1. Department of Chemistry , Faculty of Science
Preparation of Interpenetrating Network Hydrogel Film by One-pot Polymerization under Microwave Irradiation
Presented by
Miss Warunee Tanan
Department of Chemistry , Faculty of Science
Ubon Ratchathani University, Ubon Ratchathani, Thailand
Good afternoon everybody, my name is Warunee tanan. I am a master student in Ubon Ratchathani University, Thailand. Today, I would like to present about my work in the title of “PREPARATION OF INTERPENETRATING NETWORK HYDROGEL FILMS BY ONE-POT POLYMERIZATION UNDER MICROWAVE IRRADIATION”

2. Introduction 2 Hydrophilic functional group in hygrogel structure
Network
Hydrophilic functional group in hygrogel
structure
- Hydroxyl (-OH)
- Carboxyl (-COOH)
- Amide (-CONH2 or -CONH-)
Hydrogels
Crosslinking
Adsorption water
Crosslinking
Interpenetrating Polymer Network (IPN) hydrogel
Hydrogels are hydrophilic homopolymers or copolymers with three dimensional network structures Due to the hydrophilicity characteristics; they can swell quickly in water or other biological fluid without dissolving.
Formation of interpenetrating polymer networks (IPNs) could be improved mechanical property. An interpenetrating polymer networks (IPNs) is defined as a combination of two polymers in network form.
Network A
Polymer B
IPN = A + B

3. Introduction 3 Adsorption of hydrogel for water and metal ion
Hydrogen bond
Coordinate covalent bonds
This slide shows adsorption mechanisms of the hydrogels for adsorb water and heavy metal ion . In the mechanism of water adsorption, hydrogel can be adsorbed water by hydrogen bonding formation with water molecule. For the adsorption of heavy metal ions, hydrogel is formed coordinate covalent with heavy metal ions by complexation process
Cross linking
Covalent bond
O. Okay and S. B. Sariisik. Eur. Polym. J (2000 )

4. Applications Introduction 4 Pharmaceutical Industrial
Wound dressing
Pharmaceutical
Controlled drug delivery
Applications
The hydrogels have been widely used and can be applied in many applications such as wound dressing, controlled drug delivery, tissue engineering and remove heavy metal.
Due to many application of hydrogel, in this work, we was preparation of interpenetrating network (IPN) hydrogel by one-pot polymerization under microwave Irradiation and characterization of structural, surface morphology properties and adsorption efficiency of the prepared hydrogel.
Industrial
Tissue engineering
Remove heavy metal
S. Amin, S. Rajabnezhad and K. Kohli Scientific Research and Essay (2009 )

5. Initiator Crosslinker Previous our work 5
Preparation of P(AM-co-HEMA)/PVA IPN hydrogels films (conventional method)
Initiator
Monomer
Ammonium persulfate (APS)
2-Hydroxyethyl mathacrylate (HEMA)
Acrylamide (AM)
vinyl alcohol (VA)
APS
Crosslinker AM
Ethylene glycol dimethacrylate (EGDMA)
In the previous our work, we synthesized of IPN hydrogels by conventional method (detail of method was show in experimental next slide) IPN hydrogels synthsis used the material, including HEMA…AM……PVA…monomer. and APs initiator which cross linked with EGDMA
GA……………..
Glutaraldehyde (GA)
HEMA
EGDMA
Glutaraldehyde (GA)

6. Introduction 6
Preparation of P(AM-co-HEMA)/PVA IPN hydrogels films (conventional method)
Table 1 the chemical compositions of the hydrogel.
Symbol
Composition by wt%
HEMA AM
PVA
H2O
90%HEMA
2.09
0.25
2.5 95
70%HEMA
1.63
0.75
50%HEMA
1.16
1.25
30%HEMA
0.69
1.75
10%HEMA
0.23
2.25
This slide shows The chemical compositions of the synthesized IPN hydrogel by conventional method with vary amount of AM monomer. We found that, we successfully synthesized IPN hydrogel with conventional method and study the adsorption behavior of hydrogel.
We successfully synthesized IPN hydrogel with conventional method and study the adsorption behavior of hydrogel.

