Insolubility, lignin in wood

Colombo P, Corbetta D, Pirotta A, Ruffini G (1962) Chlorine number as a method for evaluation of lignin content of a pulp Pulp Pap Mag Can 63 T126-T140 Effland MJ (1977) Modified procedure to determine acid insoluble lignin in wood and pulp Tappi 60(10) 143-144... 

Tasman JE (1959) The permanganate consumption of pulp materials. IV. The kappa correction coefficient. Pulp Pap Mog Can 60(No. C) 231-235 Technical Association of the Pulp and Paper Industry, Atlanta, (1983) Acid-insoluble lignin in wood and pulp. Official Test Method T-222 om-8 Technical Association of the Pulp and Paper Industry, Atlanta, (1985a) Micro kappa number. Useful Method UM 246... 

Lignin content ASTMDl 106-96 Standard Test Method for Acid Insoluble Lignin in Wood Corn husk, banana bunch 7,20,25... 

Solution Properties. Lignin in wood behaves as an insoluble, three-dimensional network. Isolated lignins (milled wood, kraft, or organosolv lignins) exhibit maximum solubiUty in solvents having a Hildebrand s solubiUty parameter, 5, of 20.5 — 22.5(J/cm ) (10 — ll(cal/cm ) > and A// in excess of 0.14 micrometer where A]1 is the infrared shift in the O—D bond when the solvents are mixed with CH OD. Solvents meeting these requirements include dioxane, acetone, methyl ceUosolve, pyridine, and dimethyl sulfoxide. 

Determination of Acid-Insoluble (Klason) Lignin in Wood and Pulp... 

Solution Properties. Lignin in wood behaves as an insoluble, three-... 

Alkaline-extracted/acid hydrolysis (AH/NaOH) lignin samples were prepared by subjecting aspen wood flour to a one hour cook at 120°C in 0.05N sulfuric acid (22), followed by mixing the clarified supernatant with 1% w/w NaOH at 25°C with a Waring blender. The insoluble lignins were precipitated by addition of acid and water washes (32% yield). 

Note 5. Insolubles are present when Klason lignin or wood meal is used. After a 40-min ozonation of wood meal, examination of the insoluble residue (in KBr) by FTIR showed the absence of characteristic lignin absorption bands. 

In this study, the lignin content [X] In wood has been replaced by Klason lignin contents of the residues. It should be noted that Klason lignin only accounts for the acid-insoluble portion of the lignin In the wood residue and therefore represents the lower limit of the lignin that actually exist In the wood residue. The amount of soluble lignins that may remain In the residue has not been further Investigated In this study. 

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