Natural rubber grafting copolymerization

When block and graft copolymers are dispersed in solvents, the solutions have properties that depend on whether or not the copolymer is eventually fully solvated. If the solvent is a good solvent for both sequences—for example, chloroform in the case of natural rubber graft copolymerized with poly(methyl methacrylate) (Halasa et al., 1976)—then both segment types are expanded and films cast from dilute solutions will usually be intermediate in properties to the... 

The first patent on HIPS, a blend of synthetic rubber and transparent polystyrene, was granted in Great Britain as early as 1912. The first graft copolymerization of styrene in the presence of rubber was carried out by Ostromislensky [5]. The decline in the demand for styrene monomer and styrene-butadiene rubber and the simultaneous availability of natural rubber on the world market in the late 1940s drove the development of styrene copolymer processes. 

Ceresa, R. J. "Synthesis and Characterization of Natural Rubber Block"and "Graft Copolymers in Block and Graft Copolymerization" Ceresa, R. J., Ed. John Wiley New York, 1973 Chap, 3. 

R.J.Ceresa, "Syntheses and Characterization of Natural Rubber Block and Graft Copolymers", in R.J. Ceresa ed.. Block and Graft Copolymerization, Volume 1, John Wiley, London, Chapter 3, 1973. 

N.M.Claramma, N.M. Mathew, and E.V.Thomas, Radiation induced graft copolymerization of acrylonitrile on natural rubber. Radiation Physics and Chemistry, 33 (2) pp. 87 -89,1989. 

Other compounds reacting similarly via activated double bonds (excluding here block or graft copolymerization) include maleic acid, A-methyl-maleimide, chloromaleic anhydride, fumaric acid, y-crotonolactone,/7-benzoquinone, and acrylonitrile. Other polymers with unsaturated backbones, such as polybutadiene, copolymers of butadiene with styrene and with acrylonitrile, and butyl rubber, react in similar ways, but the recorded reaction with poly(vinyl chloride) is largely mechanochemical in nature (discussed later). 

This type of graft copolymerization has been applied to the grafting of monomers like styrene and methyl methacrylate to natural rubber [271], directly in the latex [272,273]. Similar methods have been developed for grafting the foregoing monomers, and many other vinyl monomers, to synthetic rubbers like SBR, leading to a variety of plastic-reinforced elastomers and rubber-reinforced high-impact plastics [270,274]. In this case, grafting can also occur by the copolymerization of the monomer with the unsaturated bonds (mainly vinyl) in the polymer as described previously [see Eq. (96)] thus... 

The use of natural rubber latex to form graft copolymers (and eventually IPN-related materials) was one of the earlier methods of preparing rubber/plastic compositions. " " These materials are known as Heveaplus, which is a generic name of a series of raw materials made by graft copolymerization with other polymeric or resinous substances. Heveaplus MG, prepared by polymerizing methyl methacrylate in the rubber latex, has attracted the most attention. 

The preparation of natural rubber-gra/t-methyl methacrylic acid has been reported by Lenka and coworkers. The vanadium ion was used as an initiator, which initiated the creation of free radicals on the backbone of natural rubber and this increased the interaction between the natural rubber and the methyl methacrylate surfaces. The coordination complexes derived from the acetylacetonate of Mn(III) ions could also be used as an initiator to form the natural rubber-gra/t-methyl methacrylic acid. Under different conditions, silver ions could be used as a catalyst to produce natural rubber-gra/t-methyl methacrylic acid with different concentrations of methyl methacrylic acid monomers, and potassium peroxydisulfate as an initiator. Consequently, these methods were successful in the preparation of compatible blended natural rubber and methyl methacrylic acid by graft copolymerization. This compatibility was confirmed by nuclear magnetic resonance and infrared spectroscopy techniques. The interaction between natural rubber and methyl methacrylic acid was significantly increased and was useful for further blending with other polyacrylate molecules or different polymer types. 

The Mooney viscosity value of the maleated natural rubbers/poly(methyl methacrylate) blends increased with an increased concentration of maleic anhydride used in the grafting copolymerization. The shear flow property of the... 

Photoreactive Nanomatrix Structures Formed by Graft Copolymerization of 1,9-Nonanediol Dimethacrylate onto Natural Rubber... 

Here, we form the stable inclusion complex of p-CD and NDMA in water under various conditions (Figure 14.1). The resulting inclusion complex was subjected to graft copolymerization onto natural rubber particles with various radical initiators (Figure 14.2). Effects of the amount of inclusion complex and radical initiator on conversion of NDMA are investigated. 

Before graft copolymerization, natural rubber latex was purified to remove most of the protein, which is well known as a radical scavenger to disturb graft polymerization. Figure 14.8 shows H-NMR spectra for DPNR, NDMA and the graft copolymer (DPNR-gr t-poly (NDMA)) prepared from... 

A TEM photograph for DPNR-gra/l-poly(NDMA) is shown in Figure 14. 10, in which a gloomy domain is natural rubber and a bright domain is poly(NDMA). As it is clearly seen, the natural rubber partiele of about 1.0 pm in diameter was dispersed in a poly(NDMA) matrix of 10 mn in thickness to form a nanomatrix structure, while it did not contain poly(NDMA). Furthermore, a volume fraction of poly(NDMA) matrix was estimated by image analysis of the photograph to be about 3 w/w%, which corresponded to 1.81 w/w% estimated from the NDMA content shown in Table 14.2. These results indicate that the graft copolymerization occurs only on the surface of... 

The photoreactive nanomatrix structure was formed by graft copolymerization of the inclusion complex of NDMA with p-CD onto deproteinized natural rubber. The content, conversion and residual methacryloyl group of NDMA for the graft copolymerization were 1.81%, 58.5% and 45.3%, respectively, at NDMA feed of 150 g/kg rubber and initiator concentration of 0.033 mol/kg rubber. The TEM observation of the resulting graft copolymer showed that natural rubber particles of about 1.0 pm in diameter were dispersed in a poly(NDMA) matrix of 10 nm in thickness. 

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