7. Introduction 7 Swelling behavior
Equilibrium swelling ratio
Mass swelling
(a)
(b)
The equilibrium swelling ratio and % mass swelling of the hydrogel samples were shown in Figure 3a and 3b, respectively. We found that, 10% HEMA with 2.25% of AM gave the maximum adsorption efficiency. So in this work ,10% HEMA with 2.25% of AM was selected to prepared IPN hydrogel.
Figure 1. The swelling behavior of hydrogels synthesis by conventional method (a) equilibrium swelling
ratio (b) % mass swelling of the hydrogel samples.
10% HEMA with 2.25% of AM gave the maximum adsorption efficiency

8. Introduction 8 Preparation of IPN hydrogels Conventional method
Microwave irradiation
The reaction time is long
Very slow synthesis rate
The rapid transfer of energy
in the bulk of the mixture
solution
Reduced step of preparation
Accelerated reaction rate
Improved the properties of
synthesized hydrogel
Disadvantages of the conventional method for preparation IPN hydrogl for example, the reaction time is long and very slow synthesis rate So, the microwave irradiation method was selected to prepared IPN hydrogel due to many advantages of this method for example, the rapid transfer of energy in the bulk of the mixture solution reduces step of preparation, accelerating reaction rate, improving the properties of synthesized hydrogel.

9. To study adsorption behavior of prepared IPN hydrogels
Objectives 9 1
To preparation of IPN polymer network hydrogels by monomer of 2-hydroxyethyl mathacrylate, acrylamide and vinyl alcohol 2
FT-IR
SEM 3
To study adsorption behavior of prepared IPN hydrogels
Equilibrium water
content (EWC)
% Mass swelling
To characterization of prepared IPN hydrogels
The objectives of this work are ……To preparation of IPN polymer network hydrogels by monomer of 2-hydroxyethyl mathacrylate, acrylamide and polyvinyl alcohol, …To characterization of prepared IPN hydrogels by FT-IR, SEM. And to study adsorption behavior of prepared IPN hydrogels such as Equilibrium water content (EWC) and % Mass swelling. ……………………………………………………..
One-pot solution polymerization by microwave-assisted.

10. 3. Characterization and properties of hydrogels
Experimental 10
Experimental
2. Preparation of P(AM-co-HEMA)/PVA
IPN hydrogels films
3. Characterization and properties of hydrogels
1. Preparation of mixed solution
Conventional method
Two step IPN hydrogels
synthesis
FT-IR and SEM
Adsorption behavior
%Mass swelling
Equilibrium water
content (EWC)
Microwave irradiation method
One pot IPN hydrogels
synthesis
Here is 3 part of the experimental synthesized IPN hydrogels
Part 1 shows the preparation of mixed solution, was shown in Table 1.
Part 2 shows the preparation of P(AM-co-HEMA)/PVA IPN hydrogels films, including two steps of conventional method in the synthesis IPN hydrogels and microwave irradiation method with One pot IPN hydrogels synthesis
Part 3 show the characterization of hydrogel by FT-IR, SEM and adsorption efficiency of hydrogels with %mass swelling and equilibrium water content (EWC).

11. 11 Preparation of P(AM-co-HEMA)/PVA IPN films Conventional method
Polymerization, at 50 oC ,24 h.
stirring, nitrogen atmosphere
H2O, AM , HEMA
PVA and EGDMA
Ammonium persulfate
mixed 30 min, nitrogen purging
Glutaraldehyde, HCl
Crosslink 1h and dried at
35 oC for 9h.
This slide show the preparation of P (AM-co-HEMA)/PVA IPN films by conventional method. The first, mixed solution of H2O, AM , HEMA PVA, EGDMA and TMEDA was stirred under nitrogen gas for 30 min. APS initiator was then added in the reation. After polymerization was carried out at 50 C for 24 h, glutaraldehyde and hydrochloric acid were added into the resulting solution And then crosslinking reaction for 1 h. The resulting IPN hydrogel was transferred into petri dishes and dried for 9 h at 50 C. Next, the hydrogel film was immersed in pure water for one day and dried under vacuum at 30 C for 24 h. The sample codes of hydrogel synthesized by conventional method as a 10% HEMA.
Immersed in water for 1 day, dried under vacuum at 30 oC for 24 h.
Code, 10%HEMA
Hydrogel films

