Copolymers with fumarates

On the contrary in copolymers with fumarates, upfield components are clearly observable only in samples with NVC content larger than 60 %, indicating the occurrence of short NVC sequences and in accordance with the suggested quasi alternating structure... 

For unplasticized chlorinated PVC, unplasticized chlorinated polymer blends of vinyl chloride and mixtures of these copolymers with other polymer blends, the following starting materials can be used PVC (homopolymer) polymer blends of vinyl chloride, vinylidene chloride, trans-dichloroethylene, ethylene, propylene, butylene, maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid as well as chlorine. 

Figure 8. Concentration of different radicals measured from ESR spectra during copolymerization of vinyl acetate (VAc) with maleic acid (MA) ana of VAc with fumaric acid (FA) at different molar concentrations of MA in the VAc-MA system and FA in the VAc-FA system, respectively. (VAc-) and (MA-) refer to monomer radicals and (VAc-MA-) and (VAc-MA-) to the copolymer radicals observed. [VAc] = 5.5 X 10 2M ...

The parameters rA and rs are known as monomer reactivity ratios representing the ratio of rate constants for a radical to add to its own type polymer vs. rate constants for a radical to add to the other type polymer. When kAA = 0 and ksB = 0, it can be seen that rA = 0, re = 0, and each radical reacts exclusively with the other monomer. Rel. (2.3.20) is then reduced to d[P ]/d[P ] = 1, and the monomers alternate regularly along the chain of the copolymer, regardless of the composition of the monomer feed (an excess of one monomer may remain unreacted). This is an ideal case, but copolymers such as that made from (a) styrene and (b) diethyl fumarate (rA = 0.3, re = 0.07) can be close to the ideal case. The styrene/diethyl fumarate polymerization has the tendency to lead to an azeotropic copolymer with 57 mole percent styrene, regardless the feed composition. When the initial composition of the monomers is different from 57 mole percent, the alt-copolymer is formed until one of the materials is finished and the remaining monomer forms a homopolymer. 

Copolymers with silanes have attracted much interest. These include a range of methacrylic acid copolymers with disilanes, secondary silanes, phenylsi-lane and fumarate terminated poly(dimethylsiloxanes). A platinum(II) bis(a-cetylacetonato) catalyst has been found to be highly effective for enhancing the activities of hydride and vinyl polymer end groups in step polymerisation reactions. ... 

Copolymers with 15% of maleate and fumarate esters afford good processing properties with only a mild impairment of physical properties. Heat distortion temperature is relatively high. 

Similar data analysis was applied also to copolymers of sebacic acid with fumaric acid [40], CPH [61], and trimellitimide derivatives [51]. Based on the HNMR analysis, a FA-FA or SA-SA dimer alternating structure (-SA-SA-FA-FA-SA-SA-FA-FA) was suggested for P(FA-SA) 1 1. In the case of copolymers of the asymmetric trimellitimide comonomer (represented by the letters B1 or B2) with the symmetric comonomers sebacic add or CPH (represented by the letter A), 6 diad sequences were expected to be present in the polymer backbone (A-A, A-Bl, A-B2, Bl-Bl, B1-B2, B2-B2) and they were identified by NMR spectroscopy. Due to partially overlapping peaks in some of the copolymers, some assumptions were made. A typical data from this analysis is shown in Table 14. 

PPE-grafted with fumaric acid, reactively blended with PC and SEES Grafted PPE, blended with dimethylsiloxanes, PC, PBT, and SEES PPE, with PBT, PC, SEES and/or acrylate copolymer... 

Excimer formation has been studied in polystyrene and poly(a-alkylstyrenes)189 (PS), poly(vinylcarbazole),139>140 poly-(2-vinylnaphthalene), and poly-(4-vinyl-biphenyl).141 For polystyrene films, David et a/.189 showed that the fluorescence yield increased with increasing crystallinity, at both ambient temperature and 77 K. The contribution of excimer fluorescence yield increased in the sequence atactic (0.7) < atactic oriented (0.60) < isotactic amorphous (0.28) < isotactic crystallized (0.01), with normal yields relative to excimer given in parentheses. Similar results were obtained for poly(vinylcarbazole), PVCZ, although the contribution of excimer fluorescence at 77 was independent of crystallinity. The results can be interpreted in terms of electronic energy migration to low-energy defect sites from which excimer emission can occur. In PVCZ copolymers with fumaronitrile (10), diethyl fumarate (11), and diethyl maleate (12) (Scheme 6),... 

