3D Architectured Poly(acrylamide-co-azomethine-co-acrylic acid) Cogel Synthesis, Characterization and Salinity Profile PDF

RESEARCH ARTICLE 1 Department of Chemistry, M.S.G. College, Malegaon, Savitribai Phule Pune University, Nashik 423105, Maharashtra, India 2 Shiva Pharmachem Pvt. Ltd., Luna, Tal-Padra, Vadodara 391440, Gujrat, India 3 Department of Chemistry, Rashtrant Tukadoji Maharaj Nagpur University, Nagp...

RESEARCH ARTICLE 1 Department of Chemistry, M.S.G. College, Malegaon, Savitribai Phule Pune University, Nashik 423105, Maharashtra, India 2 Shiva Pharmachem Pvt. Ltd., Luna, Tal-Padra, Vadodara 391440, Gujrat, India 3 Department of Chemistry, Rashtrant Tukadoji Maharaj Nagpur University, Nagpur 440033, Maharashtra, India Introduction trends are also work for combining the properties of Super water-absorbent polymers are the most advance organic and inorganic moieties with high surface areas and category of hydrogels that can define as cross-linked pore volumes offers endless possibilities to design macromolecular networks that can absorb a large amount materials adapted to a wide range of advanced of water or solvent. However, during the absorption applications. This type of advance material can be process, they retain their physical appearance by not prepared by number of technologies such as linking getting dissolved when brought into contact with water monomers, ionizing radiation, or physical interactions. These hydrogels are highly hydrophilic, non-toxic, such as entanglements, electrostatics, and crystallite biodegradable, and biocompatible [1,2]. Polymeric formation. The mining industry is one of the growing hydrogels are of great interest for biomaterials industry which utilize densified tailings densification applications on account of their biocompatibility. using thickeners sometimes proves unable to achieve the These are amongst the most attractive classes of "soft design target solids mass concentration. To overcome matters" with several established and many more possible these, superabsorbent polymers (SAPs) seems to represent applications. Conversely, swelling is limited to rubber-like a promising alternative, owing to densified tailings higher behavior due to the presence of crosslink or strong water absorbent capacity. Our research group D. S. physical interactions among the polymeric chains. Raghuvanshi et. al., synthesized "3D architectured Few research groups have conducted studies on Schiff polyazomethine gel" and determined its complexion polymers, and a great diversity of structures is obtained ability. Still, these materials have very little stability, so to. Schiff base polymers like azomethine are high- overcome this limitation, we integrate cogel of performance polymers presenting good mechanical polyazomethine and poly(acrylamide-co-acrylic acid) strength and semiconducting properties [5,6]. However, [P(AM-co-AA)] [11,12]. poor solubility of high-molecular-weight polymers makes The present context is mainly focusing on the it difficult for versatile applications and the determination synthesis of aliphatic 3D-structured azomethine polymer of their structural and macromolecular features. as per literature. Accordingly reports, this polyazomethine Most of the material scientist’s research groups are gel gets decompose after 5°C hence by intermolecular engage to develop valuable products like waste water interactions with P(AM-co-AA)], the stability of treatments and its environmental aspects. Recent polyazomethine is an increase, which is confirmed by  Advanced Materials Proceedings advance thermal techniques. The swelling capacity of Analytical methods P(AM-co-AA) and co-gel are studied by the addition of The samples are tested with infrared spectra on a different saline solutions, including monovalent, divalent, Shimadzu FT-IR 8400 frequency range from 400 to and trivalent salts. Its applications may extend in marine 4000 cm-1 using KBr flakes. The scanning of the sample water industries as a basis for antifouling coating, waste is done at a rate of 28 times before the final recording of water treatment, and even in the medical field. spectra. Thermal Gravimetric Analysis is executed on Experimental TGA-4000 (Perkin Elmer) with the Nitrogen flow rate of 20 ml/minute and temperature increment rate of Materials/chemicals details 