Abstract
The effect of introducing chelate ring into resin structure on thermal stability was studied. Thermal stability is expected to change by the position of chelate ring introduced in polymers. Tyrosin having both phenolic OH group and chelate forming groups (NH2 and COOH) is considered to be copolymerized with phenol to give a condensation products. Thermal analysis was done for the following compounds; Amberlite IRC 50 and its copper salt, tyrosin and tyrosin copper chelate, tyrosin-phenol condensation product and its chelated products which were treated with CuCl2 solution at pH 2. 0, 3. 0, and 3. 6 respectively, tyrosin copper chelate-phenol condensation products of various tyrosin copper chelate content, and phenol resin. Weight loss vs temperature curves of those compounds show that ion exchange resin of COOH type shows nearly the same thermal stability as that of COO Cu/2 type resin. Tyrosin copper chelate has a lower decomposing temperature than tyrosin, but it shows the better thermal stability in the higher temperature range. Among the tyrosin-phenol resins, chelated resins show much better stability than nonchelated, and the more chelate rings are formed, the higher their stabilities. Thermal properties of tyrosin copper chelate-phenol resin change with the content of chelate ring. These stability differences are explained on the bases of the following assumptions. The chelate ring in the part of side chain of repeating units of resin gives additional stability to the non-chelated resin of the same composition. Chelate ring has a rigid structure of a definite bond angle and distance, therefore introducing these rings into resin as one of repeating units will give some effects on the steric structure of the whole resin and strain may occure in it.
The effects of promoting thermal stability by introducing chelate ring is cancelled by increasing the strain in resin.
