Synthesis and Characterization of Linear Dendritic
Polymers
Hüseyin ESEN
huseyin.esen@yalova.edu.tr
Department of Polymer Engineering, Faculty of Engineering, Yalova University,
77100 Yalova, Turkey
Contents
Homopolymer of ACTES .......................................................................................................................... 2
ACTES copolymers: .................................................................................................................................. 3
ACTES-MMA copolymer: ..................................................................................................................... 4
ACTES-ST copolymer: .......................................................................................................................... 6
ACTES-NVP copolymer: ....................................................................................................................... 8
Determination of molar ratios .............................................................................................................. 10
Reactivitiy ratios .................................................................................................................................... 12
Finemann-Ross .................................................................................................................................. 13
Inverted Finemann-Ross ................................................................................................................... 13
Kelen-Tudos: ...................................................................................................................................... 13
Transition probabilities: ........................................................................................................................ 14
“Q” and “e” values: ............................................................................................................................... 15
ACTES and Styrene copolymer .............................................................................................................. 15
Finemann-Ross: ................................................................................................................................. 16
Inverted Finemann-Ross.................................................................................................................... 16
Kelen -Tudos ...................................................................................................................................... 17
ACTES and N-Vinyl Pyrrolidone (NVP) copolymer ................................................................................. 17
Finemann- Ross ................................................................................................................................. 18
Inverted Finemann- Ross ................................................................................................................... 18
Kelen-tudos ....................................................................................................................................... 19
1
Homopolymer of ACTES
ACTES (1.67 g, 4.77 mmol) was replaced in a schlenk tube and dioxane (4.77 ml)
was added as polymerization solvent just enough to obtain the concentration as 1M.
Benzoyl peroxide (11.5 mg) was added as 1 mol % of the ACTES. The solution was
purged with nitrogen for 30 minutes. Tube was sealed, heated to 80 C and mixed for
24 hours. Polymerization mixture was then precipitated into methanol after 24 hours,
filtered and dried (yield 73 %). Proton, carbon NMR and GPC graph are shown in
Figure1, Figure 2 and Figure 3.
p-aktes-aseton.010.esp
0.45
0.40
Normalized Intensity
0.35
0.30
0.25
0.20
0.15
0.10
0.05
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
Chemical Shift (ppm)
3.0
2.5
2.0
1.5
1.0
0.5
0
Figure 1: Proton NMR spectrum of homopolymer of ACTES
2
0.11
p-aktes-aseton.011.esp
0.10
0.09
0.08
Normalized Intensity
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
-0.01
180
160
140
120
100
80
Chemical Shift (ppm)
60
40
20
0
Figure 2: Carbon NMR spectrum of homopolymer of ACTES
Figure 3: GPC of ACTES homopolymer
ACTES copolymers:
General procedure for the synthesis of copolymers was as follows 0,6012 g (1,28
mmol) ACTES, selected amount of comonomer (after removal of inhibitor) and
benzoyl peroxide (1 mol % of total polymerizable monomers) were placed into
schlenk tube and dissolved in 8 ml dioxane. Solution was purged with nitrogen for 30
3
minutes and sealed. Mixture was heated up to 90 C in glycerol bath and mixed for
overnight. Mixture was precipitated into methanol upon cooling, then filtered and
dried.
ACTES-MMA copolymer:
Synthesis of copolymer was as follows 0,6012 g (1,28 mmol) ACTES and 0,0602 g
(0,2528 mmol) benzoyl peroxide (1 mol % of total polymerizable monomers) were
placed into schlenk tube and dissolved in 8 ml dioxane. 2.4 g (24 mmol) MMA
(removed from inhibitor) was added and purged with nitrogen for 30 minutes and
sealed. Mixture was heated up to 90 C in glycerol bath and mixed for overnight.
Mixture was precipitated into methanol upon cooling, then filtered and dried (yield 84
%). FT_IR, Proton NMR spetra, GPC and DSC graphs were shown in Figure 4,
Figure 5, Figure 6 and Figure 7, respectively.
100.6
95
90
2992.06
2950.43
1388.32
842.66
85
1480.61
1367.91
1066.29
986.72
964.85
750.11
80
1435.08
75
1239.48
%T 70
65
1190.01
60
55
1723.52
50
1143.55
45
42.5
4000.0
3600
3200
2800
2400
2000
1800
cm-1
1600
1400
1200
1000
800
650.0
Figure 4: FT-IR spectrum of ACTES-MMA copolymer
4
Figure 5: Proton NMR spectrum of ACTES-MMA copolymer
Figure 6: GPC result of ACTES-MMA copolymer
5
Figure 7: DSC curve of ACTES-MMA copolymer
ACTES-ST copolymer:
Synthesis of copolymer was as follows 0,6012 g (1,28 mmol) ACTES and 0,0602 g
(0,2528 mmol) benzoyl peroxide (1 mol % of total polymerizable monomers) were
placed into schlenk tube and dissolved in 8 ml dioxane. 2.4 g (23.01 mmol) styrene
(removed from inhibitor) was added and purged with nitrogen for 30 minutes and
sealed. Mixture was heated up to 90 C in glycerol bath and mixed for overnight.
Mixture was precipitated into methanol upon cooling, then filtered and dried (yield 73
%). FT_IR, Proton NMR spetra, DSC and TGA graphs were shown in Figure 8,
Figure 9, Figure 10 and Figure 11, respectively.
