MAGNETIC-FIELD PROCESSING OF POLYMERS .1. HYDROXYPROPYL CELLULOSE

Hydroxypropyl cellulose (HPC) of degree of substitution three and average molecular weight of 100,000 was processed in a magnetic field of 1.2 T. Films of HPC were cast from water, methanol, ethyl methyl ketone, and 1,1,2,2-tetrachloroethane solutions in a magnetic field using static and dynamic casting techniques. The processed films were evaluated for tensile strength, elastic modulus, microhardness, and molecular chain alignment by wide angle x-ray diffraction and polarized infrared. The best alignment and hence the greatest improvement in properties was obtained using a combined magnetic field and flow alignment procedure. These samples showed no increase in the elastic modulus, a 106% increase in the tensile strength, a 21% increase in the microhardness, and were dichroic. (C) 1994 John Wiley & Sons, Inc.(double dagger)