Accession Number : ADA265799


Title :   13C and 15N Solid-State NMR of Copolymers of Nylon 6 and 7: Observation of a Stable Pseudohexagonal Phase


Descriptive Note : Technical rept. 1 Jun 92-31 May 93,


Corporate Author : UNIVERSITY OF SOUTHERN MISSISSIPPI HATTIESBURG DEPT OF POLYMER SCIENCE


Personal Author(s) : Johnson, C G ; Mathias, L J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a265799.pdf


Report Date : 07 Jun 1993


Pagination or Media Count : 20


Abstract : We have synthesized and characterized a series of nylon copolymers based on the even-odd A-B monomer combination, caprolactam and enantholactam. The nylon 6-co-7 samples obtained were found to possess physical properties which directly correlate with copolymer composition. We have determined degrees and types of crystallinity for these materials using a combination of thermal, NMR and X-ray measurements. The homopolymers each display highly ordered alpha- crystallites while the copolymers possess less-ordered domains that decrease in alpha-like characteristics down to the 1:1 copolymer which possesses a thermodynamically stable pseudohexagonal ordered phase. The 13C T1 values determined for the annealed 1:1 copolymer were shorter than those of crystalline regions of homopolymers, comparable to those observed for amorphous domains in melt quenched nylon 6 and nylon 7 homopolymers, and significantly longer than the values for precipitated and annealed 1:1 nylon 11-co-12 sample.


Descriptors :   *PHYSICAL PROPERTIES , *NYLON , *COPOLYMERS , NUCLEAR MAGNETIC RESONANCE , QUENCHING , THERMAL ANALYSIS , THERMODYNAMIC PROPERTIES , MONOMERS , CHEMICAL COMPOSITION , AMORPHOUS MATERIALS , SYNTHESIS(CHEMISTRY) , X RAY DIFFRACTION


Subject Categories : Polymer Chemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE