Carboxylated natural rubber

Natural rubber, low molecular carboxylated Natural rubber, low molecular, amine end groups Hycar Hycar BF Goodrich BF Goodrich 1 Reaction with other functional groups in J polymer... 

Other polymers used in the PSA industry include synthetic polyisoprenes and polybutadienes, styrene-butadiene rubbers, butadiene-acrylonitrile rubbers, polychloroprenes, and some polyisobutylenes. With the exception of pure polyisobutylenes, these polymer backbones retain some unsaturation, which makes them susceptible to oxidation and UV degradation. The rubbers require compounding with tackifiers and, if desired, plasticizers or oils to make them tacky. To improve performance and to make them more processible, diene-based polymers are typically compounded with additional stabilizers, chemical crosslinkers, and solvents for coating. Emulsion polymerized styrene butadiene rubbers (SBRs) are a common basis for PSA formulation [121]. The tackified SBR PSAs show improved cohesive strength as the Mooney viscosity and percent bound styrene in the rubber increases. The peel performance typically is best with 24—40% bound styrene in the rubber. To increase adhesion to polar surfaces, carboxylated SBRs have been used for PSA formulation. Blends of SBR and natural rubber are commonly used to improve long-term stability of the adhesives. 

ATBN - amine terminated nitrile rubber X - Flory Huggins interaction parameter CPE - carboxylated polyethylene d - width at half height of the copolymer profile given by Kuhn statistical segment length DMAE - dimethyl amino ethanol r - interfacial tension reduction d - particle size reduction DSC - differential scanning calorimetry EMA - ethylene methyl acrylate copolymer ENR - epoxidized natural rubber EOR - ethylene olefin rubber EPDM - ethylene propylene diene monomer EPM - ethylene propylene monomer rubber EPR - ethylene propylene rubber EPR-g-SA - succinic anhydride grafted ethylene propylene rubber... 

Fig. 107.—Tensile strengths of natural rubber plotted against the degree of cross-linking with bis-azo vulcanizing agent (O), expressed as equivalent percent (pXlOO). Upper curve ( ) sample prepared using one equivalent percent of bis-azo compound plus monoreactive ethyl azodi-carboxylate for the total degrees of modification of the units indicated on the ordinate scale. (Flory, Rabjohn, and Shaffer.

Figure 3. Effect of various straight-chain potassium C18 carboxylate soaps upon mechanical stability of natural rubber latex (2) (KCt8) potassium stearate (KC18) potassium oleate (KC18") potassium elaidate (KC18Z) potassium linoleate (KC=ZZ) potassium linolenate (KC1H12(oli)) potassium 12-hydroxy stearate ...

It is important to point out that our investigation of counterion effects in carboxylate soaps has so far been concerned almost exclusively with laurate soaps. Laurate soaps were chosen partly because they are generally convenient to handle in that many of them are readily soluble in water to give solutions of low viscosity, and partly because, as has been shown above, laurate soaps are very effective in enhancing the mechanical and chemical stability of natural rubber latex. It must therefore be borne in mind that the conclusions which have been drawn from this investigation concerning effects attributable to counterion variation in laurate soaps may not be generally valid for carboxylate soaps as a family. 

The latexes upon which this industry developed were natural rubber and polychloroprene for solvent resistance. However, technology is advancing to permit penetration of carboxylated nitrile latex for optimized solvent resistance and tougher abrasion resistance. Among the competition to latexes in this field are poly(vinyl chloride) plastisols. As technology develops in producing small particle size latexes from polymers whose synthesis is loo water-sensitive for emulsion polymerization, the dipped goods industry will quickly convert to their utilization from the solvent-based cements of these polymers now employed Prime candidates include butyl rubber, EPDM, hypalon, and vlton. 

In this chapter, some of these uses are explored in greater detail. Goodyear and Hancock in 1847 discovered that, when natural rubber was heated with a small amount of sulfur, the physical properties of the resultant rubber were improved the material became tougher and more resistant to changes in temperature. This process of vulcanisation is also useful for the treatment of synthetic rubbers, and as well as sulfur, many sulfur donors such as symmetrical diphenylthiourea, tetraalkylthiuram disulfides (1) and 2-mercaptobenzothia-zole (2) (Figure 1) can be used.1 These compounds act as accelerators of the process of polymerisation of the diene monomers in synthetic rubbers for this purpose, the additional presence of zinc oxide and preferably a carboxylic acid, e.g. stearic acid, is required. 

