A Comparative Thermal stability Study of N-(4-Nitropheny) Maleimide and N-(2, 4-di-nitrophenyl) maleimide with Methylacrylate

Abstract

In this article two type of monomers were synthesize, having different position on benzene ring one present on 4th position and second present on 2,4 position. Monomers were prepared by Maleic anhydride reaction with 2,4 dinitro aniline and 4 nitro aniline and obtained 4-Nitropheny Maleimide and 2,4-Didinitrophenylmaleimide copolymerized with Methylacrylate. Investigated a comparative study in between and what effect will come with thermal stability of the synthesis polymers. Free radical initiator AIBN and BPO were used of the polymerization and percentage yield calculated in THF and DMF solvent system under the identical conditions. Polymerization reaction proceed at different time (12, 24, 36) hours. Prepared homopolymer and copolymer were characterized by FTIR and 1H-NMR. The thermal stability and percentage degradation of the polymer were recorded by TGA Techniques. Percentage yield were obtained with given time hours and using free radical initiator and solvent systems. Synthesis polymers and their PDI values obtained range 1.5 to 10(Mw/Mn), it indicate that polymerization proceed via radical polymerization. Shape of the polymer in given solution were determined by Kuhan Mark Equations. Homopolymer shows unperturbed condition and copolymer present in rigid rods. Reduced viscosity and Intrinsic viscosity determined by the using Ubbelhod viscometer. Number average and weight average molecular weight were determined by the Gel permeation chromatography. Different feed mole ratios and percent yield were reported.

Introduction

I. INTRODUCTION

At present time polymer have vast demand in daily life and polymers which are having N-Phenylmaleimide in their backbones more useful and most important useful of polymer in medical sciences ,aerospace.  mechanical properties, dielectric properties, thermal stability and outstanding bonding ability, epoxy resin has been widely applied as coating, insulation materials, etc, in the electronic, electrical, mechanical manufacturing, aerospace and other fields, especially  polymers used  in  circuit board (PCB), the demand on the thermal resistance of insulation material becomes severe [1,2]. In recent study observed  Styrene and maleic anhydride copolymer give excellent thermal resistance property [3,4] . It is known that N-phenyl maleimide (N-PMI) has high thermal resistance [5]. recently developed one-pot post-polymerization modification reactions using p-maleimidophenyl isocyanate (PMPI) as a modification reagent to introduce maleimide moieties into polymers with hydroxy groups and studied the polymerization reactions between the introduced N-aryl MA groups and thiol groups[6] N-Substituted Phenyl maleimide are interesting monomers for making transparent thermally stable polymeric materials [7-13]. Recently we are published 4-Nitro Phenylmaleimide copolymerized with Acrylonitrile and Ethyl acrylate . In this continuations  we are  interesting about the 4-Nitrophenyl maleimide and 2,4 Dinitrophenyl maleimide copolymerized with Methylacrylte (MA). Investigated comparative thermal stability, determined by the TGA Techniques and characterized by FTIR and 1HNMR.  

II. EXPERIMENTAL

A. Materials

Methylacrylate (CDH) was shaken two to three times with 5% NaOH to eliminate hydroquinone inhibitor, dried over anhydrous CaCl2 for 6 hours and distilled [14]. The head and tail fractions were discarded. AIBN (2,2_-azobis–isobutironitrile (spectorchem.)) was recrystallized twice from methanol prior to use. BPO (benzoyl peroxide CDH) was used as received. THF was purified by distillation after being refluxed for 2 h in the presence of sodium. Dioxane and DMSO were used after distillation. DMF and methanol used in the present work were of analytical grade and were used as received.