15°C/minute. Differential Scanning Calorimetric analysis Acrylamide (98%) is obtained from Spetrochem Pvt. Ltd., is executed on DSC-4000 (Perkin Elmer) with the Mumbai, India. Glyoxal (40%) is purchased from Sigma Nitrogen flow rate of 20 ml/minute and temperature Aldrich Chemicals. Triethylenetetramine (97%) (TETA) is increment rate of 10°C/minute. FE-SEM images are taken purchased from Sisco Laboratory, Mumbai, India. Acrylic on a Hitachi S4800 instrument after gold plating applied acid (98%), Potassium persulphate (KPS) was purchased with the help of a Hitachi Ion Sputter E1010 instrument. from SD Fine Chemicals, Mumbai, India. Results and discussion Material synthesis /reactions FT-IR analysis Scheme 1: Synthesis of Polyazomethine Gel The infrared spectra of P(AM-co-AA) is given in As per the literature , 10 mmol of glyoxal (40%) was Fig. 2(a), The midrange peak in the range of 3633-3451 subjected to slow stirring using a magnetic stirrer. Its cm-1 are results due to –NH2 from acrylamide, presence of temperature was brought down to 0-5°C. The gradual water in hydrogel and acidic –OH of the polymer. The addition of (10 mmol) TETA into chilled glyoxal was C-H stretching band is confirmed by the presence of a executed through the addition funnel. In addition, an peak at 2950cm-1 due to asymmetric stretching vibrations exothermic reaction occurs; so, the rate was adjusted such of –CH2 groups in the polymer. Amide carbonyl is seen at that the reaction temperature must not reach above the 1683 cm-1, The peaks found in between 800- 400 cm-1 are 5 °C; otherwise, the product gets degraded. due to bending occurs from NH and OH groups [12,13]. Scheme 2: Synthesis of Cogel FT-IR analysis is evident for the proper synthesis of polyazomethine shown in Fig. 2(b). It shows a prominent Cogels are prepared by free-radical polymerization of peak at 1673 cm-1 for C=N stretching. The broad peak at acrylamide and acrylic acid in water (Fig. 1). Acrylamide 3067 cm-1 occurred due to the presence of secondary (5g) is dissolved in 20 mL of double distilled water in amine (N-H stretching) in the polymer repeating units. 250mL three-neck flask equipped with a stirrer, a The peak at 2905 cm-1 is for the methylene C-H stretching. condenser, and a thermometer. Acrylic acid (2mL) is added to the reaction mixture and stirred at room temperature for 10 min. polyazomethine gel is added to the reaction mixture when the temperature of reaction mass goes up to the 64°C with stirring. Potassium persulphate (0.2g) is added as a radical initiator into reaction mass for polymerization at constant stirring. The resulting cogel was cool at room temperature. Fig. 2. Infrared spectra of (a) P(AM-co-AA) (b) Polyazomethine and (c) Cogel. The infrared spectra of cogel are given in Fig. 2(c), and from this spectra, we can see that the C-H stretching Fig. 1. Scheme for cogel synthesis. band at 2950 cm-1 due to asymmetric stretching vibrations  Advanced Materials Proceedings of –CH2 groups in co-gel. Amide carbonyl or C=N water of crystallization introduced through 40% glyoxal. stretching is seen at 1683 cm-1, which is as per native During the first step degradation of the polymer, 20% polymers. The bands found in between 800- 400 cm-1 are weight loss is observed. The second step degradation starts due to bending occurs from NH and OH groups. from 220°C up to 470°C, due to breaking of polymer linkages and generation small organic molecules. Third Morphological Analysis (FE-SEM) step degradation at 470°C, which renders up to 700°C, One of the most important properties that must be which is because of the total decomposition of materials considered when studying hydrogel is its microstructure into carbon residue and gasses. Nearly 40% of weight loss morphology. Fig. 3(a) shows the secondary electron observed during the second step degradation of polymer images of P(AM-co-AA) in the water-saturated state are while again 40% weight loss observed during third step study. This finding verifies that the synthesized polymer degradation. structure of P(AM-co-AA) has a porous structure with an effective pore size 150-250 nm range. It is supposed that these pores are a region of water permeation and interaction sites between external stimuli and the hydrophilic groups of the gel. These pores are produced from water evaporation at the time of hydrogel