Copolymers methacrylate structures

Brown, D., Natansohn, A., Rochon, P. (1995). Azo polymers for reversible optical storage 5. Orientation and dipolar interactions of azobenzene side groups in copolymers and blends containing methyl methacrylate structural units. Macromolecules 28, 6116-6123. 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acrylic sheet. PMMA is also used in molding and extrusion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acrylic latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic structure, acetone is found in the following major end use products acrylic sheet molding resins, impact modifiers and processing aids, acrylic film, ABS and polyester resin modifiers, surface coatings, acrylic lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see Methacrylic acid and derivatives Methacrylic polymers). 

Random copolymer addition to binary blends involving copolymers with structural units equal or similar to the blend components or with specific interacting groups capable of non-reactive interaction with one of both the blend components comprises another ternary polymer addition approach. An early example involved EPR (ethylene-propylene rubber) addition to HDPE/PP blends, where synergistic impact strength was observed. In some cases, the random copolymers have been compared to block copolymers comprised of the same units. The compatibihzation of LLDPE/PMMA and LLDPE/poly(MMA-co-4-vinyl pyri-dine(4VP)) blends with poly(ethylene-co-methacrylic acid) (EMAA) addition were compared [47]. Modest improvements in LLDPE/PMMA dispersion and strength were observed. The specific acid-base interaction allowed for much larger improvements with EMAA addition to LLDPE/PMMA-CO-4VP blends. 

The term acrylic resin is generally applied to the polymers and copolymers of methacrylic and acrylic acid having structures (9) and (10), where R is the alkyl radical of the alcohol portion of the ester. Frequently the copolymers of one or more of these esters with nonacrylic monomers such as styrene, butadiene or vinyl acetate are also referred to as acrylic resins, but usage of the term is usually reserved for those resins which are predominantly of the characteristic acrylic or methacrylic structure shown. The main properties imparted by the acrylics as a class are outstanding outdoor... 

It is not the purpose of this book to discuss in detail the contributions of NMR spectroscopy to the determination of molecular structure. This is a specialized field in itself and a great deal has been written on the subject. In this section we shall consider only the application of NMR to the elucidation of stereoregularity in polymers. Numerous other applications of this powerful technique have also been made in polymer chemistry, including the study of positional and geometrical isomerism (Sec. 1.6), copolymers (Sec. 7.7), and helix-coil transitions (Sec. 1.11). We shall also make no attempt to compare the NMR spectra of various different polymers instead, we shall examine only the NMR spectra of different poly (methyl methacrylate) preparations to illustrate the capabilities of the method, using the first system that was investigated by this technique as the example. 

Materials containing the above structure in the polymer chain may be made from copolymers of methacrylic acid and methacrylonitrile. Ammonia-producing additives (such as urea and ammonium hydrogen carbonate) are added to the... 

Scheme 1 Schematic structure of graft block copolymer [51] TTTm = polymethyl methacrylate segment w AA = po-lydimethylsiloxane segment.

For flexible chain copolymers based on acrylic and methacrylic acids (AA and MA) crosslinked with a polyvinyl component, the inhomogeneity of the structures formed depends on the nature of the crosslinking agent, its content in the reaction mixture and the thermodynamic quality of the solvent [13,14],... 

The salt effect is very strong in polyconjugated polyelectrolytes. Figure 15 is a graph of the proton dissociation energy vs. the dissociation degree of PPA of different structures. Also, the graphs for poly(methacrylic acid) and a copolymer... 

The incidence of the various structures depends strongly on the comonomer. In copolymerization with acrylates structures 62 and 63 dominate. In copolymerization with VAc structure 61 dominates and 62 and 63 arc not observed. Structure 60 may be present in VAc copolymers to a very small extent but is not observed in acrylate copolymerizations. Structures 62 and 63 arc not observed and cannot be formed in methacrylate copolymerizations.290 The results were interpreted"90 in terms of the PVAc propagating radical having a lesser... 

IUPAC recommendations suggest that a copolymer structure, in this case poly(methyl methacrylate-co-styrene) or copoly(methyl methacrylate/slyrene), should be represented as 1. The most substituted carbon of the configurational repeat unit should appear first. This same rule would apply to the copolymer segments shown in Section 7.1. However, as was mentioned in Chapter I, in this book, because of the focus on mechanism, we have adopted the more traditional depiction 2 which follows more readily from the polymerization mechanism. 

