Provided is a method for the polymerization of vinyl ethers catalyzed by complexes of a lithium salt and a polyether. The compositions are cured by the use of an effective amount of a free radical photoinitiator. Free radical copolymerization of vinyl ethers is also possible. The synthesis of different vinyl ether esters reached high conversions above 90 % after less than. These polymerization techniques generate many important commodity polymers where their broad range of molecular weight distribution gives rise to important physical properties. Isobutylene only can undergo cationic polymer ization. Synthesis and free radical polymerization of vinyl ethers. Catalystcontrolled stereoselective cationic polymerization. Today free radical polymerization accounts for a large portion of massproduced polymers. Vinyl ethervinyl ester copolymerization by cationic and.
A series of emulsion polymerizations of various hydrophobic monomers such as vinyl acetate vac, methyl methacrylate mma, ethyl acrylate ea, and styrene st were performed using poly2hydroxyethyl vinyl ether pheve with hydrophilic azoinitiator, 2,2. Photoinitiated radical polymerization of vinyl ethermaleate. Free radical curing uv photoinitiator absorbs uv light and generates free radicals free radicals react with double bonds causing chain reaction and polymerization cationic curing uv photoinitiator absorbs uv light and generates a lewis acid acid reacts with epoxy groups resulting in polymerization. The vinyl ether monomers may be defined by the formula rch croz nb.
Steric effect in the free radical polymerization of vinyl. The study of the polymerization and copolymerization of vinyl ethers containing cyclohexyl, decahydro. The photochemically generated radicals were then oxidized by diphenyliodonium ions to the corresponding cations. Characteristics and mechanism of vinyl ether cationic. The photoinitiated radical polymerization of difunctional vinyl ether maleate mixtures has been studied by realtime i. Living cationic polymerization is a living polymerization technique involving cationic propagating species. Poly isobutyl vinyl ethers with mn up to 8600 g mol. Other articles where emulsion polymerization is discussed.
Depending on the type of polymerization, 1 could be a living free radical, an electrophiliccationic moiety,oracarbanion. Request pdf vinyl ethervinyl ester copolymerization by cationic and radical interconvertible simultaneous polymerization in this. Vinyl chloride only can undergo radical polymerization. Free radical polymerization frp is a method of polymerization by which a polymer forms by the successive addition of free radical building blocks. Cationic polymerization of poly vinyl ether bearing a tempo radical. Effects of water and comonomers on the free radical polymerization using 2hydroxyethyl vinyl ether heve were investigated in detail. Living cationic polymerization of tertbutyl vinyl ether tbve was achieved by the 1isobutoxyethyl acetate 1et1.
Living cationic polymerizations, examples of cationic polymerization, isobutyl rubber synthesis, polyvinyl ethers cationic polymerization some differences between cationic and anionic polymerization rates are faster for cationic 1 or more orders of. In the period 191050, many contributed to the develop ment of freeradical polymerization. Living cationic polymerizations, examples of cationic polymerization, isobutyl rubber synthesis, polyvinyl ethers cationic polymerization some differences between cationic and anionic polymerization rates are faster for cationic 1 or more orders of magnitude faster than anionic or free radical. Vinyl ether monomers and polymers wiley online library. Monomers that are not susceptible to free radical addition a. A new photoinitiating system for living cationic polymerization of vinyl ethers is reported.
Aqueous cationic polymerizations of vinyl ethers isobutyl vinyl ether ibve, 2chloroethyl vinyl ether ceve, and nbutyl vinyl ether nbve were performed for the first time by a cumohbc6f53et2o initiating system in an air atmosphere. Ptve was synthesized as a new active material for organic radical batteries. Bpo or aibn to yield a pair of free radicals r, and the second the addition of a monomer to the primary radical r to yield the chain radical, which is called the initiation. Shinji sugihara, masaru kitagawa, yuichi inagawa, izabela magdalena zaleska and isao ikeda, effects of monomer and ether structure on metalfree living cationic polymerization of various vinyl ethers using hydrogen chloride with ether, polymer bulletin, 64, 3, 209, 2010. The radical polymerizations of divinyl ether dve, cispropenyl vinyl ether pve and 2methylpropenyl vinyl ether ch3pve were carried out with aibn initiator. Controlled radical polymerization guide sigmaaldrich. However, the polymerization under free radical conditions gives only lowmolecularweight oligomers and only copolymers can be synthesized. Free radicals can be formed by a number of different mechanisms, usually involving separate initiator molecules.