synthesis. The sample morphological is studied with the help of FE-SEM images, as shown in Fig. 3(b) are showing the sheets like structures, which are separated by an average distance of 1.5 μm. Thus, this is evident that the polymer was having three dimensional lamellar layered like morphology. The layers can be easily observed in an image. This can be concluded that the chains grow straight without any kind of branching in it. The smooth structure of cogel is presented in Fig. 3(c). It was clearly observed that the cogel exhibited homogeneous smooth with a layer like structure, resulting Fig. 4. TGA curves of P(AM-co-AA), Polyazomethine (PA) and Cogel. in higher swelling behaviour. It is supposed that these Thermal gravimetric analysis is used for the morphologies where the region of water permeation and recognition and thermal stability of gel. The cogel interaction sites between external stimuli and the underwent weight loss in three stages and 97.393% of its hydrophilic groups of the gel. original weight loss at 650°C. The first degradation due to dehydration of water molecule, the second degradation is due to the decomposition of the acrylic polymeric chain, and third stage degradation is due to decomposition azomethine linkage present in the gel. Cogel show three- step degradation in-between temperature 20 to 650°C in which the first degradation occurs at a temperature between 29 to 200°C at this maximum temperature Fig. 3. FE-SEM images of (a) P(AM-co-AA) (b) Polyazomethine and (c) Cogel. amount of polymer chain get break and 68.88% weight loss occurs, Second step degradation starts from 200 to 480°C near about 15.57% weight loss due to degradation Thermo gravimetric Analysis (TGA) of residues, Third step degradation starts from 480 to Thermogravimetric analysis (TGA) has been done on 620°C concerning 12.931% weight loss occurs. samples to identify the changes in weight percent concerning temperature change and given in Fig. 4. TGA Differential Scanning Calorimetry (DSC) was performed on P(AM-co-AA), polyazomethine, and The DSC curves for polyazomethine, P(AM-co-AA), and cogel. TGA results plotted in Fig. 4 in the temperature cogel are represented in Fig. 5. The curve of P(AM-co- range of 50 to 850°C indicates P(AM-co-AA) exhibited AA) showed a characteristic endothermic peak at 240°C, weight losses at 30 to 300°C due to loss of water, second corresponding to its decomposition. In comparison, degradation due to decomposition of amide linkage at 300 polyazomethine showed the exothermic peak at 150°C for to 490°C, remaining 29.116% weight loss at 490 to 600°C evaporation of water crystallization introduced through which are result of the degradation of acrylic acid group in 40% glyoxal. As regards the analysis of cogel, the peak polymer. Thermal Gravimetric curves are showing for the decomposition of P(AM-co-AA) shifted to 180°C, three-step degradation of polyazomethine comprising and peak for polyazomethine to 130 °C indicated there is TETA as a repeating unit. The first step degradation starts the presence of interactions between polyazomethine and from 60°C up to ~200°C due to the evaporation of the P(AM-co-AA). This concludes lowering of melting of  Advanced Materials Proceedings P(AM-co-AA) in the complex state may be due to a Conclusion variation of intermolecular forces between P(AM-co-AA) by polyazomethine and introduces intermolecular This innovation is straight forward, and efficient interactions, which also supports the formation of cogel synthetic protocol for cogel formation responds without. any environmental hazard. The present study demonstrated the formation of cogel between P(AM-co- AA) and polyazomethin. Cogel of P(AM-co-AA) and polyazomethine showed responsive behaviour concerning the salt solution presenting the excellent potential of the application as devices for the controlled release of solutes. The results indicate that the order of water uptake decreases with increases in valency of salts. Hence, simple operations and eco-friendly protocol for the synthesis of cogel is developed. Acknowledgements An author acknowledges the School of Chemical Sciences, North Maharashtra University, Jalgaon, and DST-FIRST for financial support. We are sincere, thanks to Dr. A. P. Hire and also Principal MSG College Malegaon, Head Department of Chemistry, MSG College