Cellulose ether prods. with high degree of polymerisation - prepd. by etherifying raw cotton linters with alkyl halide and opt. alkylene oxide, useful thickening agents

摘要

Cellulose ethers (I) are prepd by (1) reacting 100 pts (all pts wt) dry war linters with 60-190 pts alkyl halide (II) in presence of 50-150 pts alkali to etherify cellulose in the linters (2) washing etherified raw linters with hot water and drying. Linters are etherified With mixt to 60-90 pts. (II) and up to 100 pts alkylene oxide (III). (II) is MeCl at EtCl. (III) is ethylene oxide or propylene oxide. USE/ADVANTAGE - Thickening agent, partic as additive to cement-based hydraulic mortars or concrete compsns, esp for extrusion or injection casting of preformed objects without use of asbestos as reinforcement. (I), obtd using linters instead of refined linter pulp, have high degree of polymerisation, prime cost is reduced, aq soln ahs very high viscosity (min 20,000 cPs for 1% soln at 20 deg C), less additive is required.