The Effect of H-Bonding on Radical Copolymerization of Maleic Anhydride with N-tert-Butylacrylamide and Its Characterization

Table 1

¹H NMR, FTIR, and elemental analysis of NTBA/MA copolymers synthesized from various monomers feed ratio.

Feed mol ratio NTBA/MA	Am 1 (NTBA)^a	Am 2 (MA)^a	Δ𝐴1^b; 1658 cm^−1; integral area	Δ𝐴2^b; 1775 cm^−1; integral area	Copolymer composition (mol%)				FTIR analysis
					^1H NMR analysis		Nitrogen analysis
			𝐴𝑚1(NTBA)	𝐴𝑚2(MA)	𝑚1	𝑚2	𝑚1	𝑚2	𝑚1	𝑚2
70/30	0.065	0.054	0.510	0.280	66.5	33.5	65.8	34.2	66.1	33.9
60/40	0.048	0.042	0.468	0.312	58.4	41.6	60.8	39.2	59.2	40.8
50/50	0.056	0.047	0.487	0.455	55.1	44.9	54.5	45.5	54.1	45.9
40/60	0.034	0.030	0.405	0.587	50.2	49.8	48.8	51.2	48.7	51.3
30/70	0.023	0.024	0.355	0.865	47.6	52.4	46.6	53.4	46.8	53.2

aIntegral area for CH chemical shift of NTBA (terbutyl group) and MA anhydride (methyne group) units.
^bThe values of Δ𝐴₁=0.178 and Δ𝐴₂=0.275 for poly (NTBA) and poly (MA), respectively; 1365 cm⁻¹ is used as a less changed standard band.