Preparation of strongly acidic cation-exchange resins from gymnosperm acid hydrolysis lignin

Abstract

The chemical preparation of strongly acidic cation-exchange resin from sulfuric acid lignin (Klason lignin) (SAL), a typical acid hydrolysis lignin, was investigated. Sulfonation of resinified SAL itself gave a resin with an ion-exchange capacity of 2.3 mEq/g. After resinification with formaldehyde, the phenolized SAL with a reactive phydroxyphenyl group yielded a resin with an ion-exchange capacity of 3.2 mEq/g. The latter capacity is superior to that of the corresponding commercial phenol-type resins (2-3 mEq/g), but did not reach the level of the corresponding commercial styrene-type resins (4-5 mEq/g).

Production and Application of Lignosulfonates and Sulfonated Lignin

“…[98,105] When tetrachloroethane was used as an alternative solventi nt his process,t he sulfur contentwas increased to 14 wt %. [99] Sulfonation withoutr esinification pretreatmenty ielded lower values of sulfur content,degree of sulfonation, and surface chargedensity of 7.8 wt %, 0.60, and 2.3 meq g À1 ,r espectively. In this process, lignin was first reactedwith formaldehyde to form resinified hydrolysis lignin, and subsequently sulfonated with chlorosulfonic acid in the presence of tetrachloroethane.…”

“…[98] In this process, phenolated lignin was treated at 0.875:1 (w/w)c hlorosulfonica cid/lignin in chloroform (0.005 (v/w)t ol ignin) for 1hat 25 8Ca tp H2. [99] The resinified phenolated lignin was filtered prior to dissolution in tetrachloroethane( at 0.02 (v/w)t ol ignin) then reactedw ith chlorosulfonic acid( 2.5 (w/w)r atio to lignin) for 3h at 100 8Ci nN aOH. [98,105] When tetrachloroethane was used as an alternative solventi nt his process,t he sulfur contentwas increased to 14 wt %.…”

“…[98] It was reported that an increase in the reaction temperature from 0t o 25 8Cd uring arylsulfonation of phenolated hydrolysis lignin resulted in an increase in sulfonation (9.0 to 9.5 wt %) andmolecular weight( approximately 9500 to 22 000 gmol À1 ). [99] The product could be filtered and dried for purification.T he sulfur content of the product was 10.2 wt %w ith ad egree of sulfonation of 1.37 groups/C 9 unit and as urfacec harge density of 3.2 meq g À1 . [98,105] In process Do fS cheme 11,f ormaldehyde treatment of phenolatedh ydrolysis lignin prior to sulfonation is outlined.…”

“…[98,105] In process Do fS cheme 11,f ormaldehyde treatment of phenolatedh ydrolysis lignin prior to sulfonation is outlined. [99] Resinification pretreatment allowed for improved properties compared with those of the unsulfonated sample, and thus, the sulfonated products was proposed for use as ion-exchanger esins. One study reported phenolated lignin wasr eacteda t1 :0.005 (v/w) ratio with formaldehydef or 2hat 180 8Cu nder alkaline conditions.…”

“…In this process, lignin was first reactedwith formaldehyde to form resinified hydrolysis lignin, and subsequently sulfonated with chlorosulfonic acid in the presence of tetrachloroethane. [99] 3.11. [99] The resinified phenolated lignin was filtered prior to dissolution in tetrachloroethane( at 0.02 (v/w)t ol ignin) then reactedw ith chlorosulfonic acid( 2.5 (w/w)r atio to lignin) for 3h at 100 8Ci nN aOH.…”