Poly-0-methyl-0-lactone

Controlled block copolymerization of olefins with polar monomers was performed with a lanthanide complex by the successive polymerization of hexene (or pentene) and methylmethacrylate (or caprolactone). Polyhexene-block-poly(methyl methacrylate), polyhcxcnc-fo/ock-polycaprolactone, poly-pentene-fc/ock-poly(methyl methacrylate), and polypentene-Wock-polycapro-lactone were synthesized using a lanthanide complex as initiator [140-143]. 

The polymerized acrylamide was completely bound in the graft since no homopolyacrylamide was found. Block polymers have been prepared by linear grafting 11). Eosin lactone was appended to poly (methyl methacrylate) chains by means of a terminal amino group to provide a polymeric initiator which was then used to photoinitiate polymerization of styrene and acrylamide. 

The most direct way of looking at the specific interactions is by using spectroscopic measurements. Infra-red spectroscopy is the technique which has been most commonly used to study mixtures involving polymers. Studies of blends of PVC with polycaprolactone showed shifts of 4-6 cm 1 in the carbonyl band of polycapro-lactone relative to the pure polymer 99 l00), but this Figure should be treated with caution as the peak probably consists of the sum of a shifted and an unshifted peak and it is difficult to say what the frequency of the shifted peak would be, or what fraction of the carbonyl groups are, or can be, involved in the interaction. Frequency shifts have also been shown to exist in blends of poly(methyl methacrylate) with poly(vinylidene fluoride)63). 

The wide applicability of aluminum porphyrin initiators (1) leads to a variety of tailored block copolymers such as polymethacrylate-polyether and polymethacrylate-polye-ster, as well as polymethacrylate-polymethacrylate and polymethacrylate-polyacrylate, that can be synthesized by sequential living polymerization of the corresponding monomers.- For example, when 1,2-epoxypropane (11, R = Me) is added to a polymerization mixture of methyl methacrylate (21, R = Me) with la at 100% conversion of 21, the polymerization of 11 takes place from the enolate growing end (32 ) to give a narrow MWD polymethacrylate-polyether block copolymer having an alcoholate growing terminal (Table 4). Likewise, the aluminum enolate species (32 ) can also react with lactones (14,15), thereby allowing the formation of a poly(methyl methacrylate)-polyester block copolymer with narrow MWD. 

Albery et al. [39, 49] prepared poly(3-thiopheneacetic acid) and its copolymer with thiophene by electrochemical polymerization. Bartlett et al. [50] electrochemically synthesized conducting poly(3-thiophene-acetic acid) films in dry acetonitrile containing tetraethyl ammonium tetrafluoroborate. These films are redox active in acetonitrile, however, stability was reportedly poor in comparison with poly(3-methylthio-phene) and poly(methyl 3-thiopheneacetate) due to traces of water. In dry acetonitrile, the polymer can be electrochemically oxidized and reduced. Upon oxidation in water and methanol, poly(3-thiopheneacetic acid) film converted into a passive film. Based on the electrochemistry and an FT-IR study, Bartlett et al. postulate the mechanism for the electrochemical passivation shown in the Figure 4.33. In the mechanism, passivation of the polymer involves the formation of an intermediate cyclic lactone and subsequent breakdown by reaction with solvent. This process does not destroy the conductivity of the polymer so the process can continue until all the monomer units within the film are converted to a lactone form (Figure 4.33, IV). The electrochemical passivation is not observed... 

Poly(itaconic acid) has also been prepared in a 0.2M/liter aqueous solution using potassium persulfate at 50 C over a 5-hr period under reduced pressure. After the polymer is reprecipitated twice into methanol-ethyl acetate, a polymer is isolated with a molecular weight of 1.64 x 10, determined by vapor pressure osmometry of a methanolic solution of the methyl ester prepared from the polymer [49]. Unfortunately Tsuchida and coworkers did not report on the quantitative extent to which poly(methyl itaconate) had been formed from this polymer (presumably by reaction with diazomethane). Consequently, there is little in the literature to confirm or dispute the paper by Braun and Azis el Sayed [97], which offered evidence that during the free-radical polymerization of itaconic acid, carbon dioxide evolves to a considerable extent. During the process, it seems that hydroxyl and formyl radicals are generated and incorporated in the macromolecule. It is proposed by these authors that the homopolymer of itaconic acid contains virtually no itaconic acid repeat units but rather intramolecular lactone rings and acetal- or hemiacetal-like moieties. Since the polymer remains soluble in the reaction solvent (dioxane). 