Figure 8: FT-IR spectrum of ACTES-ST copolymer
6
Figure 9: Proton NMR spectrum of ACTES-ST copolymer
Figure 10: DSC graph of ACTES-ST copolymer
7
Figure 11: TGA graph of ACTES-ST copolymer
ACTES-NVP copolymer:
Synthesis of copolymer was as follows 0,6012 g (1,28 mmol) ACTES and 0,0602 g
(0,2528 mmol) benzoyl peroxide (1 mol % of total polymerizable monomers) were
placed into schlenk tube and dissolved in 8 ml dioxane. 2.4 g (21.6 mmol) NVP
(removed from inhibitor) was added and purged with nitrogen for 30 minutes and
sealed. Mixture was heated up to 90 C in glycerol bath and mixed for overnight.
Mixture was precipitated into methanol upon cooling, then filtered and dried (yield 77
%). FT_IR, DSC and TGA graphs were shown in Figure 12, Figure 13 and Figure 14,
respectively.
Figure 12: FT-IR of ACTES-NVP copolymer
8
Figure 13: DSC graph of ACTES-NVP copolymer
Figure :14 TGA graph of ACTES-NVP copolymer
9
Determination of molar ratios
In situ NMR technique was applied to determine conversions of monomers.
Polymerization mixture was prepared in NMR tube with deutero DMSO and initial
spectrum was acquired at room temp. And sample was ejected. Then NMR probe
was heated to 90 C and sample was inserted and NMR spectrum were collected
every 15 minutes. Conversion of monomers were followed by the decrease in
normalized intensities of signal coming from unsaturations. Reactions and
acquisitions were halted before 10 % conversions of monomers.
Conversions of styrene, N- vinyl pyrrolidone and ACTES monomers were calculated
according to the equation (1) below where A0 is the initial normalized integral of the
monomer peak and At is the normalized integral of the monomer peak at time t.
Proton NMR spectra of the initial mixtures of ACTES-styrene and ACTES-NVP were
given below in Figure 15 and Figure 16, respectively. In both spectra signal coming
from unsaturations of all monomers donot coincide with each other and are suitable
to follow conversions.
Figure 15: Proton NMR spectra of the initial mixture of ACTES-ST
10
Figure 16: Proton NMR spectra of the initial mixture of ACTES-NVP
Mole fractions of styrene and ACTES in the copolymer compositions can be
determined from following equations:
Mole fractions of NVP and ACTES in the copolymer compositions can be determined
from following equations:
11
For the copolymerization reaction of styrene and ACTES, “f” and “F” were obtained
by simplification of above equations as:
For the copolymerization reaction of NVP and ACTES, “f” and “F” were obtained by
simplification of above equations as:
Reactivitiy ratios
Reactivity ratios were determined according to the Finemann-Ross, Inverted
Finemann-Ross and Kelen-Tudos methods. In all methods parameters to determine
the reactivity ratios were calculated from “f”, the feed ratio and “F”, composition in the
copolymer.
12
Finemann-Ross
Parameters used in Finemann-Ross method to obtain reactivity ratios, “G” and “H”
were obtained with following equations.
Reactivity ratios of the monomers were obtained from the linear relationship below:
Inverted Finemann-Ross
Reactivity ratios are also obtained from inverted Finemann-Ross method with the
following equation:
Kelen-Tudos:
The parameters for the Kelen-Tudos method were also given as:
Ƞ = G / (α + H)
13
Transition probabilities:
By using the reactivity ratios of styrene and ACTES it is possible to find probability
p11 of forming M1M1 dyads in the copolymer at a given monomer feed
Similarly, the probabilities p12, p21 and p22 for forming pairs of M1M2, M2M1 and M2M2,
respectively, are given by
Also number average monomer sequence lengths can be obtained by following
formulas:
14
“Q” and “e” values:
ACTES and Styrene copolymer
Copolymer M1 M2
α = 1,327
ACT-ST1
8
2
ACT-ST2
6
4
ACT-ST3
4
6
ACT-ST4
2
8
F
4
1,5
0,67
0,25
f
G
H
Ƞ
ξ
1,644 1,568 9,732 0,142 0,880
1,096 0,131 2,053 0,039 0,607
0,809 -0,158 0,555 -0,084 0,295
0,344 -0,476 0,181 -0,316 0,120
Conversiona (%)
8,5
12
7,4
7,03
Table 1. Finemann-Ross, Inverted Finemann-Ross ve Kelen-Tudos parameters for
ACTES-Stiren monomer pair. a : Conversion averages of ACTES and Styrene
monomers.
15
Finemann-Ross:
Figure17. “Finemann – Ross” graph for ACTES and Styrene monomer pair.
Inverted Finemann-Ross
Figure 18. “Inverted Finemann – Ross” graph for ACTES and Styrene monomer pair.
16
Kelen -Tudos
Figure 19. “Kelen Tudos” graph for ACTES and Styrene monomer pair.
ACTES and N-Vinyl Pyrrolidone (NVP) copolymer
Copolymer M1 M2
F
f
G
H
Ƞ
α = 1,69
ACT-VP1
8
2
4
1,776 1,748 9,011 0,163
ACT-VP2
6
4
1,5 0,901 -0,165 2,497 -0,039
ACT-VP3
4
6 0,67 0,576 -0,493 0,779 -0,200
ACT-VP4
2
8 0,25 0,197 -1,019 0,317 -0,508
ξ
Conversiona (%)
0,842
0,596
0,316
0,158
9,9
7,6
5,4
3,8
Table 2. Finemann-Ross, Inverted Finemann-Ross ve Kelen-Tudos parameters for
ACTES-NVP monomer pair. a : Conversion averages of ACTES and NVP
monomers.
17
Finemann- Ross
Figure 20. “Finemann – Ross” graph for ACTES and NVP monomer pair.
Inverted Finemann- Ross
Figure 21. “Inverted Finemann – Ross” graph for ACTES and NVP monomer pair.
18
Kelen-tudos
Figure 22. “Kelen Tudos” graph for ACTES and NVP monomer pair.
19