Dielectric Properties of Cellulose-acetate Plastics

Dielectric properties of cellulose-triacetate, cellulose (2.4) acetate and cellulose (2.4) acetate plasticized with tributyl phosphate were measured over the wide frequency and temperature ranges, using a mutual inductance bridge and Q-meter. For the unplasticized cellulose-triacetate, single broad loss curve was observed. The activation energy was estimated to be about 15 kcal/mol. For the unplasticized cellulose (2.4) acetate, the absorption curve was characterized by the broad and asymmetrical shape. On the assumption of the overlapping of the two absorption curves, the acitavation energies were calculated as 15 kcal/mol and 13 kcal/mol for the absorptions at high and low temprature regions respectively. These absorptions are reasonable considered to be related to the movement of the side chains, because the observed activation energies are too small for the segmental motion of the main chains. For the sample containing 20% T. B. P., the observed absorption curve was similar to that of the unplasticized cellulose (2.4) acetate. The sample containig 31% T. B. P., gave relatively simple absorption curve. The activation energy was about 14 kcal/ma The cause of this absorption is also assumed as the movement of the side chains.