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”

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

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. 36 (2000 ) 393-399.

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. 2009. Scientific Research and Essay. 3 11. (2009 ) 1175-1183.

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)

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.

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

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.

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.

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 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

Dried for 35 oC, 9h and immersed 12 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 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.

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

Results and discussion 15 Infrared spectra analysis The FT-IR spectra of both samples present the same characteristic peaks. Absorption band C-H, 3000-2840 cm-1 O-H and N-H, 3382 cm-1 C=O, 1670 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 3000-2840 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

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.

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

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.

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.

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

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

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

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

Mechanism of P(AM-co-HEMA)/PVA IPN films GA GA PHEMA PVA PHEMA PVA

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 : 2.5 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