RSC Advances
Paper
ꢁ
1
29.42, 123.19, 94.24, 42.75, 41.83, 37.62, 28.31, 26.20, 24.39. solution for 30 min. The polymerization was carried out at 60 C
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1
FTIR (cm ): 2943, 2883, 1771, 1698, 1630, 1425, 1394, 1328, during 40 h to attain total conversion. The homopolymer and
266, 1051, 982, 851, 718. MS (ESI): calculated m/z 299.139 copolymers were isolated and puried by several cycles of
1
+
(
M + 1) , found m/z 299.139.
-(3-Aminopropyl)-1-vinyl-2-pyrrolidone (VPNH
8.63 mmol) and hydrazine monohydrate (NH NH
precipitation–solution–precipitation in diethylether–chloro-
). VPPhta form–diethylether.
$H O) (6.40 Poly-VPNH homopolymer and poly-(VP-co-VPNH
3
2
(
2
2
2
2
2
) copoly-
mL, 130 mmol) were dissolved in EtOH (270 mL), and le to stir mers. Homo and copolymers with amino groups were obtained
at room temperature. The formation of a white solid in the by reduction of the corresponding phthalimide containing
reaction solution indicates that the reaction is proceeding. Aer polymers using hydrazine monohydrate (same amounts as
4
0 hours, the white solid (leaving group) was removed by simple indicated in the monomers synthesis protocol). Products were
ltration, and the solvent was evaporated at low pressure. 250 mL isolated and puried by dialysis using membranes of cut-off
of diethylether was added to the remainder, upon which more 1000 Da, followed by freeze drying.
leaving group solid appeared. Aer ltration, anhydrous MgSO Poly-(VP-co-VP-2PE) copolymer. Monomers and initiator
was added and ltered. Solvent was removed at low pressure (AIBN) were dissolved in 1,4-dioxane at a concentration of 1.0
4
ꢀ
1
ꢀ2
ꢀ1
yielding a pallid yellow semicrystalline liquid. Yield: 95%.
mol L and 1.5 ꢂ 10 mol L , respectively. Gaseous N
2
was
1
H NMR (DMSO-d
6
, 500 MHz): d ¼ 6.88 (dd, 1H, C–H, 15.0 ushed through the polymerizing solution for 30 min. The
ꢁ
and 9.0 Hz), 4.45 (d, 1H, trans N–CH]CHH, J ¼ 15.0 Hz), 4.42 (d, polymerization was carried out at 60 C for 40 h to attain total
1
H, cis N–CH]CHH, J ¼ 9.0 Hz), 3.43 (dt, 1H, N–CHH, J ¼ 12.0 conversion. The copolymer was isolated and puried by
and 3.0 Hz), 3.30 (td, 1H, N–CHH, J ¼ 12.0 and 6.0 Hz), 2.54–2.44 precipitation–solution–precipitation cycles using diethylether–
(m, 3H, CH –NH and CH–CO), 2.26–2.19 (m, 1H, CO–CH–CHH), chloroform–diethylether.
2 2
1
.71–1.62 (m, 2H, CO–CH–CHH and CHH–CH
2
–CH
2
), 1.42–1.24
1
3
(m, 3H, CH
2 2 2 2 2
–CH –CH , CHH–CH –CH ). C NMR (DMSO-d
6
,
Methods
1
2
1
25 MHz): d ¼ 175.74, 129.52, 95.55, 43.22, 42.12, 41.72, 30.50,
1
13
H and C NMR spectra were recorded using a VARIAN NMR
system (500 and 125 MHz, respectively) in CDCl using tetra-
ꢀ1
8.47, 24.30. FTIR (cm ): 3341, 2932, 2857, 1684, 1630, 1563,
3
470, 1427, 1388, 1326, 1265, 981, 844, 821, 723, 691. MS (ESI):
methylsilane (TMS) as the internal standard. Gel permeation
chromatography (GPC) analyses were carried out with Resipore
+
calculated m/z 169.133 (M + 1) , found m/z 169.134.
3-(3-((3-Oxo-3-(2-phenoxyethoxy)propyl)amino)propyl)-1-vinyl-
(
250 ꢂ 4.6 mm, 3 mm nominal particle size) Polymer Labora-
2
-pyrrolidone (VP-2PE). A solution of VPNH2 (200.0 mg, 1.19
tories columns. DMF with 1% LiBr was used as the solvent.
mmol), 2-phenoxyethyl acrylate (207.0 mg, 1.19 mmol) and AcOH
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Measurements were performed at 70 C at a ow rate of 0.7 mL
min using a RI detector. The molecular weights of the poly-
mers were referenced against polystyrene standards.
