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Polycondensation of several aliphatic and fluorine-containing, aromatic diamines with two isomeric aromatic diketones has been accomplished by means of acid-catalyzed solution polymerizations. The three polymeric products were semiaromatic or completely aromatic depending upon the diketone-diamine combination employed. Comparative thermal stabilities of the products both in air and in an inert atmosphere were investigated by thermogravimetric analysis. The completely aromatic, fluorine-containing polymers exhibited a high degree of thermal stability and all three of the polymers synthesized exhibited the surprising property of essentially the same resistance to initial thermal decomposition in the oxidative as well as the inert atmosphere. Three isomeric polymers synthesized in a previous investigation by the acid-catalyzed polycondensation of mdibenzoylbenzene with the three phenylenediamines were subjected to thermogravimetric analysis after which the condensable volatiles were collected and then analyzed by combined vapor phase chromatography and mass spectroscopy. Separation and identification of the products given off upon thermal degradation by this combined analytical technique has indicated that different mechanisms are operative in the thermal decomposition of these isomeric polymers. PolymericSchiff bases synthesized from dialdehydes and aromatic diamines have been reported by several investigators to exhibit a high resistance to thermal stress.2-5 However, there are very few examples reported in the literature in which a diketone is used as the starting dicarbonyl.6,7 We have, therefore, undertaken to synthesize and characterize the thermal behavior of a series of polymers based upon the condensation polymerization of various aliphatic and aromatic diamines with several isomeric aromatic diketones. The polymers obtained varied in molecular structure since their backbones ranged from semiaromatic to completely aromatic depending upon the starting diketone-diamine combination employed.Three polymers were synthesized by the acid-catalyzed polycondensation of w-dibenzoylbenzene with ethylenediamine, and by the polycondensation of /7-dibenzoylbenzene with tetrafluoro-m-phenylenediamine and tetrafluoro-p-phenylenediamine. The thermal stability of these polymers was determined by thermogravimetric analysis in air and in an inert atmosphere. In addition, three isomeric polymers which were synthesized in a previous investigation8 by the polycondensation of 7?7-dibenzoylbenzene with o-, m-, and /7-phenylenediamine were subjected to combined thermogravimetric analysis (tga)-vapor phase chromatography (vpc)mass spectral analysis (ms). By means of this combined analysis, it was possible to degrade thermally a polymer (1) To whom correspondence should be addressed.(2) A.

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Polymer blends of ethylene-propylene elastomers and polypropylene plastics, referred to as thermoplastic olefins, are finding increasing use in automotive applications. The combination of attractive mechanical properties, low raw material cost and recyclability make these materials ideal substitutes for expensive engineering thermoplastics (polycarbonate/polybutylene terephthalate alloys) and nonrecyclable polyurethane systems. The primary application is in automotive bumper fascia. This paper describes the addition of long chain branched ethylene-propylene elastomers in thermoplastic olefin compounds containing a high flow polypropylene resin matrix. In such compounds, the modifier molecular architecture plays an important role in impact toughening. The results clearly indicate that linear modifiers such as traditional ethylene-propylene copolymers are ineffective in impact toughening, while long chain branched polymers provide enhanced impact resistance with a ductile failure mode in high flow polypropylenes.