Poly(vinyl acetate) latex is used in the production of water-based emulsion paints, adhesives, and textile and paper treatments. Emulsion paints are stable, dry quickly, and are relatively low cost. PVAC emulsion adhesives are used in labeling and packaging, and as the popular consumer white glue. Copolymers with dibutyl fumarate, vinyl stearate, 2-ethylhexyl acrylate, or ethyl acrylate are used to obtain compositions that are softer for emulsion use. As indicated above, a major use of poly(vinyl acetate) is in the production of poly(vinyl alcohol), which is itself the starting material for poly(viityl butyral) and poly(vinyl formal). 

A number of copolymers are known where vinyl acetate is the major component. In coatings, vinyl acetate is often used in copolymers with alkyl acrylates (line 2-ethylhexyl acrylate) or with esters of maleic or fumaric acids. Such copolymers typically contain 50-20% by weight of the comonomer and are usually formed by emulsion polymerization in batch processes. They are used extensively as vehicles for emulsion paints. 

Influences due to steric hindrance are mostly swamped by those due to polarity and resonance stabilization. For example, 1,2-disubstituted ethylene monomers form random copolymers with comonomers of similar polarity, i.e., dimethyl fumarate/vinyl chloride. If the polarities differ greatly, even alternating copolymers can be formed because of the formation of CT complexes, as, for example, with maleic anhydride/styrene (see also Section 22.3). Even two 1,2-disubstituted monomers copolymerize with each other if the polarities differ very greatly, as happens with, for example, maleic anhydride and stilbene, since the polar interaction in the transition state helps to overcome the steric hindrance. Threefold substituted olefins produce an additional stabilization without steric hindrance in the transition state, and so can be easily copolymerized with comomoners of opposite polarity. 

Poly(s-caprolactone) (PCL) is a semicrystalline, aliphatic polyester (Structure 3). Itis soluble in tetrahydrofuran, chloroform, methylene chloride, carbon tetrachloride, benzene, toluene, cyclohexanone dihydropyran, and 2-nitropropane and only partially soluble in acetone, 2-butanone, ethyl acetate, acetonitrile, and dimethyl fumarate [33]. PCL is also capable of forming blends as well as useful copolymers with a wide range of polymers [34]. 

Copolymers. Vinyl chloride can be copolymerized, with vinyl acetate giving a polymer wi a lower softening point and better stability than pure PVC. The compositions can vary from 5 to 40 percent vinyl acetate content. This material has application in areas where PVC is too rigid and the use of plasticized PVC is unacceptable. Flooring is one application for these copolymers. Copolymers with about 10 percent vinylidene chloride and copolymers with 10 to 20 percent diethyl fumarate or diethyl maleate are also available. 

With compositions close to the preferred styrene polyester ratio, the overall rate of conversion depends on the reactivity of styrene with maleate and fumarate, the ratio of maleate to fumarate in the polyester, and the reactivity of styrene with itself. Data from the literature on relevant reactivity ratios are conflicting, but the consensus of evidence is that styrene is more reactive with fumarate than with maleate and is more reactive with either than with itself. Similarly, maleate/fumarate is more reactive with styrene than with itself, hence the tendency to form alternating copolymers from styrene and maleate/fumarate unsaturation. Methyl methacrylate is sometimes used as a component in unsaturated polyesters to reduce refractive index and thereby derive aesthetic variations when the polymers are filled with particulates or glass. However, methyl methacrylate could not wholly replace styrene in polyester resins because, unlike styrene, methyl methacrylate is much more reactive with itself than... 

