Methods for Biodegradable Derivatization of Cellulosic Surfaces

Abstract

The present invention describes methods of treating cellulosic materials with a composition that provides increased hydrophobicity to such materials without sacrificing the biodegradability thereof. The methods as disclosed provide for esterification of available hydroxyl groups on cellulosic materials, where such hydroxyl groups are “masked” by bulky organic chains, including that the disclosure provides products made by such methods. The materials thus treated display higher hydrophobicity, barrier function, and mechanical properties, and may be used in any application where such features are desired.

1 . (canceled) 
     
     
         2 . The cellulosic product of  claim 14 , wherein said surface comprises greater hydrophobicity relative to a surface without said compound. 
     
     
         3 .- 6 . (canceled) 
     
     
         7 . The cellulosic product of  claim 14 , comprising nanocellulose, cellulose nanofibres, whiskers or microfibril, microfibrillated or nanofibril cellulose, sugarcane cellulose, cotton or cotton blends or combinations thereof. 
     
     
         8 . (canceled) 
     
     
         9 . The cellulosic product of  claim 14 , wherein said compound is
 selected from the group consisting of acid chlorides, acid bromides, acid iodides, anhydrides, ketenes, diketenes, chlorocarbolic acid esters, carbonic acid diesters, 2,5-diketooxazolidines, isatinic anhydride, isocyanates, carbamoyl chlorides, thiocyanates, thiocarbamoyl chlorides, sulfonyl chlorides, sulfonic acid anhydrides, N-chlorosulfonamides, sulfinic acid chlorides, N-chlorosulfinamides, and combinations thereof.   
     
     
         10 .- 13 . (canceled) 
     
     
         14 . A solid cellulosic product, wherein a surface thereof comprises hydroxyl groups in ester linkage with a compound having the formula (I):
   R—CO—X
   
       wherein R is a straight-chain, branched-chain, or cyclic aliphatic hydrocarbon radical having from 6 to 50 carbon atoms, and wherein X is Cl, Br, or O(CO)OR and, said sample comprises a water contact angle of between about 60° to about 120°. 
     
     
         15 . The product of  claim 14 , where said compound in ester linkage is chemically stable up to temperatures of between about 200° C. to about 250° C. 
     
     
         16 . The product of  claim 14  wherein water vapour permeability of said surface is between about 10 Barrer units to about 20 Barrer units. 
     
     
         17 . The product of  claim 14 , wherein oxygen permeability of said surface is between about 10 Barrer units to about 20 Barrer units. 
     
     
         18 . The product of  claim 14 , wherein the product is biodegradable. 
     
     
         19 . The product of  claim 14 , wherein the product is selected from the group consisting of a carton for food storage, a bag for food storage, a bottle for carbonated liquid storage, a bottle for non-carbonated liquid storage, film for wrapping food, a garbage disposal container, a food handling implement, a fabric fibre, a water storage and conveying implement, alcoholic or non alcoholic drinks, an outer casing or screen for electronic goods, an internal or external piece of furniture, a curtain, upholstery and combinations thereof. 
     
     
         20 . (canceled)