Methacrylate monomers, physical properties

Methacrylate homopolymers, physical properties of, 16 272t Methacrylate inhibitors, 16 258-259 Methacrylate monomers, 16 277-279. 

Table 6. Physical Properties of Commercially Available Methacrylate Monomers CH 2 = C(CH3)C00R ...

Acrylic Polymers. Although considerable information on the plasticization of acryUc resins is scattered throughout journal and patent hterature, the subject is compHcated by the fact that acryUc resins constitute a large family of polymers rather than a single polymeric species. An infinite variation in physical properties may be obtained through copolymerization of two or more acryUc monomers selected from the available esters of acryUc and methacryhc acid (30) (see Acrylic esterpolya rs Methacrylic acid and derivatives). 

Monomers such as aUyl methacrylate and diaUyl maleate have appUcations as cross-linking and branching agents selected especiaUy for the different reactivities of their double bonds (90) some physical properties are given in Table 8. These esters are colorless Uquids soluble in most organic Uquids but htde soluble in water DAM and DAF have pungent odors and are skin irritants. 

The most stable resin for many of our purposes has proven to be a copolymer of ethyl methacrylate and methyl acrylate. This comes as little surprise the Rohm and Haas Company has for years sold a durable resin based on these two monomers, Acryloid B-72 (6,28). We have also prepared polymers of similar physical properties based on methyl methacrylate and ethyl acrylate and have found that their behavior is practically the same - the methyl and ethyl groups apparently do not become seriously involved in crosslinking. As reported elsewhere( 23), rather than crosslink, Acryloid B-72 tends to chain break under visible and near-ultraviolet radiation, although at a very slow rate. Polyvinylacetate is another polymer used in the care of museum objects that tends more to chain break than crosslink under these conditions(23), but it is not our purpose to discuss its properties at this time. 

See a/so Methacrylic ester monomers Methacrylic ester polymers Methacrylic monomers acute toxicity of, 16 260t exposure to, 16 261 for 193-nm resists, 15 178-179 physical properties of, 16 227-235t, 278t polymerization of, 14 259 Methacrylates... 

The initiation of polymerization by ultraviolet radiation has been of particular interest in the study of free radical processes [1,2]. The test tube demonstration described here is simple and may be used to evaluate the polymerizabil-ity of new monomers or to study some of the physical properties of a polymer. Although the method is particularly effective for acrylic and methacrylic monomers, it may also be applied to the polymerization of a wide range of vinyl -type monomers. 

In polymers that exhibit tacticity, the extent of the stereoregularity determines the crystallinity and the physical properties of the polymers. The placement of the monomer units in the polymer is controlled first by the steric and electronic characteristics of the monomer. However, the presence or absence of tacticity, as well as the type of tacticity, is controlled by the catalyst employed in the polymerization reaction. Some common polymers, which can be prepared in specific configuration, include poly(olefins), poly(styrene), poly(methyl methacrylate), and poly(butadiene). 

Acrylic Monomers. The physical properties of a polymer are dependent upon the monomers used in the polymerization. Impurities contained in the monomers also affect the physical properties. Acrylosilane resins and crosslinkable emulsions can be prepared using 3-(Diethoxymethylsilyl) propyl methacrylate (I) (H)). Free-radical polymerization using (I) will yield a resin... 

Taken together, acrylic and styrene-acrylic conqiositions account for nearly 30% of commercial emulsion polymers. The common practical element of these acrylic and methacrylic monomers is the ability to copolymerize well with each other and this leads to an enormous range of accessible compositions and physical properties such as glass transition temperature and solubility characteristics of the resulting polymers. Styrene (S) also copolymerizes reasoruiily well with acrylics, especially the aUyl acrylates, and is therefore included in this sense in the acrylic family. Homopolymers of S and methyl methacrylate (MMA) have similar glass transition temperatures and selection of one over the other in a copolymer may... 

Block copolymers of the ABA type made from hydrocarbon monomers by anionic polymerization have been extensively investigated (1, 2). Much less has been done with nonhydrocarbon block pol3niiers. Such systems as have been repotted show even broader temperature ranges of technical utility than the more familiar styrene/diene/styrene systems (3, 4, 5). It is the purpose of this paper to describe a process for preparing polymethyl methacrylate containing triblock copolymers. The physical property balances that can be gotten and the photooxidative degradation processes that occur will also be covered. 

Emulsion polymerization requires free-radical polymerizable monomers which form the structure of the polymer. The major monomers used in emulsion polymerization include butadiene, styrene, acrylonitrile, acrylate ester and methacrylate ester monomers, vinyl acetate, acrylic acid and methacrylic acid, and vinyl chloride. All these monomers have a different stmcture and, chemical and physical properties which can be considerable influence on the course of emulsion polymerization. The first classification of emulsion polymerization process is done with respect to the nature of monomers studied up to that time. This classification is based on data for the different solubilities of monomers in water and for the different initial rates of polymerization caused by the monomer solubilities in water. According to this classification, monomers are divided into three groups. The first group includes monomers which have good solubility in water such as acrylonitrile (solubility in water 8%). The second group includes monomers having 1-3 % solubility in water (methyl methacrylate and other acrylates). The third group includes monomers practically insoluble in water (butadiene, isoprene, styrene, vinyl chloride, etc.) [12]. 

Attempts have been made to reduce the dose required for cross-linking by sensitizers for example, by incorporation of 2,5-dichlorostyrene, the dose can be reduced from 30 to 1 Mrad, but unfortunately the rubber contains appreciable quantities of poly-2,5-dichlorostyrene and is too hard to be of any commercial value. Other monomers such as methyl methacrylate and acrylonitrile have been used, and in both cases the tensile strength of the irradiated rubbers is raised, but other physical properties are inferior. 

A study was made of the impact of incorporation of a small amount of carboxylic monomers (acrylic acid or methacrylic acid) into the latex particles in the limited flocculation process, often encountered in the semi-batch surfactant-free emulsion polymerisation of pure butyl acrylate. The possibility of producing carboxylated polybutyl acrylate latices with a smaller particle size was evaluated. The resultant latex was characterised to gain a better understanding of the effect of the surfactant-free technique on their physical properties, e.g. zeta potential, distribution of acrylic acid or methacrylic acid in the particles, and stability towards the added salt, compared with the conventional emulsion polymerisation system stabiUsed by surfactants. 35 refs. 

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