Polyamides of 1,4‐cyclohexanebis(methylamine)

Polyamides of both cis ‐ and trans ‐1,4‐cyclohexanebis(methylamine) with aliphatic dicarboxylic acids and copolyamides of trans ‐1,4‐cyclohexanebis(methylamine) with p ‐xylene‐α,α′‐diamine were prepared in order to discover the effect of cycloalkane rings on melting point. Analogous polyamides of p ‐xylene‐α,α′‐diamine were prepared for comparison. The polyamides of trans ‐1,4‐cyclohexanebis(methylamine) had higher melting points than the analogous polyamides of p ‐xylene‐α,α′‐diamine. This result is believed to be due to the slightly contracted conformation which trans ‐1,4‐cyclohexanebis(methylamine) can adopt in the polymer chain. The polyamides of cis ‐1,4‐cyclohexanebis(methylamine) melted lower than those of the trans isomer. The lower symmetry of the cis ‐diamine accounts for this result. The melting points of the copolyamides of trans ‐1,4‐cyclohexanebis(methylamine) and p ‐xylene‐α,α′‐diamine were higher than expected. It is suggested that these compositions are examples of partially isomorphous copolyamides.