Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Lignosulfonates molecular weight

Sacrificial adsorption agents such as lignosulfonates (148—151) can be used to reduce the adsorption of more expensive polymers and surfactants. Other chemicals tested include poly(vinyl alcohol) (152), sulfonated poly(vinyl alcohol) (153), sulfonatedpoly(vinylpyrrohdinone) (153), low molecular weight polyacrylates (154), and sodium carbonate (155). [Pg.193]

Modem concretes often incorporate a mixture of chemical and mineral admixtures, each of which may interact with the various constituents of cements and influence cement hydration reactions. The admixture-cement interactions may in fact be viewed as the reaction between two complex chemical systems - the multicomponent, multiphasic inorganic materials in the cement and the organic compounds of multicomponent admixture systems. For example, lignosulfonate water-reducers are intrinsically complex mixtures of chemical compounds derived from the chemical degradation of lignin, while synthetic admixtures such as superplasticizers contain species with a broad distribution of molecular weights, reaction products, or other chemicals added for a specific purpose [125]. The performance of an admixture in concrete is highly dependent on many... [Pg.520]

Figure 1.5 is a typical molecular weight distribution curve for a lignosulfonate obtained by means of gel permeation chromatography (a sophisticated analytical method where molecules are sieved according to their molecular size). [Pg.22]

Figure 10. Effect of peroxide charge on copolymerization of lignosulfonate and methyl methacrylate. Conditions water medium 50°C 120 min reaction time. Key , total monomer conversion A, degree of LS reacted O, grafting efficiency , molecular weight of MMA homopolymer. Figure 10. Effect of peroxide charge on copolymerization of lignosulfonate and methyl methacrylate. Conditions water medium 50°C 120 min reaction time. Key , total monomer conversion A, degree of LS reacted O, grafting efficiency , molecular weight of MMA homopolymer.
Subsequently, propane side chains and hydrogen ions are eliminated, respectively. In general, the condensation reactions result in increased molecular weight of the lignosulfonates and the solubilization of lignin is... [Pg.113]

Another category of lignin-based chemicals is obtained when lignosulfonates are degraded to low molecular weight products. The commercially most important product is vanillin, which is obtained by alkaline oxidation... [Pg.198]

Yean WO, Goring DAI (1965) The molecular weight of lignosulfonates from morphologically different subdivisions of wood structure. Sven Papperstidn 68 787- 790 Yoshihara K, Kobayashi T, Fujii T, Akamatsu I (1984) A novel modification of Klason lignin quantitative method. J Jpn Tappi 38(4) 86-95... [Pg.61]

See other pages where Lignosulfonates molecular weight is mentioned: [Pg.142]    [Pg.144]    [Pg.145]    [Pg.180]    [Pg.180]    [Pg.182]    [Pg.194]    [Pg.194]    [Pg.83]    [Pg.378]    [Pg.38]    [Pg.42]    [Pg.178]    [Pg.149]    [Pg.32]    [Pg.32]    [Pg.33]    [Pg.450]    [Pg.529]    [Pg.12]    [Pg.253]    [Pg.319]    [Pg.524]    [Pg.82]    [Pg.83]    [Pg.49]    [Pg.17]    [Pg.22]    [Pg.22]    [Pg.23]    [Pg.338]    [Pg.408]    [Pg.293]    [Pg.296]    [Pg.298]    [Pg.198]    [Pg.203]    [Pg.8]    [Pg.9]    [Pg.78]   
See also in sourсe #XX -- [ Pg.7 ]



SEARCH



Lignosulfonate

Lignosulfonates

© 2024 chempedia.info