Synthesis of Novel Polyaryl(ether–ketones) with tert-Butyl Pendent Groups MIKHAIL G. ZOLOTUKHIN, 1 JAVIER DE ABAJO, 2 JULIO C. ALVAREZ, 2 JOSE G. DE LA CAMPA, 2 DANIEL R. RUEDA 1 1 Instituto de Estructura de la Materia, CSIC, Serrano, 119, 28006, Madrid, Spain 2 Instituto de Ciencia y Tecnologı B a de Polı B meros, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain Received 14 April 1997; accepted 12 November 1997 ABSTRACT: Linear polyaryl ( ether ketones ) containing tert-butyl pendent groups were prepared from aromatic hydrocarbons and aromatic diacid chlorides, both classes of monomers containing tert-butyl pendent groups. The polymers were prepared in high yield and high molecular weight by low-temperature precipitation polycondensation in 1,2-dichloroethane. The presence of meta-oriented moieties and bulky pendent groups played a beneficial role with regard to solubility, while the thermal transitions and thermal resistance were not greatly impaired relative to conventional all para-oriented polyaryl ( ether – ketones ) . The current polyaryl ( ether – ketones ) showed glass transi- tion temperatures in the range 170–240°C and decomposition temperatures, as mea- sured by TGA, of about 500°C.  1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1251–1256, 1998 Keywords: ether ketones; synthesis; NMR; thermal properties INTRODUCTION polyamides. 5–8 Polyketones containing side alkyl groups have also been described by a number of authors. 9–17 Apart from improved processability, Aromatic poly ( ether – ketones ) are a class of poly- mers that have gained technical interest because polyketones containing alkyl groups have been characterized as highly sensitive, negative resist they have outstanding thermal and mechanical properties. 1,2 As with most high-performance materials. 10 tert-Butyl groups have been intro- duced into aromatic polyamides, and their pres- polymers, high molecular order and structural ri- gidity are responsible for the desirable features of ence as side substituents has greatly improved the solubility of these semirigid polymers without these special polymers, but these elements ac- count also for the remarkable intractability of substantial diminution of thermal properties. 6,7 The purpose of this work has been to prepare many of them. Molecular order can be disrupted by the incor- novel polyaryl ( ether – ketones ) with improved processability by making use of meta-oriented poration of meta-oriented linkages and by the presence of bulky side substituents. In fact, there monomers and monomers containing tert-butyl pendent groups. Spectral data, solubility, and are many recent examples of how these general approaches have permitted improvement in the thermal properties have been determined and are discussed in relationship to chemical structure. solubility of aromatic polyimides, 3 polyesters, 4 or EXPERIMENTAL Dedicated to Prof. F. J. Balta ´ Calleja on the occasion of his 60th birthday. Materials Correspondence to: J. de Abajo Isophthaloyl chloride and diphenyl ether were pu- Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 36, 1251 – 1256 ( 1998 )  1998 John Wiley & Sons, Inc. CCC 0887-624X/98 / 081251-06 rified by vacuum distillation before use. 5-tert-Bu- 1251 97064T / 8g6c$$064t 03-19-98 13:55:42 polca W: Poly Chem