COPOLYMERIZATION OF ACRYLIC ACID
1573
b' was monitored by TLC on plates Silufol UV-254, reaction products were carried out analogously to the
eluent: DMF–alcohol at a volume ratio of 2 : 1, with previous method, but 10.3 g (0.1 moles) of biuret reacted
the manifestation of iodine vapor. After distilling off with 14.2 g (0.2 moles) ofAAand 16 mLof 38% aqueous
the AA a fraction of bp 140.9°C was used. Acrylamide formaldehyde solution (0.2 moles). Matte product
was used after crystallization from benzene, mp 84.5°C. (mp 98 ± 2°C) was produced. Yield 16.47 g, 54.0%.
Copolymerization of AA with a' and b' was performed
according to the procedure described in [1] using reduced
molar ratios of [AA]/[ABD]. For the copolymerization
(NH4)2S2O8 (analytically pure) was used as the initiator.
All the copolymers were washed repeatedly with an aque-
ous ethanolic solution at a volume ratio of 1 : 2, ethanol,
and acetone. The composition of the copolymers obtained
was determined by elemental analysis for N, C, and H.
For obtaining –COONa functional groups in the copoly-
mers a required amount of an aqueous alkali solution was
introduced in their crosslinked swellable gels. Then water
was completely removed under a vacuum (10–15 mmHg)
at 50–55°C, and afterwards repeated washing with warm
ethanol and drying under vacuum (1.5–2 mmHg) to con-
stant weight were carried out.
IR spectrum, ν, cm–1: 1415–1430 [=N–(C=O)–N=];
1520–1540, 3215, 3360 (N–H); 1645–1650 (CH2=CH–);
1670–1685 [–(C=O)–NH–CH2–]; 1695–1709 [–(C=O)–
NH–(C=O)–].
1H NMR spectrum, δ, ppm: 4.20–4.31 d (4H, NCH2),
4.45–4.50 d (4H, CH2), 5.74–5.83 s (2H, CH), 6.40–6.48
and 6.61–6.75 s (5H, NH). Found, %: C 44.70, H 5.50,
N 25.90. C10H15N5O4. Calculated, %: C 44.61, H 5.58,
N 26.02.
N-methylolacrylamide. Acrylamide [7.1 g
(0.1 moles)] , 7.9 mL of 38% aqueous formaldehyde
solution in 17.1 mL of distilled water at pH 7–9
and a temperature of 35–40°C were stirred until the
disappearance of formaldehyde odor (1–1.5 h). Then
under vacuum (10–15 mmHg) at 20–25°C water was
distilled off. The resulting clear viscous blend was
repeatedly washed with chloroform and chloroform–ethyl
acetate mixture in a volume ratio of 2 : 1. The blend was
dried under vacuum (1.5–2 mmHg) at 30–35°C to constant
weight. Yield 7.27 g, 72%. N-methylolacrylamide is
amorphous, transparent product of matte shade, which
is soluble in water, alcohols, esters.
IR spectrum, ν, cm–1: 1640–1650 (CH2=CH–); 1680–
1690 [–(C=O)–NH–CH2–]; 1050–1080, 3400–3550
(–OH).
1H NMR spectrum, δ, ppm: 3.58–3.6 s (N–CH2),
4.44–4.53 d (2H, CH2), 5.0–5.1 s (1H, OH), 5.7–5.78
(1H, CH). Found, %: C 47.60, H 6.85, N 13.90. C4H7NO2.
Calculated: C 47.52, H 6.93, N 13.86.
Acrylamidyl methyl biuret a or a'. In steel reac-
tor under a pressure of 0.1–0.2 kPa at 20–25°C 10.3 g
(0.1 moles) of biuret with 7.1 g (0.1 moles) of AA and
8 mL of 38% aqueous formaldehyde (a content of CH2O
was 3.04 g or 0.1 moles) were mixed. Stirring was carried
out until the disappearance of the odor of formalin. The
resulting blend was repeatedly washed with ethanol–wa-
ter mixture in a volume ratio of 1 : 3 and then with ac-
etone. Then it was dried under vacuum (1.5–2 mmHg) at
50–55°C to constant weight.Amatte crystalline substance
(mp 170 ± 2°C) was obtained. Yield 11.04 g, 63.5%.
IR spectrum, ν, cm–1: 1420 [=N–(C=O)–N=]; 1520,
3210, 3360 (N–H); 1648–1655 (CH2=CH–); 1665–1680
[–(C=O)–NHCH2–]; 1695–1705 [–(C=O)–NH–(C=O)–].
1H NMR spectrum, δ, ppm: 4.25–4.33 d (2H, NCH2),
4.43–4.51 d (2H, NH2), 4.43–4.51 d (2H, CH2), 5.01 s
(2H, NH3), 5.74–5.85 s (1H, CH), 6.42–6.49 and 6.62–
6.73 s (3H, NH). Found, %: C 38.60, H 5.40, N 30.0.
C6H10N4O3. Calculated, %: C 38.71, H 5.38, N 30.1.
AA copolymers with acrylamide derivatives. The
copolymerization of AA and acrylamide derivatives a',
b' was carried out in an aqueous medium in the molar
ratios indicated in Table 1 at a temperature of 70 ± 0.5°C
in the presence of (NH4)2S2O8 as an initiator, the content
of which was 0.1% of the AA. The copolymerization of
these monomers was carried out to a 10% conversion of
their total concentration.
Biuret reaction between formaldehyde,AAand isola-
tion of the reaction products were carried out analogously
to the previous method, but with the difference that 10.3 g
(0.1 moles) of biuret interacts with 14.2 g (0.2 moles) of
AA and 16 mL of 38% aqueous formaldehyde solution
(0.2 moles). Got matte product was of mp 98 ± 2°C. Yield
16.47 g, 54.0%.
CONCLUSIONS
(1) It was shown that the acrylamide biuret derivatives
are of cyclic structure and easily copolymerized with
acrylic acid.
Bis(acrylamidyl methyl) biuret b or b'. The reaction
of biuret with formaldehyde, AA, and isolation of the
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 87 No. 10 2014