B. Measurements

1H-NMR spectra of monomer and polymer samples were taken in DMSO-d6 on a Bruker DPX-200/DPX-300 spectrometer at 200/300 MHz. The internal reference used was TMS. FT-IR spectra of the monomer and polymer sample were recorded on a Shimadzu 8201 PC (4000-400 cm-1) FT-IR spectrometer, using KBr pellet technique. The viscosity measurements were carried out in DMF at 30±0.2 °C, using an Ubbelohde suspended level viscometer. Elemental analysis was made on Carlo Erba Model NA 500 series analyzer. The thermograms in air were obtained on a Mettler TA-3000 system, at a heating rate of 10 °C/min

C. Methods

Preparation  N-(4-Nitrophenyl) maleimide (MNPMI) : 4-Nitro aniline (13.8 gm for 0.1mol) and 9.8 gm maleic anhydride were taken in 30 ml DMF. The reaction mixture was stirred for three hours at 25°C. The reaction mixture was poured in crushed ice. Yellow solid precipitate was obtained, then filtered and dried under vacuum. It was recrystallized from methanol to obtained pure N-(4-Nitrophenyl) maleamic acid. Cyclodehydration of the 4-Nitromaleamic acid, this solution treated  with conc. H2SO4 and P2O5 and  stirred for three hours at 65°C. Then the solution poured in crushed ice or cooled water, obtained to yellow solid precipitate filtered and washed with water and dried.N-(4-Nitrophenyl) maleimide was recrystallized from ethyl alcohol solvent. The yield was 65%, m.p. 120°C.

D. Preparation  N-(2,4-Dinitrophenyl) maleimide (OPNPMI)

Equal amount of 2,4 Dinitrophenyl maleimide  and equal amount  maleic anhydride were taken in 30 ml DMF. The reaction mixture was stirred for three hours at 25°C. The reaction mixture was poured in crushed ice. Yellow solid precipitate was obtained, then filtered and dried under vacuum. Cyclodehydration of the 2,4-diNitrophenylmaleamic acid, treated  with conc. H2SO4 and P2O5 and  stirred for three hours at 65°C. Then the solution poured in crushed ice or cooled water, obtained to yellow solid product.

E. Homopolymerization of N-(4-Nitrophenyl) maleimide (HPNPMI)

4-Nitrophenylmaleimide (2.18 gm, 0.01 mol) were taken in 30 ml THF solvent in round bottom flask with fitted reflux condenser. Free radical 20 mg AIBN was added and the reaction mixture was refluxed on heating mental at 65°C for 12, 24, 36 and 48 hours. Product was occurred 32.33% for 24 hours. Prepared polymer  was separated  in excess amount of methanol water mixture. It was dried under vacuum at 55°C then kept under dedicator free from moisture.

F. Homopolymerization of N-(2,4 Dinitrophenyl) Maleimide (HOPNPMI)

2, 4-Dinitrophenylmaleimide ( 0.01 mol) were taken in 30 ml THF solvent in round bottom flask with fitted reflux condenser. Free radical 20 mg AIBN was added and the reaction mixture was refluxed on heating mental at 65°C for 12, 24, 36 and 48 hours. Product was obtained. Prepared polymer  was separated  in excess amount of methanol water mixture. It was dried under vacuum at 55°C then kept under dedicator free from moisture.

G. Copolymerization of N-(2,4-Dinitrophenyl) Maleimide with Methylacrylate( OPNPMCMA)

Equal amount of 2,4-Nitrophenylmaleimide  and Methylacrylate in 30 ml THF solvent were taken in a round bottom flask. The reaction was carried out at 65°C for 12, 24 ,36 hours. Copolymer samples were isolated in water containing 20 % methanol. The copolymer were purified by first dissolving in THF and then, reprecipitating in excess quantity of methanol water mixture. The precipitated copolymers were washed with methanol several times and dried at 60°C under vacuum.

H. Copolymerization of N-(4-Nitrophenyl) maleimide with Methylacrylate (PNPMCMA)

Equal amount of 4-Nitrophenylmaleimide  and Methylacrylate in 30 ml THF solvent were taken in a round bottom flask. The reaction was carried out at 65°C for 12, 24 ,36 hours. Copolymer samples were isolated in water containing 20 % methanol. The copolymer were purified by first dissolving in THF and then, reprecipitating in excess quantity of methanol water mixture. The precipitated copolymers were washed with methanol several times and dried at 60°C under vacuum.