12. Dried for 35 oC, 9h and immersed12
Preparation of P(AM-co-HEMA)/PVA IPN films
Microwave irradiation method
One pot solution polymerization
The reaction mixtures contained the same weight ratios as conventional method and dissolving in water.
Bubbled,
nitrogen for 1 h
The polymerization reaction was carried out microwave for 10 min.
Mixed solution
Preparation of P(AM-co-HEMA)/PVA IPN films by Microwave irradiation method with one pot solution polymerization are show in this slide. In the first step, ……The reaction mixtures contained the same weight ratios as conventional method and dissolving in water. Bubbled, nitrogen for 1 h, The polymerization reaction was carried out in ME8IY microwave for 10 min. Then dried for 35 oC, 9h and immersed in water for 1 day. Dried 30 oC, 1 day and the sample codes of hydrogel synthesized by Microwave irradiation method as a 10% HEMA-PM.
…………………..
Dried under vacuum
at 30 oC for 24 h.
Code, 10%HEMA-PM
Dried for 35 oC, 9h and immersed
in water for 1 day

13. 13 The synthesis route of the (PAM-co-HEMA)/PVA IPN hydrogel
Two step polymerization synthesis
The synthesis route of the (PAM-co-HEMA)/PVA IPN hydroge was shown this Figure. The first step, HEMA and AA were copolymrized using EGDMA as a crosslinger to give p(AA-co-HEMA). Then, p(AA-co-HEMA) crosslink with PVA using GA as a crosslinker to give IPN hydrogel.
Scheme 1. The synthesis route of the (PAM-co-HEMA)/PVA IPN hydrogel.
Y. Yue, X. Sheng and P. Wang, J. Eur. Polym. 45 (2009) 309–315.

14. Equilibrium water content (EWC) and % mass swelling
Experimental 14
Equilibrium water content (EWC) and % mass swelling
Dry gel
weight of swollen hydrogel
Dry hydrogel
%WC = wt . of swollen – wt. of dry polymer x 100
(1)
weighing of dry hydrogel
wt . of swollen polymer
The equilibrium water content (EWC) and % mass swelling of prepared hydrogel were studied. By weighing of dry hydrogel and then, Immersed in distilled water at room temperature. The hydrogels were drawn from water and then, removing the water on the samples surface with filter paper and then weighing of swollen hydrogel. The equilibrium water content (EWC) and % mass swelling of hydrogel were calculate to following equation 1 and equation 2
…………………..
Immersed in distilled water
at room temperature
Mass swelling (%) = [(mt-m0)/m0] x 100
(2)
The hydrogels were drawn from water and then, removing the water on the samples surface with filter paper

15. Results and discussion 15
Infrared spectra analysis
The FT-IR spectra of both samples present the same characteristic peaks.
Absorption band
C-H, cm-1
O-H and N-H, cm-1
C=O, cm-1
C-O, 1078 cm-1
The FT-IR spectroscopy is used to confirm the compositions in the hydrogel samples. Fig. 1 showed the absorption spectrum of 10% HEMA-PM and 10% HEMA hydrogel. The FT-IR spectra of both samples present the same characteristic peaks. FT-IR results showed the characteristic absorption band at cm-1, which related to the stretching vibration of C-H on the backbone. The absorption band at 3382 cm-1 can be attributed to the characteristic peak of O-H and N-H. At 1670 cm-1 and 1078 cm-1 present C=O and C-O groups. As a result, it can be concluded that the (PAM-co-HEMA)/PVA IPN synthesized by microwave irradiation method was successfully prepared
Figure 2. FTIR spectra of (PAM-co-HEMA)/PVA IPN hydrogels

16. Results and discussion 16
SEM photograph
(a)
(b)
Fig. 2. Show the morphology of the (PAM-co-HEMA)/PVA IPN hydrogels. It can be seen that the microstructure of hydrogels are three-dimensional networks having proses and well organized nooks in the surface of hydrogels. Thus, the natures of the pore/slit of the hydrogels render the hydrogels can be absorb and retain water within the structure.
Figure 3. SEM photograph of (a)10% HEMA-PM and (b) 10% HEMA hydrogels.