Oct 04, 1994 preferably, the vinyl ether monomers comprise up to about 35 equivalent % of the formulation particularly about 0. Well over 100 billion pounds of polymer are produced each year, and it is expected that this. Cationic polymerization of polyvinyl ether bearing a. The most important mechanism for the decay of propagat ing species in radical polymerization is radical radical reaction by. Modern use of vinyl ethers and vinyl amids in uv curable.
Photoinitiated radical polymerization of vinyl ether. Understanding vinyl acetate polymerisation accidents. Furthermore, pvac would be a branch polymer in the chaintransfer reaction. Photopolymerization and physical properties of thiolvinyl. Free radical copolymerization of acrylates and vinyl ethers. Ionic and freeradical polymerization and copolymerization of vinyl. Nitroxidemediated free radical polymerization rheokinetics of free radical polymerization. Introduction to the basics of uveb chemistry and formulations. Explaining free radical addition in the polymerisation of ethene. As in free radical polymerization, there are initiation and propagation. In order to overcome the challenge of direct radical polymerization of vinyl ethers, commercial hydroxyfunctional vinyl ethers such as 2hydroxyethyl vinyl ether heve were subjected to free radical polymerization, generating.
Polymers 7ab and 9ab were not soluble in common organic solvents such as acetone and dmso due to crosslinking. The molecular weights of the obtained polymers can be controlled with the feed ratio of the. Figure 2 gives an overview of chemistries of methocel cellulose ethers within the matrix of substitution and nomenclature. Living cationic polymerization of tert butyl vinyl ether by. Free radical promoted cationic polymerization is an elegant method to initiate cationic polymerization by the use of free radical initiators. Copolymerization of butyl vinyl ether and methyl methacrylate. Instead of synthesizing polystyrene, you will prepare a copolymer, an addition polymer which contains two different monomer units that are present in either a random or alternating arrangement, using styrene and maleic anhydride. Bifunctional monomers containing both electron rich alkyl. Polymerization rate in figure 5 the conversion of acrylate 1407 cm1 and vinyl ether groups 1618 cm1 are plotted as a function of vinyl ether content. Cationic polymerization free online course materials. Free radical polymerization frp is a type of chain growth polymerization, along with anionic, cationic and coordination polymerization. Freeradical copolymerization of vinyl ethers is also possible. Electrochemically controlled cationic polymerization of vinyl ethers.
Chemical initiation the decomposition of the initiator e. The resulting polymers are produced under mild and controlled conditions and are useful in adhesives and coatings as well as in other uses such as for polymer electrolytes in batteries and for viscosity. To emphasize the importance of stabilization of the charged reactive center on the growing chain. Free radical polymerization is one of the processes of polymer formation. A study was made of the polymerization of some vinyl ethers of ethanolamines in presence of ionogenic and freeradical catalysts. Styrene can undergo radical, anionic, cationic, and coordination polymerization. Mechanistic insight into the photocontrolled cationic. The radical produced by attack of a thiyl radical on the terminal methylene of the vinyl ether is stabilised by the oxygen atom of the ether group and therefore it is not surprising to find that vinyl ethers are very reactive ene components of the thiolene reaction 4 the ether substituent on the double bond reduces the ionisation potential of. This invention concerns a living free radical polymerization process for preparing polymers having a narrow distribution of molecular weights.
Poly vinyl chloride produced in bulk polymerization using monomer soluble free radical initiators. Polyvinyl acetate produced industrially by the polymerization of vinyl acetate in bulk or solution processes. Poly vinyl acetate produced industrially by the polymerization of vinyl acetate in bulk or solution processes. Living cationic polymerization of vinyl ethers through a. Most of the homopolymers and copolymers of vinyl chloride, however, are produced by suspension polymerization. Freeradical polymerization frp is a method of polymerization by which a polymer forms by the successive addition of freeradical building blocks. The polymerization proceeded in a reproducible manner through the careful design of experimental conditions adding initiator, cosolvents, and. Shinji sugihara, masaru kitagawa, yuichi inagawa, izabela magdalena zaleska and isao ikeda, effects of monomer and ether structure on metal free living cationic polymerization of various vinyl ethers using hydrogen chloride with ether, polymer bulletin, 64, 3, 209, 2010. Methocel cellulose ethers as suspending agents for. One of the most widely used methods of manufacturing vinyl polymers, emulsion polymerization involves formation of a stable emulsion often referred to as a latex of monomer in water using a soap or detergent as the emulsifying agent. Vinyl ethers undergo homopolymerization via a cationic mechanism.
