1. University of Basra, Basra-Iraq
Synthesis and thermal study of multi arms nano block copolymers via combination of ROP and thio-click chemistry
Hadi Al-Lami
University of Basra, Basra-Iraq

2. Presentation Outline
Applications scope of smart polymers.
Definition of CRP, ROP, and Thio-Click Chemistry.
Synthesis of nano multi arms block copolymers.
Characterization by: FTIR, NMR (1H &13C), and GPC.
Microstructure Studies.
Swelling, biodegradability and drug release study.
Thermal studies.
Conclusions.

5. Methods used to prepare multi arms nano block copolymers
CRP may defined as a polymerization reaction, where no unwanted side reactions such as transfer or termination take place, and where all polymer chains are initiated at the same time.
ROP is a form of polymerization, in which the active terminal end can react by opening its ring and form a longer polymer chain.
"Click Chemistry" is a term that was introduced by Sharpless in 2001 to describe reactions that are highly selective, yielding and wide in scope.

6. Preparation of (Pentaerythritol-lactide) polymer (PL10, PL25, PL50, and PL100)

7. (Pentaerythritol-Lactide Bromide)-(hydroxy ethyl acrylamide) copolymer

8. Preparation of Thiolate POSS by Thio-Click reaction of Octavinyl POSS with 2-Mercapto ethanol

9. (Thiolate POSS -Lactide Bromide)-(N-hydroxy ethyl acrylamide) copolymer

10. Characterization
Characterization of (Pentaerythritol- lactide) polymers (PL10, PL25, PL50 and PL100) by FT-IR

11. Characterization of (Pentaerythritol-lactide) polymers (PL10, PL25, PL50 and PL100) by 1H NMR

12. Characterization of (Pentaerythritol-lactide) polymers (PL10, PL25, PL50 and PL100) by 13C NMR

13. Characterization of Thiolate POSS by FT-IR

14. Characterization of Thiolate POSS by 13C NMR

15. Characterization of (Thiolate POSS-lactide) polymers: (TL10, TL25, TL50, and TL100) by FT-IR

16. Characterization of (Thiolate POSS- lactide) polymers: (TL10, TL25, TL50, and TL100) by 1H NMR

17. Characterization of (Thiolate POSS- lactide) polymers: (TL10, TL25, TL50, and (TL100) 13C NMR

18. Gel Permeation Chromatography (GPC)
No.
Polymer Name
Calculated Mn
(Daltons)
Found Mw
Polydispersity Index
(PDI) 1
PL10
3018
3063
3317
1.08 2
PL25
7342
7319
8351
1.14 3
PL50
14549
14563
15805 4
PL100
28962
28903
31102
1.07 5
TL10
7023
7094
8164
1.15 6
TL25
15671
15653
17364
1.10 7
TL50
30084
29995
32998 8
TL100
58911
58951
61130
1.03

19. No.
Copolymer Name
Value of
(m) Mn
(Daltons) Mw
Polydispersity Index
(PDI) 1
PL10BrNm 12
9126
10347
1.13 2
PL25BrNm 29
21264
23815
1.11 3
PL50BrNm 59
42266
43383
1.02 4
PL100BrNm
113
81502
87810
1.07 5
PL10BrDm 13
11725
12651 6
PL25BrDm 28
25475
27339 7
PL50BrDm 57
50947
58105
1.14 8
PL100BrDm
115
101795
110018
1.08 9
TL10BrNm
20138
21673 10
TL25BrNm 30
44496
50770 11
TL50BrNm 60
86484
93180
TL100BrNm
165933
176655
1.06
TL10BrDm
23257
25066 14
TL25BrDm 31
55860
59243 15
TL50BrDm 58
104177
121661
1.16 16
TL100BrDm
116
205861
284755
1.38

20. Scanning Electron Microscopy (SEM)

22. Biodegradability Studies
Swelling Studies
The swelling ratio for all prepared were studied as a function of time at three different pH, 1.2, 7 and 8.4. The obtained data showed that the swelling ratio decreasing as PLA chain length increases.
Biodegradability Studies
Hydrolytic degradation studies were followed as well at same pH (1.2, 7 and 8.4) for 7 weeks with 40% as maximum degradation. Hydrolytic degradation percent was decreased with increasing of PLA chain length.

23. Thermogravimetric Analysis
TGA thermogram of of PL10

24. Polymer Ti
(oC) Tf
Rate of Decomposition
% wt / min
Activation Energy
KJ.mol-1
Weight Loss
(%)
T50
PL10
176.56
201.47
6.33
0.011
94.33
186.03
PL25
181.93
213.09
3.96
0.013
97.09
190.60
PL50
211.49
231.62
3.21
94.09
215.94
PL100
233.26
291.67
1.95
0.026
98.78
253.57

25. Polymer Ti
(oC) Tf
Rate of Decomposition
% wt / min
Activation Energy
KJ.mol-1
Weight Loss (%)
T50
TL10
189.31
219.05
3.92
0.075
98.09
198
TL25
191.55
246.43
2.32
0.079
92.09
201
TL50
229.94
260.29
2.29
0.086
99.09
235
TL100
252.22
304.76
1.88
0.092
98.58
265

27. Copolymer Ti (oC) Tf Rate of Decomposition % wt/min Activation Energy
Activation Energy
kJ.mol-1
Weight Loss (%)
T50%
PL10BrDm
1st. decomp.
145.82
216.80
0.38
0.015
27.77
294.05
2nd. decomp.
289.74
332.14
0.67
0.016
53.84
PL25BrDm
158.33
241.70
0.37
0.020
24.95
296.43
295.37
330.76
0.65
0.018
57.84
PL50BrDm
173.92
246.26
0.32
0.023
32.71
292.32
291.71
345.24
0.42
0.021
48.2
PL100BrDm
190.03
253.74
0.31
0.044
20.97
315.48
306.03
346.43
0.51
0.033
64.17

28. Conclusions
The following conclusions can be withdrawn from the current work: 1. Combination of ROP with the Thio-click chemistry has been reached with successes using ATRP macroinitiator. 2. A series of block copolymers pentaerythritol-Lactide and thiolate POSS-Lactide multi arms nano block copolymers were obtained. 3. FT-IR, 1HNMR and 13CNMR were proved the structures for the prepared copolymers. 4. GPC results revealed that all the tested copolymers are of nearly monodisperse polymer.

29. 5. Lactide polymer chains exhibited a nano structure as
they examined by SEM.
6. The ability of the prepared polymer to degraded in vitro and in
vivo, and they exhibited excellent biocompatibility with human
plasma with no toxicity.
7. The release rate of insulin can be designed by choosing the suitable
conditions and can be given orally.
8. Thermal studies showed better stability of the multi arms
copolymers as lactide units increased and POSS is present.