Thermal stability of poly-(VP-co-VP-2PE) and PVP were esti-
mated by thermogravimetry analysis registered in a TGA
equipment model Q500, using sample weight of 6 mg,
temperature range 25 to 500 C, at 10 C min , under nitrogen
atmosphere. Differential scanning calorimetry was carried out
in a Perkin-Elmer DSC7 equipment under nitrogen atmosphere,
using 12 mg of sample weight with a temperature range of 30–
ꢁ
(25 mL) in CHCl
3
(2.5 mL) was stirred at 40 C for 4 h. The reaction
ꢀ1
was monitored by TLC. The solvent was evaporated under low
pressure and the crude mixture was puried by column chro-
matography in silica gel, using AcOEt/Hexane/Et N (30 : 10 : 2) as
3
the eluent, resulting a white solid. Yield: 90%.
1
H NMR (CDCl , 500 MHz): d ¼ 7.28 (t, 2H, C–H, J ¼ 7.5), 7.08
ꢁ
ꢁ
ꢀ1
3
(
7
dd, 1H, N–CH]CH , J ¼ 16.0 and 9.0 Hz), 6.96 (t, 1H, C–H, J ¼
2
2
.5), 6.92–89 (m, 2H, C–H) 4.45–4.36 (m, 4H, N–CH]CH and
COO–CH
CHH, J ¼ 10.0 and 3.5 Hz), 3.36 (dt, 1H, N–CHH, J ¼ 10.0 and 8.0
Hz), 2.89 (t, 2H, NH–CH –CH
–COO, J ¼ 6.5 Hz), 2.65–2.60 (m,
H, CH CH CH –NH), 2.58 (t, 2H, CH
–COO, J ¼ 6.5 Hz), 2.49
2 2 2
), 4.18–4.16 (m, 2H, COO–CH CH –O), 3.48 (td, 1H, N–
ꢁ
ꢁ
ꢀ1
2
00 C and a heating rate of 20 C min . Glass transition
temperature, T , was measured in the second scan and taken as
the inexion point of the transition region of the T
2
2
g
2
2
2
2
2
g
.
(
qd, 1H, CH–CO, J ¼ 9.0 and 4.5 Hz), 2.29–2.23 (m, 1H, N–CH –
2
Determination of reactivity ratios. Assuming that the copo-
CHH), 1.91–1.67 (m, 3H, N–CH –CHH, –NH– and CO–CH–
27
2
lymerization is governed by the terminal model, the reactivity
ratios of the copolymerization of VPPhta and VP in 1,4-dioxane
were determined using Copol soware. The terminal model
copolymerization can be used for descriptive purposes although
CHH), 1.54 (quint, 2H, J ¼ 7.5 Hz), 1.44–1.36 (m, 1H, CO–CH–
1
3
CHH). C NMR (CDCl
3
, 125 MHz): d ¼ 174.90, 172.65, 158.39,
28
1
4
1
1
3
29.48, 121.15, 114.56, 94.14, 65.75, 62.79, 42.45, 44.92, 42.80,
ꢀ
1
2.20, 34.57, 28.79, 27.56, 24.32. FTIR (cm ): 2929, 2881, 2825,
733, 1697, 1630, 1599, 1589, 1494, 1426, 1387, 1327, 1245,
168, 1120, 1060, 982, 849, 754, 692. MS (ESI): calculated m/z
29,30
it is well documented that it is only an approximate model.
The terminal model considers the reactivity of the growing
chain to depend on the nature of the terminal unit, and in the
case of binary copolymerizations needs two parameters –
namely, the reactivity ratios – to describe the reaction. These
+
61.212 (M + 1) , found m/z 361.212.
reactivity ratios are given by eqn (1) and (2).
Synthesis of polymers
.
Poly-VPPhta homopolymer and poly-(VP-co-VPPhta) copoly-
mers. Monomers and initiator (AIBN) were dissolved in 1,4-
r
1
2
¼ k11
¼ k22
k
12
21
(1)
(2)
ꢀ
1
ꢀ2
ꢀ1
.
dioxane at concentrations of 0.6 mol L and 1.5 ꢂ 10 mol L
,
r
k
respectively. Gaseous N was ushed through the polymerizing
2
35952 | RSC Adv., 2014, 4, 35950–35958
This journal is © The Royal Society of Chemistry 2014