17. Results and discussion 17
Comparison the adsorption behavior of 10% HEMA and 10% HEMA-PM
Equilibrium swelling ratio
Mass swelling
(a)
(b)
Figure 3a and 3b compared the adsorption behavior of the quilibrium swelling ratio and mass swelling on hydrogels, synthesized by conventional method and microwave irradiation method. In Figure 3a, the samples show similar swelling behavior and fast to equilibrium for 6 min. It can be found that, 10%HEMA-PM can r quickly absorb wate and reaches to equilibrium faster than 10%HEMA. The mass swelling curves of the hydrogel samples are shown in Fig. 3b. The percentage swellings of the samples were higher than 600%. As shown in Fig 3b, the mass swelling of 10% HEMA is slightly higher than that 10% HEMA-PM. Because the hydrogel prepared by microwave irradiation exhibited more crosslinked networks than hydrogel prepared by conventional methods. Therefore, the ability to absorb water of the 10% HEMA-PM hydrogel was decreased. However, the hydrogel prepared by microwave irradiation has good mechanical properties
And then, Figure 4 is shown the characteristics of the hydrogel before and after to absorb water. It is found that, after adsorped water, the hydrogel is larger in size
Figure 4. The swelling behavior (a) equilibrium swelling
ratio (b) % mass swelling of the hydrogel samples.
Figure 5. The characteristics of the hydrogel
before and after to absorb water.
Before
After

18. Conclusions 18
The hydrogel prepared by one-pot microwave irradiation method can greatly shorten the reaction time, comparing with the hydrogel synthesized by conventional method.
The FT-IR analysis confirms the compositions of hydrogel in the IPN networks.
SEM photographs exhibited the microstructure of the IPN hydrogel films.
The hydrogel prepared by microwave irradiation had swelling ratio higher than 600%.
The percentage swelling of hydrogel synthesis by microwave irradiation has slightly lower than that of hydrogel prepared by conventional method.

19. Laboratory of Advanced Polymers for Energy and Biomedical
Acknowledgements
Associate. Prof. Dr. Sayant Saengsuwan
Center of Excellence for Innovation in Chemistry (PERCH-CIC)
National Research Council of Thailand (NRCT)
Laboratory of Advanced Polymers for Energy and Biomedical
Applications (LAPEBA), Department of Chemistry , Faculty of Science
Ubon Ratchathani University
In the finally, i would like to thanks for…my advisor ……Assist. Prof. Sayant Saengsuwan…….
And thanks for…funding research the center of Excellence for Innovation in Chemistry (PERCH-CIC), the national Research Council of Thailand (NRCT), Ubon Ratchathani University, Ubon Ratchathani, Thailand.

20. Mechanism of P(AM-co-HEMA)/PVA IPN films
Initiation
Propagation

21. Termination (Coupling)
Mechanism of P(AM-co-HEMA)/PVA IPN films
Termination (Coupling)

22. Mechanism of P(AM-co-HEMA)/PVA IPN films
PHEMA .
EGDMA
PAM .
Network of P(HEMA-co-AM)

23. Mechanism of P(AM-co-HEMA)/PVA IPN films

24. Mechanism of P(AM-co-HEMA)/PVA IPN filmsGA GA
PHEMA
PVA
PHEMA
PVA

25. The feed composition used for the polymerization.
Symbol
HEMA(g)
AAm(g)
PVA
(g)
H2O(g)
EGDMA (μL)
TMEDA
(μl)
APS (ml)
GA (μl)
HCL (μl)
90%
HEMA
2.25
0.25
2.5 95
100.19
109.59
1.45
55.30
52.96
70%
1.75
0.75
115.57
126.40
1.67
50%
1.25
130.94
143.22
1.90
30%
146.32
160.03
2.12
10%
161.69
176.84
2.35
The crosslinker (EGDMA) : 2.5 % molar to total monomer
GA : wt% in weight of PVA
Ammonium persulfate (APS) : 3.5 mol% to total monomer
N,N,N,N’-tetramethylethylen diamine (TMEDA) : 3.5 mol% to total monomer