A preferred complex is a complex of lithium tetrafluoroborate and a glyme. Unprecedented controlled radical vinyl polymerization crp of vinyl ethers using reversible additionfragmentation chain transfer raft polymerization is reported. Radical cationic acrylate vinyl ether radical figure 5. The reversible conversion of alkoxycarbenium to oxiranium ions results in a twostage reaction in which first, the epoxide, then the vinyl ether polymerization takes place. Methyl methacrylate can undergo radical as well as anionic polymerization. The improved synthesis and aqueous solution properties of hydroxyfunctional vinyl ether ohve copolymers with lower critical solution temperatures lcst in water are presented.
Polyvinyl chloride produced in bulk polymerization using monomer soluble free radical initiators. A series of ohve copolymers were directly prepared by free radical polymerization. Vinyl ethers of ethanolamines are less reactive in ionic polymerization than unsubstituted alkyl vinyl ethers, and they tend to undergo radical polymerization under the initiation of azodiisobutyronitrile. It enables the synthesis of very well defined polymers low molar mass distribution and of polymers with unusual architecture such as star polymers and block copolymers and living cationic polymerization is therefore as such of commercial and academic interest. Vinyl methyl ether monomers are much more selective with respect to ionic initiators. It is remarkable that only 10% addition of dve3 increases the conversion of the acrylate from.
Cationic polymerization of vinyl ethers controlled by. Thus the process of chain initiation involves two steps. Request pdf vinyl ethervinyl ester copolymerization by cationic and radical interconvertible simultaneous polymerization in this study, the concurrent cationic and radical interconvertible. The resulting polymers are produced under mild and controlled conditions and are useful in adhesives and coatings as well as in other uses such as for. The chain is initiated by free radicals, ra, produced by reaction between some of the ethene and the oxygen initiator. Pdf cationic polymerization of isobutyl vinyl ether in aqueous.
Allyl compounds, propene, isobutylene, vinyl ether cannot. Preferably, the vinyl ether monomers comprise up to about 35 equivalent % of the formulation particularly about 0. For example, the stateoftheart method uses a phenoxideligated titanium complex to achieve 92% meso diads % m in the polymerization of isobutyl vinyl ether ibve. The first orthogonal ferrocene monomer, namely vinyl ferrocene glycidyl ether vfcge, has been synthesized and polymerized via two different polymerization techniques. Synthesis of ultrahighmolecularweight pva using twostage.
View the article pdf and any associated supplements and figures for a period of 48 hours. The photoinitiated radical polymerization of difunctional vinyl ethermaleate mixtures has been studied by realtime i. Chemical engineering 160260 polymer science and engineering. Therefore, it was dif cult to prepare highmolecularweight pva. Synthesis of various poly2hydroxyethyl vinyl ether.
Copolymerization of butyl vinyl ether and methyl methacrylate by. Pdf cationic polymerization of isobutyl vinyl ether ibve in aqueous. The overall process is known as free radical addition. Chaingrowth polymerization has been successfully performed for many decades through conventional free radical, anionic, or cationic polymerization. To provide enough thermal stability, some polymerization inhibitor is added to the commercial product, which is a radical scavenger. To develop expressions for the average degree of polymerization and molecular weight distribution for anionic polymerization.
Vinyl ethers undergo radical initiated copolymerization in the presence of specific monomers such as maleates, fumarates, and acrylics. They are increasingly used in radiation curing systems because of a lower toxicity profile than the commonly used acrylic monomers. The polymerization inhibitor used for the stabilization of vinyl acetate monomers is hydroquinone h. A study was made of the polymerization of some vinyl ethers of ethanolamines in presence of ionogenic and free radical catalysts.
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