Malegaon for providing infrastructure and laboratory facilities. Conflicts of interest Fig. 5. DSC curves of P(AM-co-AA), Polyazomethine (PA) and Cogel. There are no conflicts to declare. Effect of salt solution on water absorbency Keywords The influence of ions (cations and anions) on the swelling Poly(acrylamide-co-azomethine-co-acrylic acid), polyazomethine, swelling behaviour, salinity profile. ability of cogel was experienced by the addition of different saline solutions, including monovalent (NaCl), References divalent (CaCl2), and trivalent (AlCl3) solutions at the rate 1. Ahmed E. M.; J. Adv. Res., 2015, 6, 121. of 0.15 mol L-1 at 25°C. Multivalent cations can neutralize 2. Shivam P.; Int. Res. J. of Science & Engineering, 2016, 4, 26. several charges inside the cogel by complex formation 3. Del Valle E. M.; Process Biochemistry, 2004, 39, 1046. 4. Yang, Q.; Adrus, N.; Tomicki, F.; Ulbricht, M.; J. Mater. Chem., with hydroxyl and amide groups, including intramolecular 2011, 21, 2811. and intermolecular interactions leading to an increased 5. Li, L.; Li, Z; Wang, K.; Zhao, S.; Feng, J.; Li, J.; et al J. Agric. ionic crosslinking degree and consequently loss of Food Chem., 2014, 62, 11088. swelling. Therefore, the absorbency for the cogel in 6. Qin, W.; Long, S.; Panunzio, M.; Biondi, S.; Molecules, 2013, 18, 12289. studied salt solutions is in order of monovalent> 7. Choudhary, M.; et al. Green Materials for Waste water Treatment. divalent>trivalent. From Fig. 6, it can be concluded that Springer, Cham, 2020, 12. the higher the cation charge, the smaller is the swelling 8. Wang, Y.; Alauzun, J. G. & Mutin, P. H.; Chem. Mater., 2020, 32, value. Consequently, the crosslinking density of the 2918. 9. Ahmed, E. M.; J. Adv. Res., 2015, 6, 121. network increases while water absorption capacity 10. Sahi, A.; El Mahboub K.; Belem, T.; Maqsoud, A.; Mbonimpa M.; decreases [15,16]. Minerals, 2019, 9, 785. 11. Raghuvanshi, D. S.; Shirsath, N. B.; Mahulikar, P. P.; Meshram, J. S.; Bull. Mater. Sci., 2018, 41, 44. 12. Shirsath, N. B.; Gite, V. V.; Meshram, J. S.; Russ. J. Appl. Chem., 2016, 89, 1893. 13. Mei, Z.; Chung, DDL; Thermochim Acta, 2001, 369, 93. 14. Bertolasi, V.; Gilli, P.; Gilli, G.; Cryst Growth Des., 2011, 11, 2735. 15. Gurdag, G., Yasar, M.; Gurkaynak, M. A.; J. Appl. Polym. Sci., 1997, 66, 934. 16. Shirsath, N. B.; Gite, V. V.; Meshram, J. S.; Mod. Org. Chem. Res., 2017, 2, 66. Fig. 6. Swelling ability of P(AM-co-AA) and Cogel.  Advanced Materials Proceedings Authors biography Graphical Abstract Prof. Jyotsna Meshram is presently heading the Department of Chemistry at Rashtrasant Tukdoji Maharaj Nagpur University, Nagpur. She had all most 25 year teaching and research experience. She was the member of several national committee bodies. She had published more than 120 research articles in national and internationally reputed journals including RSC Advances, Journal of Toxicology and Luminescence etc. More than 20 students had persude their doctoral degree under her guidance. Dr. Nandkishor B. Shirsath serves as an Assistant Professor at the Department of Chemistry, M.S.G. College, Malegaon, Dist. Nashik under Pune University. Dr. Shirsath has been actively engaged in material science research, especially composite, dendrimers, polymer degradation, fly ash, hydrogels, and ionic liquids. With this he has number of research paper at National and International reputed journals and life member of SMC, BARC and ISC. He Handle critical challenges in medical, agricultural, energy, and environmental issues realized by the integration of artificial intelligence and smart strategies.. Dr. Devendra Raghuvanshi is currently working as Team Leader, Research and Development Department, Shiva Pharmachem Pvt. Ltd., Luna, Padra, Vadodara. He has published 5 papers and 1 book chapter in internationally and nationally reputed journals. He has 4 year institutional and 4.5 year industrial research experience. He had presented in more than 12 national/international conferences and workshops and achieved 4 awards on credit including RSC Fellowship Awards. He has delivered lectures and taken practicles of post graduate students. Some lectures are available online on his personal you tube channel “Dr. Devendra Raghuvanshi”. https://www.youtube.com/channel/UCCGQv7lXhVsKQVNFOYb7pJA? view_as=subscriber