an accelerated method for the synthesis of block copolymers. Poly(methyl methacrylate)-b-poly(vinyl chloride)-b-poly(methyl methacrylate) block copolymers with number-average molecular weights of 41,000–106,700 were produced by this method in 30–80 min. These reaction times were within the range of induction times exhibited when the same block copolymers were synthesized with CuCl/2,2′-bipyridine in diphenyl ether at 90 °C. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1649–1659, 2005

Single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride catalyzed by thiourea dioxide/octyl viologen in water/tetrahydrofuran at 25 °C

AbstractThe single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization (SET–DTLRP) of vinyl chloride (VC) in H2O/tetrahydrofuran at 25 °C catalyzed by thiourea dioxide [(NH2)2CSO2] is reported. This polymerization occurs only in the presence of a basic sodium bicarbonate (NaHCO3) buffer and the electron‐transfer cocatalyst octyl viologen. The resulting poly(vinyl chloride) (PVC) has a number‐average molecular weight of 1500–7000 and a weight‐average molecular weight/number‐average molecular weight ratio of 1.5. This PVC does not contain detectable amounts of structural defects and has both active chloroiodomethyl and inactive chloromethyl chain ends. Because of possible side reactions caused by the primary sulfoxylate anion (SO), the catalytic activity of (NH2)2CSO2 in the SET–DTLRP of VC is lower than that of the single‐electron‐transfer agent sodium dithionite. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 287–295, 2005

Non‐transition metal‐catalyzed living radical polymerization of vinyl chloride initiated with iodoform in water at 25 °C

AbstractNon‐transition metal‐catalyzed living radical polymerization (LRP) of vinyl chloride (VC) in water at 25–35 °C is reported. This polymerization is initiated with iodoform and catalyzed by Na2S2O4. In water, S2Odissociates into SOthat mediates the initiation and reactivation steps via a single electron transfer (SET) mechanism. The exchange between dormant and active propagating species also includes the degenerative chain transfer to dormant species (DT). In addition, the SO2released from SOduring the SET process can add reversibly to poly(vinyl chloride) (PVC) radicals and provide additional transient dormant ∼SOradicals. This novel LRP proceeds mostly by a combination of competitive SET and DT mechanisms and, therefore, it is called SET‐DTLRP. Telechelic PVC with a number‐average molecular weight (Mn) = 2,000–55,000, containing two active ∼CH2CHClI chain ends and a higher syndiotacticity than the commercial PVC were obtained by SET‐DTLRP. This PVC is free of structural defects and exhibits a higher thermal stability than commercial PVC. SET‐DTLRP of VC is carried out under reaction conditions related to those used for its commercial free‐radical polymerization. Consequently, SET‐DTLRP is of technological interest both as an alternative commercial method for the production of PVC with superior properties as well as for the synthesis of new PVC‐based architectures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6267–6282, 2004

Novel copolymers via nitroxide mediated controlled free radical polymerization of vinyl chloride

AbstractControlled free radical polymerization (CFRP) of vinyl chloride (VCM) and copolymerization with several comonomers have been studied in aqueous suspension. Therefore di‐tert‐butylnitroxide and three novel nitroxyl radicals were used as mediating agents. Copolymerization of VCM with styrene, partly combined with acrylonitrile, maleic acid anhydride and maleic acid imide as well as methyl methacrylate, n‐butyl methacrylate, butyl acrylate and butadiene have been achieved, demonstrating an efficient route for novel vinyl chloride copolymer architecture.

Living radical polymerization of vinyl chloride initiated with iodoform and catalyzed by nascent Cu0/tris(2‐aminoethyl)amine or polyethyleneimine in water at 25 °C proceeds by a new competing pathways mechanism

AbstractThe first example of living radical polymerization of vinyl chloride carried out in water at 25 °C is reported. This polymerization was initiated by iodoform and catalyzed by nascent Cu0 produced by the disproportionation of CuI in the presence of strongly CuII binding ligands such as tris(2‐aminoethyl)amine or polyethyleneimine. The resulting poly(vinyl chloride) was free of structural defects, had controlled molecular weight and narrow molecular weight distribution, contained two ∼CHClI active chain ends, and had a higher syndiotacticity (62%) than the one obtained by conventional free‐radical polymerization at the same temperature (56%). This novel polymerization proceeds, most probably, by a combination of competitive pathways that involves activation by single electron transfer mediated by nascent Cu0 and degenerative chain transfer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3283–3299, 2003

