STUDYING VULCANIZATION OF FLUOROCOPOLYMERS WITH POLYAMINES BY INFRARED SPECTROSCOPY METHOD,
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
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It was found that the vulcanization of a hexafluoropropylene-vinylidene fluoride with hexamethylenediamine HMDA results in the formation of a HMDAhydrofluoride salt as a result of dehydrofluorination of the copolymer and the formation of double bonds in the polymer chain which, in turn, join with a portion of the HMDA to form C-N and CN bonds. In the presence of MgO the same bonds are formed, but without the formation of the HMDA-hydrofluoride. Heating the mixture of the copolymer and HMDA-HF results in the dehydrofluorination of the latter compound, making additional HMDA available for bond formation. The separated HF, however, tends to disrupt the CN bonds. The susceptibility of these bonds may be the primary cause of the relatively low heat and acid resistance of fluoro-copolymers vulcanized with polyamines.
- Elastomers and Rubber