PMR spectroscopy has been applied to the characterisation of a wide range of homopolymers including PMMA [286-289], PVC [290-294], PS [293, 295, 296], polyvinyl ethers [297-300], polyacrylic acid [301], poly(methyl-a-chloroacrylate) [302], carboxy terminated polybutadiene [303], poly(a-methyl styrene) [304], natural rubber [305-307], chlorinated polyisobutylenes [308], sulfonated PS resins [309, 310], polyvinyl phenyl ether [311], lactone polyester [312], chlorinated PVC [313], PC [314], poly 1,3 butadiene [315], poly-2-allyl phenyl acrylate [316], poly(4-methyl-pentene-1) [317], polymethacrylic acid [318], PP [296], cyclic ethers [319], polymethacrylonitrile [320], poly(a-methyl styrene) tetramer [321], PEG [322], PE [289], polyacrylamide [311], polymethylacrylamide [323], polypyrrolidone [324], polychloroprene [325], phenol formaldehyde resins [326, 327], Nylon 66 [328], polyvinylidene fluoride [329], polyvinyl formate [330], polyacrylonitrile [331], epoxy resins [332], allyl biguanide [333], poly(2-isopropyl-2-oxazollines) [334] and trehalose vinyl benzyl ether [335]. 

The poly 6 -a,jS-dimethoxysuccinate was crystalline. The early works in this field since 1965 are due to the Overberger group [120—121] which describe the synthesis of OA poly-methyl-substitued-e-caprolactones (XLIXa, b, c) and of their model compounds via the lactone. An aluminum-triisobutyl/water co-catalyst system converts them into high molecular weight polymers. No special conformation was detected for these polymers in solution, as there is a linear decrease in the ratio of the Cotton effect extrema for the 8-methyl polymer and its model compound as a function of decreasing size, and absence of any Cotton effect for the 7-methyl and the 6-methyl polymer in good (tetrafluroethanol) or poor solvents ( -amyl alcohol and dioxane). The Drude equation was followed in all solvents studied and the values correspond to those UV bands which are optically active. 

Interestingly, enzymes are chiral catalysts and their potential for enantio-selective polymerization has been investigated [93]. Several examples are reported where a racemic mixture of lactones is polymerized by enzymatic polymerization to afford the corresponding optically active polyester [93]. For instance, lipase CA (Novozym 435) catalyses the ROP of racemic 4-methyl-s-caprolactone and 4-ethyl-s-caprolactone in bulk at 45 °C and 60 °C to afford (S )-eiuiched poly(4-methyl-e-caprolactone) and poly(4-ethyl- -caprolactone) with an enantiomeric purity higher than 95% [153]. 

This paper presents data on isolation and identification of the following types of geolipids from the Aleksinac oil shale, a Miocene lake sediment n-al-kanes, iso- and/or anteiso-alkanes, aliphatic iso-prenoid alkanes, polycyclic isoprenoid alkanes, aromatic hydrocarbons, saturated unbranched, aliphatic isoprenoid, hopanoic, and aromatic mono- and poly-carboxylic acids, fatty acid methyl esters, aliphatic y- and 6-lactones, cyclic y-lactones, aliphatic methyl- and isoprenoid ketones, and the triterpenoid ketone adiantone. Possible origin of the identified compound classes is discussed, particularly of those which had not been identified previously as geolipids. 

Helical conformations with two monomer units per turn appear to be general for polymers from B lactones.(18) Fiber repeat distances may vary, but not by a great amount. Examples are polyproplolactone and poly(D,L-or-methyl-a-n-propyl-B-proplolactone). Both are converted to a planar zig-zag form by stretching and both reverts to a helical configuration upon annealing. 

Poly(acrylates) and (alkyl acrylates). - Structured nanopore films of poly(styrene-block-methyl methacrylate) copolymers have been made with controlled spectral sensitivity, such that each block is sensitive to a specific degradation wavelength. In copolymers of 2,2,2-trifluoroethyl methacrylate with vinyl ethers, the photosensitivity is controlled by the vinyl ether units. Photodegradation occurs at the tertiary positions of the ether units followed by lactone formation and chain scission processes. Furthermore, the fluorinated side chains have been found to inhibit cyclization reactions. 

Coextrusion of L-lactide (a cyclic dimer lactone of lactic acid) with hydroxy-terminated poly(caprolactone) in the presence of stannous octoate gave a block copolymer.74 Block copolymers can also be used as compatibilizers for the homopolymers, in addition to having interesting properties in their own right.75 Copolymers of ethylene and vinyl acetate can be treated with methanol and a little sodium methoxide to remove some of the acetate groups from the copolymer.76 The by-product methyl acetate comes out the vent of the extruder. n-Butyl alcohol can be used in the same way.77 The product copolymer is useful as a gas barrier coating on films for packaging food. 

The extruder can be used for a variety of polymerizations even if no preformed polymer is present.89 These include the continuous anionic polymerization of caprolactam to produce nylon 6,90 anionic polymerization of capro-lactone 91 anionic polymerization of styrene 92 cationic copolymerization of 1,3-dioxolane and methylal 93 free radical polymerization of methyl methacrylate 94 addition of ammonia to maleic anhydride to form poly(succin-imide) 95 and preparation of an acrylated polyurethane from polycaprolactone, 4,4 -methylenebis(phenyl isocyanate), and 2-hydroxyethyl acrylate.96 The technique of reaction injection molding to prepare molded parts is slightly different. Polyurethanes can be made this way by... 

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