Table 1. ¹H- and ¹³C-NMR data of PA cyclic monomers and oligomers.

Monomers and oligomers	Nucleus	Chemical shift data (ppm)
		1	2	3	4	5	6	7
PA6 monomer(CPL)	1H	7.60 (s)	3.23 (2H, m)	1.64–1.70a (m)	1.80 (2H, m)	1.64–1.70a	2.47	-
						(m)	(2H, t)
	13C	-	44	30.8	31.8	24.5	37.6	182
PA6 dimer	1H	7.59 (s)	3.27 (4H, t)	1.28 (4H, m)	1.63 (4H, m)	1.48	2.2	-
						(4H, m)	(4H, t)
	13C	-	40	30.1	26.7	26.4	37.1	176.5
PA6 trimer	1H	7.60 (s)	3.21 (6H, t)	1.34 (6H, m)	1.64 (6H, m)	1.53	2.22	-
						(6H, m)	(6H, t)
	13C	-	40.3	29.6	27	26.3	37	176.4
PA6 tetramer	1H	7.59 (s)	3.20 (8H, t)	1.33 (8H, m)	1.64	1.52	2.21	-
					(8H, m)	(8H, m)	(8H, t)
	13C	-	40.4	30.1	27.4	26.7	37.2	176.3
PA6 pentamer	1H	7.60 (s)	3.18 (10H, t)	1.33 (10H, m)	1.63	1.52	2.19	-
					(10H, m)	(10H, m)	(10H, t)
	13C	-	40.5	30.3	27.6	26.8	37.4	176.1
PA6 hexamer	1H	7.60 (s)	3.20 (12H, t)	1.34 (12H, m)	1.64	1.53	2.21	-
					(12H, m)	(12H, m)	(12H, t)
	13C	-	40.4	30.1	27.4	26.7	37.2	176.3
PA66 monomer	1H	7.58a	3.22 (4H, t)	1.53 (4H, s)	1.32	1.63	2.19	-
					(4H, s)	(4H, s)	(4H, s)
	13C	-	39.9	29.1	27.4	27.3	37.5	176.5
PA66 dimer	1H	7.59 (s)	3.15 (8H, t)	1.47 (8H, t)	1.31	1.6	2.18	-
					(8H, s)	(8H, s)	(8H, t)
	13C	-	40.4	30.4	27.5	26.7	37.2	176
PA66 trimer	1H	7.58a	3.17 (12H, t)	1.50 (12H, s)	1.34	1.62	2.21	-
					(12H, s)	(12H, s)	(12H, t)
	13C	-	40.5	30.4	27.6	26.7	37.1	175.9

^aOverlapped with each other.

The data were obtained in CD₃OD:CDCl₃ (1:1) solution.