III. RESULTS AND DISCUSSION

A. PNPMI

FTIR spectra observed at 3091.3,2980.8 (aromatic and alkene C-H stretch), 1797 and 1708 ( C=O), 1634(CH=CH, alkene), 1564 1456 (C=C, aromatic) , 1335,1504 ( –NO2), 967 (CH=CH), 856(1,4 disubstituted benzene) these are consistent with the structure of PNPMI. 1H-NMR: (CH=CH) protons at d 6.82 (s) ppm, Aromatic protons at d7.13-7.15 (d) ppm; two aromatic proton (m-group in phenyl ring) at d7.63-7.64 (d) ppm [15-20] .

B. HPNPMI

3088 (C-H aromatic), 2981 (C-H stretch alkene), 1778, 1715( C=O) 1614, 1651, 1563, 1444, 1596 (C=C stretch aromatic), 1504, 1331 ( Ar-NO2 ), 1255 (asymmetric C-O-C stretch), 1110, 1168 (symmetric C-O-C stretch), 856 (1,4 disubstituted benzene) and 690, 605 (out of plane aromatic ring C=C bend). the 1H–NMR d 7.50–8.08 (d). 2H,at 3.5–4.0 ppm [21-23].

C. PNPMCMA

In fig.1, 3050,3190 (Aromatic,C-H), (CH=CH), 1750, 1790 (C=O), 1548  (-NO2 group) 1461.9 (C-H band, –CH2), 1380 ( C-N, Stretching of maleimide),1189 (C-O-C), 1540,1548 (-NO2), 832 (1,2-disubstituted benzene) and 780.3,850 cm–1 (out of plane C-H band of benzene ring), and 630 (aromatic ring C=C band). 1H-NMR of PNPMCMA, In Fig.2, d values from 7.5 to 8.1 due to present of phenyl ring protons and a signal of showing d at 4.0 present of MA, d values obtained in 3.3 to 3.5 ppm, polymerization precede via single bond.

D. OPNPMCMA

 3070,3200 (Aromatic,C-H) 1740, 1800 (C=O), 1570  (-NO2 group) 1484 (C-H band, –CH2), 1320,1380 ( C-N, Stretching of maleimide), 1100 (C-O-C), 1531 (-NO2), 890 (1,2-disubstituted benzene) and 700,750 cm–1 (out of plane C-H band of benzene ring), and 670  (aromatic ring C=C band). 1H-NMR of PNPMCAA, In Fig.3, d values from 7.5 to 8.1 due to present of phenyl ring and a signal of showing d at 4.0 present of MA, d values obtained in 3.3 to 3.5ppm.

E. Effect of time on yield

Percentage yield were obtained at different time hours and any polymeric material very useful for industries purpose and percentage yield was given in table. 1 and from the table we are observed that percentage yield was increases with time hours.

Table 1. Percentage Yield of Homopolymer and copolymers given in table with respect to time Hours.

F. Effect of solvent and Initiator on percentage yield

Percentage yield of synthesis polymer are calculated with respect using Free radical AIBN and BPO and results are summarized in table 2. Indicate that the percent yield in the AIBN-DMF system is more suitable as the comparable BPO-DMF solvent system. AIBN-DMF system gives higher yield.

Table    2. Shows the result of percentage yield in DMF-AIBN and DMF-BPO Solvent system

G. Intrinsic viscosity

 Intrinsic viscosity determined by Ubbelohde suspended   viscometer. Intrinsic viscosity depends on molecular weight as well as on the size of  the polymer coil in a given  solution. it is a measure  of hydrodynamic volume. Molecular weight of synthesis compounds determined by the Gel Permeation Chromatography and relation find out in between molar mass and intrinsic viscosity. The relation between the molecular weight and intrinsic viscosity of polyvinyl alcohol observed [21] . The viscosity measurements were carried out with an Ubbelohde suspended level type viscometer[22].From the flow time of solution (t) and solvent t0, the specific viscosity (hsp) was evaluated by the following relationship.

