lihn ctl SrondrF19un 3. Changms In vlrcoslty with Increose ond decrees. in tmmpwotum In a PVM/MA-HA dispwslon prepared at 17OoF. t h i s point the solution became slightly more turbid and assumed a n amber color (5).No appreciable change in viscosity w a s observed when PVM/MA copolymer solutions were heated a t different temperatures for varying periods of time (5). Thus, if the decrease in viscosity, observed in the case of solutions of t h e half amide, is due t o oxidative degradation, it is poss i b l e that t h e reactivity of t h e tertiary hydrogen atoms is governed in part by t h e nature of the carboxylate groups.T h e replacement of carboxyl hydrogens with t h e amide and/or ammonium groups may favor t h e formation of hydroperoxides, which in turn readily decompose to bring about chain scission.Unfortunately, no attempt w a s made to investigate the fundamental a s p e c t s of t h e observed viscosity behavior. However, t h e experiments reported were helpful in devising methods for t h e preparation of improved lithographic plate coating solutions. ACK NOWL EQGYENTT h e author wishes t o express h i s appreciation to F. Trusheirn and L. R. Wickland for their interest and c o o p e r e tion in t h i s work and to W. W. Rinne for h i s suggestions in the preparation of the manuscript. Acknowledgment is also made t o t h e Corps of Engineers, U. S. Army, Anny Map Service, for permission to publish t h e r e s u l t s of this work. LITERATURE CITED (1) Cletc, L P., "Ilford Yanud of P m c e m Work," p 237, Word (2) General Anlllne L Fllrn Cop., New Product Bull. P-103 (JM.