Reaction of Aryl Isocyanates with Cotton Cellulose

Abstract

The thermal dissociations of cellulose N-(2-, 3-, and 4-pyridyl)-carbamates to their respective isocyanates and cellulose were investigated using dynamic and isothermal thermogravimetric analyses. With the aid of a digital computer, kinetic parameters were determined for the dissociation reactions measured by both techniques. First-order kinetics were ob served in every case. Activation energies ranged from 28 to 45 kcal/mole. Entropy of activation values were positive for the 4-isomer and negative for the 2- and 3-isomers. The intermediate postulated for the more thermally labile 4-isomer results from intermolecular catalysis, while those for the 2- and 3-isomers resulted from intramolecular catalvsis.

Keywords

Thermal behavior cotton aryl isocyanates cellulose N-pyridylcarbamates thermogravimetric analysis (TGA).

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References

Franklin, W.E. , Mack, C.H. , and Rowland, S.P. , Reversible Crease Formation in Cotton Cellulose Dicyclopentadiene-dicarboxylate Fabrics, Textile Res. J. 39, 943-949 (1969).

Freeman, E.S. and Carroll, B. , The Application of Thermo-analytical Techniques to Reaction Kinetics. The Thermogravimetric Evaluation of the Kinetics of the Decomposisition of Calcium Oxalate Monohydrate, J. Phys. Chem. 62, 394-397 (1958).

Hobart, S.R. , An Investigation of the Reversibility of N-Methylol-Acrylamide Crosslinks on Cotton, Textile Res. J., 37, 380-390 (1967).

Hobart, S.R. , Berni, R.J. , and Mack, C.H. , Thermal Investigation of Diethylaminoethyl-Substituted Cotton Celluloses, Textile Res. J. 40, 1079-1086 (1970).

Hobart, S.R. and Mack, C.H. , Reaction of Aryl Isocyanates with Cotton Cellulose. Part V: Reaction Via Diphenyl N,N'-Arylene-dicarbamates, Textile Res. J. 39, 317-323 (1969).

Hobart, S.R. and Mack, C.H. , "Thermal Analysis of Phenylcarbamoylated Cotton Cellulose," Eds. R. F. Schwenker , Jr., and P. D. Garn , New York, Academic, 1969, vol. 2, pp. 571-596.

Hobart, S.R. , Mack, C.H. , and Wade, C.P. , The Wrinkle Recovery Properties of Acethydrazide Disulfide-CrossLinked Dialdehyde and Dialcohol Cottons, Textile Res. J. 36, 30-37 (1966).

Hobart, S.R. , McGregor, H.H. , Jr., and Mack , C.H. , Reaction of Aryl Isocyanates with Cotton Cellulose. Part IV: Reaction Via Phenyl N-Arylcarbamates , Textile Res. J. 38, 824-830 (1968).

Hobart, S.R. , McGregor, H.H. , Jr., and Mack, C.H. , Certain Phenyl N-Aryl or N-Heteroalkyl Carbamates and Derivatives Thereof , U. S. 3 584 000 (June 8, 1971).

10.

Mack, C.H. and Donaldson, D.J. , Effects of Bases on the Pyrolysis of Cotton Cellulose, Textile Res. J. 37, 1063-1071 (1967).

11.

Mack, C.H. and Hobart, S.R. , Reaction of Aryl Isocyanates with Cotton Cellulose. Part III. Thermal Behavior of Product, Applied Polymer Symposia No. 2, 133-147 (1966).

12.

Mack, C.H. , McGregor, H.H. , Jr., and Hobart, S.R. , Synthesis of Some Phenyl N-Arylcarbamates, J. Chem. Eng. Data 14, 258-261 (1969).

13.

Rowland, S.P. and Brannan, M.A.F. , Mobile Ester Cross Link for Thermal Creasing of Wrinkle-Resistant Cotton Fabric, Textile Res. J. 38, 634-643 (1968).

14.

Rowland, S.P. and Brannan, M.A.F. , Introduction and Removal of Durable Creases in Wrinkle-Resistant Cotton Fabric, Textile Res. J. 40, 607-613 (1970).

15.

Rowland, S.P. and Brannan, M.A.F. , A Delayed Curing Cotton Fabric Based on an Internally Catalyzed Cotton and Divinyl Sulfone, Textile Res. J. 39, 173-180 (1969).

16.

Schwenker, R.F. , Jr. and Lifland , L. , 6,6'-Disulfide CrossLinks in Cotton Cellulose. Part II: Effects of Different Cross-Linking Conditions , Textile Res. J. 33, 107-117 (1963).

17.

Schwenker, R.F. , Jr., Lifland , L. , and Pascu, E. , 6,6'-Disulfide Cross-Links in Cotton Cellulose; Effects on Fabric Wrinkle Recovery, Textile Res. J. 32, 797-804 (1962).