With diblock copolymers, similar behavior is also observed. One component is enriched at the surface and depending on miscibility and composition a surface-induced ordered lamellar structure normal to the surface may be formed. Recent investigations include poly (urethanes) [111], poly(methoxy poly (ethyleneglycol) methacrylate)/PS [112] and PS/PMMA [113, 114]. In particular the last case has been extensively studied by various techniques including XPS, SIMS, NR and optical interferometry. PS is enriched at the surface depending on blockcopolymer composition and temperature. A well ordered lamellar structure normal to the surface is found under favourable conditions. Another example is shown in Fig. 6 where the enrichment of poly(paramethylstyrene), PMS(H), in a thin film of a di-... 

ABA type poly(hydroxyethyl methacrylate) (HEMA) and PDMS copolymers were synthesized by the coupling reactions of preformed a,co-isocyanate terminated PDMS oligomers and amine-terminated HEMA macromonomers312). Polymerization reactions were conducted in DMF solution at 0 °C. Products were purified by precipitation in diethyl ether to remove unreacted PDMS oligomers. After dissolving in DMF/toluene mixture, copolymers were reprecipitated in methanol/water mixture to remove unreacted HEMA oligomers. Microphase separated structures were observed under transmission electron microscope, using osmium tetroxide stained thin copolymer films. 

Using these macroinitiators PDMS-polystyrene and PDMS-poly(methyl methacrylate) multiblock copolymers were synthesized 305). Due to the backbone Structure of these macroinitiators and their thermolysis mechanisms, the copolymers obtained... 

A variety of ionomers have been described in the research literature, including copolymers of a) styrene with acrylic acid, b) ethyl acrylate with methacrylic acid, and (c) ethylene with methacrylic acid. A relatively recent development has been that of fluorinated sulfonate ionomers known as Nafions, a trade name of the Du Pont company. These ionomers have the general structure illustrated (10.1) and are used commercially as membranes. These ionomers are made by copolymerisation of the hydrocarbon or fluorocarbon monomers with minor amounts of the appropriate acid or ester. Copolymerisation is followed by either neutralisation or hydrolysis with a base, a process that may be carried out either in solution or in the melt. 

This paper presents the physical mechanism and the structure of a comprehensive dynamic Emulsion Polymerization Model (EPM). EPM combines the theory of coagulative nucleation of homogeneously nucleated precursors with detailed species material and energy balances to calculate the time evolution of the concentration, size, and colloidal characteristics of latex particles, the monomer conversions, the copolymer composition, and molecular weight in an emulsion system. The capabilities of EPM are demonstrated by comparisons of its predictions with experimental data from the literature covering styrene and styrene/methyl methacrylate polymerizations. EPM can successfully simulate continuous and batch reactors over a wide range of initiator and added surfactant concentrations. 

As the majority of stabilisers has the structure of aromatics, which are UV-active and show a distinct UV spectrum, UV spectrophotometry is a very efficient analytical method for qualitative and quantitative analysis of stabilisers and similar substances in polymers. For UV absorbers, UV detection (before and after chromatographic separation) is an appropriate analytical tool. Haslam et al. [30] have used UV spectroscopy for the quantitative determination of UVAs (methyl salicylate, phenyl salicylate, DHB, stilbene and resorcinol monobenzoate) and plasticisers (DBP) in PMMA and methyl methacrylate-ethyl acrylate copolymers. From the intensity ratio... 

Ethylene vinyl acetate has also found major applications in drug delivery. These copolymers used in drug release normally contain 30-50 wt% of vinyl acetate. They have been commercialized by the Alza Corporation for the delivery of pilocarpine over a one-week period (Ocusert) and the delivery of progesterone for over one year in the form of an intrauterine device (Progestasert). Ethylene vinyl acetate has also been evaluated for the release of macromolecules such as proteins. The release of proteins form these polymers is by a porous diffusion and the pore structure can be used to control the rate of release (3). Similar nonbiodegradable polymers such as the polyurethanes, polyethylenes, polytetrafluoroethylene and poly(methyl methacrylate) have also been used to deliver a variety of different pharmaceutical agents usually as implants or removal devices. 

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