Struktol Activator 73. [Struktol] Mixture of zinc salts of aliphatic a aromatic carboxylic acids vulcanization activator for natural rubber. 

Stephen, R., Ranganathaiah, C., Varghese, S., Joseph, K., and Thomas, S., Gas transport through nano and micro composites of natural rubber (NR) and their blends with carboxylated styrene butadiene rubber (XSBR) latex membranes. Polymer, XI, 858-870 (2006). 

The strain recovery curves for (a) XPCL-1.2k/ENR, (b) XPCL-2.0k/ENR, and (c) XPCL-3.6k/ ENR blends. (Reproduced from Chang, Y.-W., Eom, J.-P, Kim, J.-G., Kim, H.-T, and Kim, D.-K. 2010. Preparation and characterization of shape memory polymer networks based on carboxylated telechelic poly( -caprolactone)/epoxidized natural rubber blends. Journal of Industrial and Engineering Chemistry 16 256-260 with permission from Elsevier.)... 

A linear-chained epoxy resin was formulated from phenyl glycidyl ether and nadic methyl anhydride, catalysed by benzyldimethylamine (248). An IR fibre-optic probe was used to follow the conversion of a thermosetting tetrafunctional epoxy resin in which the hardener was an aromatic diamine and a carboxylic dianhydride. A polymerisation system consisting of a cycloaliphatic diepoxide, epoxidised natural rubber (ENR), glycidyl methacrylate (GMA) and a cationic photoinitiator, triphenylsulfonium hexafluoro-antimonate, was studied (75). Multifunctional epoxy/ amine formulations (Epon 825 plus 4,4 -methylene-... 

Yang and co-workers [9,10] used high resolution Py-GC-MS and Fourier transform infrared spectrometry to study the structures of the chlorinated natural rubbers (CNR) prepared by two different processes. The results indicate that the fine structures of CNR prepared from latex and solution processes are different, whereas their basic structures are similar. The molecule of CNR from the latex process contains a few carboxyl and carbonyl groups. The rings on CNR molecular chains should be hexatomic rings. The optimum pyrolytic temperature for CNR is 445 °C, with an available range from 386-590 C. The characteristic pyrolytic products are cyclohexane homologues. 

Waterborne dispersed polymers include both synthetic polymer dispersions and natural rubber. Synthetic polymer dispersions are produced by emulsion polymerization. A substantial part of the synthetic polymer dispersions is commercialized as dry products these include SBR for tires, nitrile rubbers, about 10% of the total PVC production, 75% of the total ABS and redispersable powders for construction materials. Carboxylated styrene-butadiene copolymers, acrylic and styrene-acrylic latexes and vinyl acetate homopolymer and copolymers are the main polymer classes commercialized as dispersions. The main markets for these dispersions are paints and coatings, paper coating, adhesives and carpet backing. 

Cellulose acetate natural rubber (latex), polyisobutylene rubber, neoprene rubber, polyvinyl acetate, ethylene vinyl acetate, polyacrylate (carboxylic), cyanoacrylate, polyamide (versamid), phenoxy, polyester + isocyanate, nitrile-phenolic, polyurethane, and resorcinol-formaldehyde. 

Lopattananon et al. (2007) have prepared blends of maleated natural rubber and carboxylated nitrile rubber in the presence of zinc acetate to form a compatibilizing copolymer through ionic cross-links. The effect of different maleation levels was studied. Blend properties were compared to those for blends with unfunctionalized rubbers. 

Ethylene, chlorosulfonated Natural rubber, epoxidized Nitrile rubber, carboxylated Single Eg I had 35 % Cl and 1 % S (Hypalon O) II was 50 mol % epoxidized El was Kiynac-211 Roychoudhuiy et al. (1992)... 

AFM, atomic force microscopy DMA, dynamic mechanical analysis DSC, differential scanning calorimetry flVR, oxidized natural rubber FTIR, Fourier transform infrared spectroscopy NR, natural rubber PLA, poly(lactic acid) QP, quaternary phosphonium salt TGA, thermogravimetric anal is TPU, thermoplastic polyurethane XPCL, end-carboxylated teledielic... 

R. Stephen, K. Joseph, Z. Oommen, S. Thomas, Molecular transport of aromatic solvents through microcomposites of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends. Composites Science and Technology, ISSN 0266-3538 67 (6) (May 2007) 1187-1194. http //dx.doi.Org/10.1016/j.compscitech.2006.05.009. 

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