DIETHYL MALEATE COPOLYMER

Billiani and co-workers [90] observed that pyrolysis of styrene-maleic anhydride copolymer and styrene diethyl maleate at 450 °C produced products of toluene, ethyl benzene, styrene monomer from the maleic anhydride and diethyl fumarate copolymers and styrene oligomers from the styrene diethyl maleate copolymers. 

The first free radical initiated copolymerization was described by Brubakerl) in a patent. A variety of peroxides and hydroperoxides, as well as, 02, were used as initiators. Olefins that were copolymerized with CO included ethylene, propylene, butadiene, CH2=CHX (X—Cl, OAc, CN) and tetrafluoroethylene. A similar procedure was also used to form terpolymers which incorporated CO, C2H4 and a second olefin such as propylene, isobutylene, butadiene, vinyl acetate, tetrafluoroethylene and diethyl maleate. In a subsequent paper, Brubaker 2), Coffman and Hoehn described in detail their procedure for the free radical initiated copolymerization of CO and C2H4. Di(tert-butyl)peroxide was the typical initiator. Combined gas pressures of up to 103 MPa (= 15,000 psi) and reaction temperatures of 120—165 °C were employed. Copolymers of molecular weight up to 8000 were obtained. The percentage of CO present in the C2H4—CO copolymer was dependent on several factors which included reaction temperature, pressure and composition of reaction mixture. Close to 50 mol % incorporation of CO in the copolymer may be achieved by using a monomer mixture that is >70 mol% CO. Other related procedures for the free radical... 

Terpolymers made from two different olefins and CO are known. They were first described in Brubaker s initial patent and involved the free radical initiated terpolymerization of CO and C2H with another olefin such as propylene, isobutylene, butadiene, vinyl acetate, diethyl maleate or tetrafluoroethylene More recently, in another patent, Hammer has described the free radical initiated terpolymerization of CO and C2H with vinyl esters, vinyl ethers or methyl methacrylate 26Reaction temperatures of 180-200 °C and a combined pressure of 186 MPa were employed. Typically a CO QH4 olefin molar ratio of 10 65 25 was observed in the terpolymers. In other patents, Hammer 27,28) has described the formation of copolymers with pendant epoxy groups by the free radical initiated polymerization of CO, QH4, vinyl acetate and glycidyl methacrylate. Reaction conditions similar to those stated above were employed, and a typical CO C2H vinyl acetate glycidyl methacrylate molar ratio of 10 65 20 5 was observed in the product polymer. 

As background information, an attempt was made to copolymerize cis-2-butene-l,4-diol diacetate with MA. Heating equimolar mixtures of the two monomers with AIBN (2 wt%) for 15 hr. at 75°C produced only a very low yield (<10%) of polymeric material. Using the same conditions, equimolar mixtures of IA-di-t-butyl fumarate and IA-dimethyl maleate gave only a trace of copolymer. Yokayama and Hall (10) also repored that diethyl maleate and diethyl fumarate undergo free-radical copolymerization with IA to give very low yields of non-equimolar 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),... 

A comparative study of MAH and diethyl maleate grafting—initiated by DCP—to styrene-(ethylene-butylene)-styrene triblock copolymer (SEES) and PS blended with a random ethylene-1-butene copolymer has been described elsewhere (66). The weight ratio of PS to PO components in the block copolymer was the same as in the blend (20% PO and 80 wt% PS). The analysis of the functionalized PS/PO blend—after PS had been extracted in a solvent—showed that the monomer was grafted only to the PO component. Considering that the PS/ PO blend and SEES have quite similar phase and molecular structures, it was concluded that in styrene-containing block copolymers only aliphatic blocks become functionalized. 

BEL Beldie, C., Nemtoi, G., Dumitriu, E., and Baiboiu, V., The behaviour of diethyl maleate-vinyl acetate copolymers in solution. Rev. Roum. Chim., 34, 51, 1989. 

Elvaron. See Dichlofluanid Elvax 40P, Elvax 40-W, Elvax 140-W, Elvax 15a, Elvax 150-W, Elvax 200-W, Elvax 205-W, Elvax 210-W, Elvax 220-W, Elvax 240, Elvax 240-W, Elvax 250, Elvax 250-W, Elvax 260, Elvax 265, Elvax 310, Elvax 350, Elvax 360, Elvax 410, Elvax 420, Elvax 450, Elvax 460, Elvax 470, Elvax 500-V 7, Elvax 550, 560, Elvax 565, Elvax 650 Elvax 660 Elvax 670, Elvax 750, Elvax 3120 Elvax 3128 Elvax 3135SB Elvax EP170-PS Elvax EVA 3135X. See EthyleneA/A copolymer EM. See Diethyl maleate EM. See Methoxyethanol EM-1. See Lard oil... 

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. 

SEM photomicrographs of the 70/30 PET/LDPE+diethyl maleate grafted ultra-low-density polyethylene (ULDPE-g-DEM) blends obtained with a mixing time of 20 min. (A) and (B) no copolymer, sample cut parallel to flow direction (C) no copolymer, sample cut perpendicular to flow direction. (From M. B. Coltelli, Catalysed Reactive Compatibilization of Polyolefin and Poly(ethyIene terephthalate) Blends Reactions Mechanisms and Phase Morphology Development, Ph.D. thesis. University of Pisa, Italy, 2005.)... 

Maleate esters such as dimethyl maleate, diethyl maleate and dibutyl maleate are extensively used in the production of latex emulsion polymers, thermoplastic and thermosetting plastics. Dimethyl maleate has found use in applications where improvement in hardness and toughness of polymer films are desired. This includes, in particular, the improvement of anti-blocking properties of copolymers of vinyl acetate with dimethyl maleate. It is also used as an internal modifier to increase the glass transition temperature of styrene or vinyl chloride polymer. The intermediate in esterification of maleic acid with methanol, monomethyl maleate provides plastsizing effect, as well as promotion of improved polymer adhesion due to the carboxylic group. It can be copolymerized with a variety of vinyl and acrylic monomers to provide coatings with improved stiffness and adhesion and reduced tackiness or tendency to block. Monoesters of maleates are used to provide carboxylic acid functionality in emulsions and water-soluble polymers. 

A limitation of external plasticizers of this kind is that they may eventually be lost by evaporation or by migration into the substrate, leaving an imperfect and brittle film. This limitation may be overcome by the use of copolymers and these are now widely used in surface coatings and other applications. Comonomers which may be employed for this purpose include butyl acrylate, 2-ethylhexyl acrylate, diethyl fumarate, diethyl maleate and vinyl esters of fatty acids (e.g. a branched Cio fatty acid). Typically, the copolymers contain 15-20% by weight of such comonomers. These copolymers are readily prepared by the emulsion polymerization techniques described previously for the homopolymer. 

---