Liquid epoxidized natural rubber

Among the polymer electrolytes obtained from natural polymers, Klink-lai et reported ionic conductivity and NMR spectroscopy of polymer electrolytes formed by the mixture of liquid epoxidized natural rubber with Uthium salts. The authors discussed the correlation between the spin-lattice relaxation times with the solubility of the different lithium salts in the deprotonized liquid rubber. Based on the NMR chemical shift and the resonance half-width and the spin-lattice relaxation times results they concluded that lithium bis(trifiuoro methane sulfonyl)imide is a suitable salt for forming polymer electrolytes with deprotonized liquid natural rubber. 

As natural rubber is a product of nature, its properties are determined by the biochemical pathway by which the polymer is synthesized in the plant. In the case of natural rubber the polymerization process cannot be tailored like that of synthetic rubbers. The only option to modify natural rubber is after it has been harvested from the tree. The important modified forms of natural rubber include hydrogenated natural rubber, chlorinated natural rubber, hydro-halogenated natural rubber, cyclized natural rubber, depolymerised liquid natural rubber, resin modified natural rubber, poly(methyl methacrylate) grafted natural rubber, poly(styrene) grafted natural rubber, and epoxidized natural rubber [33,34]. Thermoplastic natural rubber prepared by blending natural rubber and PP is considered as a physically modified form of natural rubber. 

The third category of natural rubbers are the specialty materials, which include liquid low molecular weight rubber, methyl methacrylate grafted polymers, oil-extended natural rubber, deproteinized natural rubber, epoxidized natural rubber, and superior-processing natural rubber. 

Natural rubber/chlorosulfonated polyethylene rubber blends also exhibited immiscibility. Chlorosulfonated polyethylene rubber is the synthetic rubber used for applications in electric cables, hoses for liquid chemicals, waterproof cloths, floor tiles, and oil-resistant seals. It is chosen to blend with natural rubber to improve the resistance of natural rubber to ozone, oil, heat, flame and non-polar chemicals. This is due to the effect of the polarity of the chlorine groups in the chlorosulfonated polyethylene rubber. The tensile strength, elongation at break, and tear strength of these blends decreased with the increasing chlorosulfonated polyethylene rubber contents. In addition, the compatible natural rubber/chlorosulfonated polyethylene rubber blends were improved by adding the epoxidized natural rubber (Epoxyprene 25) as a... 

In addition, polymers with free carboxylic acid groups such as PAA and poly(methacrylic acid) can form copolymer electrolytes with PEO, leading to a sharp increase in ionic conductivity. Apparently, the PAA or other polycarboxylic acids can increase the lithium-ion transference number by decreasing the transfer of anions. The ionic conductivities of these copolymer electrolytes can be further increased by adding boron trifluoride diethyl etherate (Bp30Et2), which can promote the dissolution of lithium cations and carboxylic acid anions. Epoxidized natural rubber can also increase the ionic conductivity of PEO. Addition of symmetric poly(styrene-Wocfc-ethylene oxide) copolymers obviously affects the distribution of Lb ions. In contrast to current solid and liquid electrolytes, its ionic conductivity increases with increasing molecular weight of the copolymers. 

Materials. The epoxidation of liquid natural rubber (M = 8000) was carried out by mixing a chloroform solution of the polymer and an acetic acid solution of peracetic... 

Fig.2 Influence of the epoxy content on the photoinitiated cationic polymerization of epoxidized liquid natural rubber (ELNR). ( ) Photolysis of the photoinitiator ( A) [TAS] = 3 wt %.

The ring opening reaction of naphthyl acetic acid with epoxidized liquid natural rubber (ELNR) (Fig. 33) under microwave irradiation was studied by Huy et al. [125]. The reactions were carried out in a chlorobenzene solution (1.2 ml) in a... 

Fig.33. Fixation of a-naphthyl acetic acid (NAA) onto epoxidized liquid natural rubber. Reprinted from (1996) J Mater Sci Pure Appl Chem A33 1957 [125] with permission...

It has been proved that the nature of solvent used for casting in the preparation of the blend influences the compatibility and related properties of PS-poly(vinyl methyl ether) (PVME) mixtures." Clear films of PS-PVME mixtures were obtained on casting from solvents like benzene, toluene, etc., while visually incompatible films result upon casting from trichloroethylene and chloroform. Blends of PVC and LNR/epoxidized liquid natural rubber (ELNR) were prepared using a common solvent, 2-butanone. ° Another research group prepared PVC/NR blends using THE as the solvent. ... 

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