Unsaturated Poly (fumaric anhydride) Poly (4,4 -stilbene dicarboxylic acid anhydride) Homopolymers are crystalline and insoluble in organic solvents, copolymers with aliphatic acids renders it less crystalline and soluble in chlorinated hydrocarbons. 

Biodegradable copolymers of fumaric anhydride and isophthalic anhydride were synthesised by the melt condensation polymerisation of purified prepolymer mixtures and formulated into microspheres loaded with theophylline and diltiazem hydrochloride using a solvent extraction procedure. The important parameters of the microencapsulation process were identified and in vitro... 

As mentioned previously, the Alfrey Priee Q and e values for vinyl acetate are 0.026 and —0.22, respectively [226]. Thus vinyl acetate is rather sluggish in its free-radical copolymerization, with most monomers, particularly olefinic monomers, bearing electron-donating subtitutents. The copolymerization reactivity ratios reflect the reluctance of vinyl acetate to enter into copolymerization with other monomers [270]. Nevertheless, vinyl acetate copolymers with a great many electron-rich as well as electron-poor olefins have been prepared. Especially significant from a commercial point of view are copolymers with ethylene, vinyl chloride, acrylates, methacrylates, fumarates, and maleates. Often, mixtures of three and more comonomers are used in these copolymerizations. 

Not all the monomers listed in Table 1 react together satisfactorily thus vinyl acetate and styrene, ethylene and styrene, are examples of unfavourable pairs. Moreover, monomers without terminal unsaturation, e.g. the fumarates, and the related maleates, do not generally form homopolymers although readily forming copolymers with, for example, vinyl acetate. 

Polyethylene can be crosslinked with peroxides to make it more suitable for coatings for electrical power cables [18]. Peroxides are also used to crosslink (also called cure) thermoset polyesters. Thermoset polyesters have a reactive alkene and are used to make fiberglass compositions such as used for boat hulls. Variations are possible, but commonly they are copolymers of fumaric acid or maleic anhydride with phthalic acid or isophthalic acid and a diol. The oligomer is typically dissolved in styrene. When a peroxide is mixed with the solution, crosslinking occurs and the polyester cures. The styrene solvent takes part in the reaction and the solution hardens. 

As reported, AABB type PEAs of fumaric acid display limited solubility in common organic solvents. In most cases the polymerization solution turns to gel, due to partial crosslinking (10). We have observed that unsaturated PEA (UPEA) copolymers with less than 35 % mol. ratio of fumaric acid to aliphatic diacid maintain reactivity during radical reactions and remain soluble over long storage periods. 

Monomers with electron-rich double bonds produce one-to-one copolymers with monomers having electron-poor double bonds in reaction systems that also contain certain Lewis acids. These latter are halides or alkyl halides of nontransition metal elements, including AlCb, ZnCh, SnCL, BF3, AI(CH2CH3)Cl2, alkyl boron halides, and other compounds. The acceptor monomer generally has a cyano or carbonyl group conjugated to a vinyl double bond. Examples are acrylic and methacrylic acids and their esters, acrylonitrile, vinyl ketones, maleic anydride, fumaric esters, vinylidene cyanide, sulfur dioxide, and carbon monoxide. The variety of donor molecules is large and includes various olefins, styrene, isoprene, vinyl halides and esters, vinylidene halides, and allyl monomers [30]. 

The patent literature discloses that several speciality-type acrylate monomers, such as /3-hydroxyethyl acrylate,2-acrylyloxyethyl phenyl carbonate,vinyl acrylate,2,2,2-trifluoroethyl acrylate, N,N-dimethylaminoethyl acrylate,glycidyl acrylate,cyanoacrylates,and several diacrylates,have been copolymerized with MA. These copolymers were shown to exhibit properties which allowed the materials to be useful for polymeric emulsifiers, adhesives, " printing pastes,fire retardant textile coatings, and fibrous structural materials.Maleate and fumarate copolymers with acrylates also show possible utility in coatings, dispersants, adhesives, and other applications. Cyanoacrylate adhesives have much improved heat resistance... 

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