Metal-catalyzed living radical graft copolymerization of butyl methacrylate and styrene initiated from the structural Defects of narrow molecular weight distribution poly(vinyl chloride)

Poly(vinyl chloride) (PVC) prepared by the radical polymerization of vinyl chloride (VC) contains allyl chloride and tertiary chloride structural defects. The graft copolymerization initiated from the structural defects of PVC should eliminate the structural defects of PVC and, therefore, should provide novel graft copolymers that will exhibit both new physical properties and higher thermal stability than the parent PVC. The preliminary graft copolymerization experiments reported previously from our laboratory were performed with PVC with broad molecular weight distribution and did not allow kinetic experiments to be performed. Model compounds for the allyl chloride defects in PVC were used as initiators and gave almost quantitative initiation in the case of styrene (0.99), while for methacrylates the maximum initiator efficiency was only 0.40. Based on these data, the successful grafting of PVC with butyl methacrylate (BMA) and the less successful grafting of PVC with styrene were difficult to be explained. This publication reports the metal catalyzed living radical graft copolymerization experiments initiated from the structural defects of PVC with narrow molecular weight distribution. These experiments demonstrate that, contrary to the results obtained using model compounds as initiators, the structural defects of PVC provide an excellent initiation efficiency for the graft copolymerization of BMA and a less efficient initiation for the case of styrene. Under suitable reaction conditions, the initiation efficiency from the structural defects of PVC for the graft copolymer- ization of BMA can be considered to be quantitative.

Aqueous room temperature metal-catalyzed living radical polymerization of vinyl chloride.

This paper describes the room-temperature living radical polymerization (LRP) of vinyl chloride in H2O/THF in the presence of Cu0 or CuI salts as catalysts, tren or PEI as ligands, and iodoform as initiator. The disproportionation reaction 2CuI + L --> Cu0 + CuII(L) is the crucial step, as it continuously provides the active species for both the initiation (Cu0) and the reversible termination step (CuII). Mn was found to increase linearly with conversion and is in good agreement with Mth, with the Mw/Mn being approximately 1.5.

Copolymerization of 1-(Vinyloxyalkoxy)-2,3-epoxypropanes with Vinyl Chloride

Binary radical polymerization of vinyl chloride with 1-(vinyloxyalkoxy)-2,3-epoxypropanes in acetone and dimethyl sulfoxide was studied. The copolymerization constants and the microstructural parameters of the resulting copolymers were calculated.

From metal‐catalyzed radical telomerization to metal‐catalyzed radical polymerization of vinyl chloride: Toward living radical polymerization of vinyl chloride

AbstractThe metal‐catalyzed radical polymerization of vinyl chloride (VC) in ortho‐dichlorobenzene initiated with various activated halides, such as α,α‐dihaloalkanes, α,α,α‐trihaloalkanes, perfloroalkyl halides, benzyl halides, pseudohalides, allyl halides, sulfonyl halides, α‐haloesters, α‐halonitriles, and imidyl halides, in the presence of Cu(0)/2,2′‐bipyridine, Fe(0)/o‐phenantroline, TiCp2Cl2, and other metal catalysts is reported. The formation of the monoadduct between the initiator and VC was achieved with all catalysts. However, propagation was observed only for metals in their zero oxidation state because they were able to reinitiate from geminal dihalo or allylic chloride structures. Poly(vinyl chloride) with molecular weights larger then the theoretical limit allowed by chain transfer to VC were obtained even at 130 °C. In addition, the most elemental features of a living radical polymerization, such as a linear dependence of the molecular weight and a decrease of polydispersity with conversion, were observed for the most promising systems based on iodine‐containing initiators and Cu(0), that is, ICH2PhCH2I/Cu(0)/bpy (where bpy = 2,2′‐bipyridyl), at 130 °C. However, because of the formation of inactive species via chain transfer to VC and other side reactions, the observed conversions were in most cases lower than 40%. A mechanistic interpretation of the chain transfer to monomer in the presence of Cu species is proposed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3392–3418, 2001