Butadiene copolymers, extraction

In order to assess the optimal complexity of a model, the RMSEP statistics for a series of different models with different complexity can be compared. In the case of PLS models, it is most common to plot the RMSEP as a function of the number of latent variables in the PLS model. In the styrene—butadiene copolymer example, an external validation set of 7 samples was extracted from the data set, and the remaining 63 samples were used to build a series of PLS models for ris-butadicne with 1 to 10 latent variables. These models were then used to predict the ris-butadicne of the seven samples in the external validation set. Figure 8.19 shows both the calibration fit error (in RMSEE) and the validation prediction error (RMSEP) as a function of the number of... 

Figure 15.7 Results demonstrating that much more polymeric material can be extract by suitable organic solvents bom vulcanizates derived from polystyrene-polybutadie blends than from vulcanizates from styrene-butadiene copolymers (Shundo et al. [19 ( ) peroxide-vulcanized copolymers (O) sulfur-vulcanized copolymers (O) radi don-vulcanized copolymers (A) peroxide-vulcanized latex blends (A) sulfiir-vulcaniz< latex blends (A) radiation-vulcanized latex blends ( ) peroxide-vulcanized roll blenr ( ) sulfur-vulcanized roll blends (Qf) radiation-vulcanized roll blends. The compoun for peroxide vulcanizates and sulfur vulcanizates were as given in the cation Figure 15.6. The compound for radiation vulcanization was (parts by mass) polymer 10 calcium caibonate ICIO. Roll blending was done at 110°C. Peroxide and sulfur vulca-izatkxis were carried out at 150°C. Radiation vulcanization was achieved using 10 n from a cobaIt-60 source in air at normal ambient temperature...

Rubber or butadiene copolymers Dispersion is broken by acidifying as long as soap is used as the emulsifier After acidifying, fatty or resin acid is extractable with ether latex is precipitated... 

IR spectroscopy may be used for detection of plasticisers in soft PVC cables [75], but does not distinguish clearly between the many possible di-alkylphthalates. With the advent of difference spectroscopy, identification of a plasticiser in a polymer no longer requires isolation of the additive. Identification can readily be made without separation if the polymer is known and a plasticiser-free spectrum is available. This was illustrated for di-2-ethylhexylsebacate in an acrylonitrile-butadiene copolymer [76]. IR can sometimes quantify plasticisers in solid plastic compositions without the need for extraction or dissolution steps. FTIR difference spectroscopy has also been used for quantitative analysis. Another example of difference spectroscopy is the case of two plastic films which differed in printability [77]. Difference mid-IR spectra of the surfaces of the two films in the 1600-1300 cm region revealed a stearate (and eventually a free acid, at 1720 cm ). Surface properties of... 

A methanol extract of a weighed portion of the polymer is pyrolysed at 700°C and the pyrolysis products swept on to a gas chromatograph and then determined. For example if a styrene-butadiene copolymer is being examined then determination of 1,3 butadiene in the pyrolysis products enables the bound butadiene content of the copolymer to be determined. The procedure is calibrated against copolymers of known composition, or, alternatively against injections of the pure monomers. 

Bauer et al. describe the use of a noncontact probe coupled by fiber optics to an FT-Raman system to measure the percentage of dry extractibles and styrene monomer in a styrene/butadiene latex emulsion polymerization reaction using PLS models [201]. Elizalde et al. have examined the use of Raman spectroscopy to monitor the emulsion polymerization of n-butyl acrylate with methyl methacrylate under starved, or low monomer [202], and with high soUds-content [203] conditions. In both cases, models could be built to predict multiple properties, including solids content, residual monomer, and cumulative copolymer composition. Another study compared reaction calorimetry and Raman spectroscopy for monitoring n-butyl acrylate/methyl methacrylate and for vinyl acetate/butyl acrylate, under conditions of normal and instantaneous conversion [204], Both techniques performed well for normal conversion conditions and for overall conversion estimate, but Raman spectroscopy was better at estimating free monomer concentration and instantaneous conversion rate. However, the authors also point out that in certain situations, alternative techniques such as calorimetry can be cheaper, faster, and often easier to maintain accurate models for than Raman spectroscopy, hi a subsequent article, Elizalde et al. found that updating calibration models after... 

The original objective in preparing emulsion polymers from the 2,6-dichlorostyrene and acenaphthylene was to obtain polymeric fillers of higher Tg than that of polystyrene. It was also presumed that these fillers would not be bonded chemically to the rubber during vulcanization and that the copolymers with butadiene would enable such bonding to be effected. Actually, the polydichlorostyrene and polyacenaphthylene did become bonded to the rubber, as indicated by the inability to extract most of the filler by solvents. The final result was that the copolymers with butadiene served merely as fillers of lower Tg than the above homo-... 

As shown in Figure 1.17, there are three possible dichloroethylene compounds, all clear, colorless liquids. Vinylidene chloride forms a copolymer with vinyl chloride used in some kinds of coating materials. The geometrically isomeric 1,2-dichloroethylenes are used as organic synthesis intermediates and as solvents. Trichloroethylene is a clear, colorless, nonflammable, volatile liquid. It is an excellent degreasing and dry-cleaning solvent and has been used as a household solvent and for food extraction (for example, in decaffeination of coffee). Colorless, nonflammable liquid tetrachloroethylene has properties and uses similar to those of trichloroethylene. Hexachloro-butadiene, a colorless liquid with an odor somewhat like that of turpentine, is used as a solvent for higher hydrocarbons and elastomers, as a hydraulic fluid, in transformers, and for heat transfer. 

N-Methylpyrrolidone [872-50-4] (NMP) has a fairly mild, amine-like odor, and is miscible with water and most organic solvents. It has a good solvency for cellulose ethers, butadiene-acrylonitrile copolymers, polyamides, polyacrylonitrile, waxes, polyacrylates, vinyl chloride copolymers, and epoxy resins. It is used in paint removers and stripping paints to reduce paint viscosity, and to improve the wettability of paint systems. A -Methylpyrrolidone is also employed for the extraction of hydrocarbons, and as a solvent in the synthesis of acetylene. 

Krameria argentea extract Krameria extract Krameria triandra extract. See Rhatany extract Kraton D 1101] Kraton D 1102. See Styrene/butadiene/styrene block copolymer Kraton D 1107] Kraton D 1107P] Kraton D 1111] Kraton D 1112P. See Styrene/isoprene/styrene block copolymer Kraton D 1116. See Styrene/butadiene polymer... 

Kraton elastomer consists of block segments of styrene and rubber monomers and are available as Kraton D and G series. The D series is based on unsaturated midblock styrene-butadiene-styrene copolymers whereas the G series is based on styrene-ethylene/butylene-styrene copolymers with a stable saturated midblock. Listed among the attributes of both series are such features as low extractables, dimensional stability. 

The morphological structure of the butadiene-acetylene graft copolymer films was studied using TEM, electron diffraction and wide-angle X-ray scattering (WAXS). A series of the butadiene-acetylene copolymers with acetylene content ranging from 10 to 50 wt% and a cisitrans ratio from 70/30 to 10/90 was prepared [73]. Unreacted polybutadiene homopolymer was extracted from the copolymer samples in toluene... 

Polyethylene has also been modified by extrusion at 200°C in the presence of isoprene-styrene rubbers or butadiene-styrene rubbers. The formation of graft copolymers has been shown by solvent extraction tests and IR spectroscopy. Grafts of the first composition are more easily induced by the tertiary proton reactions in the isoprene units. The crack resistance of polyethylene reportedly increases exponentially with the amount of graft content [234]. 

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