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Inorganic coordination polymers. XVIII. Observations on brittle and flexible films of {Cr[OP(CH 3 )(C 6 H 5 )O] 2 [OP(C 8 H 17 ) 2 O]} x

1975; Wiley; Volume: 13; Issue: 12 Linguagem: Inglês

10.1002/pol.1975.170131220

1542-9369

Piero Nannelli, H. D. Gillman, B. P. Block,

Metal complexes synthesis and properties

Abstract Films of {Cr[OP(CH 3 )(CH 6 H 5 )O] 2 [OP(C 8 H 17 ) 2 O]} x , formed during the reaction of {Cr(OH)[OP(CH 3 )(C 6 H 5 )O] 2 } x with dioctylphosphinic acid, are either brittle or flexible depending on the details of the preparation of the chromium(III) bisphosphinate precursor. Both kinds of film appear to contain mainly triple‐bridged chains. Differing degrees of randomness in distribution of the two kinds of phosphinate bridges and, hence, of the internally plasticizing octyl groups along the chain account for the observed differences in flexibility, x‐ray diffraction patterns, and birefringence. The observed intrinsic viscosities of 9–18 dl/g indicate that these trisphosphinates form microgels rather than true solutions. The thermal degradation of these films proceeds by the oxidation and cleavage of the organic side groups. Addition of antioxidants to the flexible films significantly increases the longevity of their flexibility at 200°C.