Phosphoric acid infrared spectra

The same membranous material as mentioned in 1) having a thickness of 100 jjl was set in a reactor of the design which would allow only one surface of the membrane to contact with reaction reagents. Thereafter, the reactor compartment was filled with vapour of phosphorous pentachloride ( at 170°C for an hour ) to have one surface of the membrane reacted. The reflective infrared spectrum and dyeing test respectively showed that the membrane had sulfonyl chloride groups and that approximately 5 JJL of non-dyed layer was stratified at the membrane surface where phosphorous pentachloride had contacted. The electric resistance of this membrane was about 1500 ft- cm2 in a 1.0 N hydrochloric acid solution at 25°C when measured by 1000 cycle A.C. The electric resistance of the same membrane before the reaction with phosphorous pentachloride was only 0.38ft - cm2 under the same conditions. 

On the other hand, the electric resistance of the membrane before the reaction with phosphorous pentachloride and triethylamine was 1,1 - cm2 and l,0i2- cm2 respectively when measured in the environment of 3,5 N sodium chloride solution to its one side and 6.0 N sodium hydroxide solution to the other side, and in the environment of 3.5 N sodium chloride solution of pH 0,5, According to reflective infrared spectrum, the absorption bands observed were different between the surfaces reacted with phosphorous pentachloride and non-reacted. Namely the absorption band at 1680cm 1 corresponding to carboxyl groups was observed, and the absorption band at 1060cm l observed in the sulfonic acid type membrane disappeared on the surface which had been reacted with phosphorous pentachloride. 

A new, crystalline modification termed cellulose-x has been reported. It is obtained by treating cotton or wood pulp with concentrated hydrochloric acid at room temperature, or, in a particularly pure form, by the use of phosphoric acid at 50°. A definite interpretation of the structure cannot be given at present, but x-ray results indicate that a unit cell having the same dimensions as that of the high-temperature form of cellulose [cellulose IV (unit-cell dimensions a = 8.12, 6 = 10.3, c = 7.99 A. /8 = 90°) 2 is the most probable one, but having the pyranose rings of the central chain displaced by half a D-glucose residue with respect to the corner chains. The infrared spectrum lies between those of cellulose II and cellulose IV. 

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