The intrinsic viscosity [h] was obtained from the plots of reduced viscosity versus concentration by extrapolating the curve at c ® 0. Intrinsic viscosity (h) of homopolymers and copolymers are summarized in table.  3 and 4

J. Solubility Behavior of  Homopolymer and copolymer

Synthesis homopolymer and Copolymers were  finely grounded and polymer powder insert and  placed into test tube and two to three ml solvent was added and stirred at 30C. same procedure repeat again and again for each sample. Solvents were taken as follows THF,DMF,DMSO,Benzene.Methylacetate,,1,4Dioxane,Xylene,dichloromethane,2Butanol,cyclohexanon,water,methanol and carbon tetrachloride. Knowing about information very important for any industrial purpose because today’s times a lot of paints made by the plastic coated materials. Solubility of any polymeric materials depends upon the composition of polymer structure. Solubility of homopolymer is less than copolymer while always is not  same . Result of Solubility is summarized in table. 7

IV. ACKNOWLEDGEMENT

We are thankful to CDRI Luck now and SICART Vallabh-Vidhyanagar for analysis work. Authors Shiv Narayan Paliwal and Suresh Meena is thankful to UGC (RGNSF), DST FIST ,New Delhi or financial assistance.

Conclusion

Synthesis homopolymer and copolymer shows the excellent solubility in THF,DMF ,DMSO, Chloroform .Ethyl acetate and solubility of any polymeric materials depends on the composition like as texture and length ,molecular weight, Intrinsic viscosity. It is observed that polymerization reactions completed via radical polymerization this is approved by the Polydispersity index. Copolymer shows highly molecular weight more than of homopolymer it is due to copolymer having both are unit. Weight average and number average molecular weight determined by the Gel permeation chromatography. Polymers exhibit highly thermal stability due to present of imide ring and Homopolymer shows highly thermal stability than copolymers because homopolymer contain only single unit in their backbones.

References

[1] Lin, L.L., Ho, T.H. & Wang, C.S., Synthesis of novel trifunctional epoxy resins and their modification with polydimethylsiloxane for electric application, Polymer, 38, pp.1997-2003, 1997. [2] Watanabe, F., Mizoguchi, T. & Iwafune, M., Polymer composition for electrical part material, US Patent 5,502,098, 1996. [3] Chernikova, E., Terpugova, P., Bui, C. & Charleux, B., Effect of comonomer composition on the controlled free-radical copolymerization of styrene and maleic anhydride by RAFT, Polymer, 44, pp.4101-4107, 2003. [4] Tawfik, M.E. & Elsabee, M.Z., Preparation and characterization of polyester based on bis-(2-hydroxypropyl terephthalate, J Polym Res, 9, pp.129-133, 2002. 1114 [5] Thamizharasi, S. & Reddy, B.S.R., Copolymerization of N-substituted maleimide with alkyl acrylate and its industrial applications, J Appl Polym Sci, 80, pp.1870-1879, 2001. [6] R. Takashima, J. Kida, D. Aoki and H. Otsuka, J. Polym. Sci., Part A: Polym. Chem., 2019, 57, 2396–2406. [7] Doi T, Akimoto A, Matsumoto A, Oki Y, Otsu T. Alternating copolymerization of N-(alkyl-substituted phenyl)maleimides with isobutene and thermal properties of the resulting copolymers. J Polym Sci, Part A: Polym Chem. 1996;34:2499–505. [8] Hisano M, Takeda K, Takashima T, Jin Z, Shiibashi A, Matsumoto A. Sequence-controlled radical polymerization of N-Substituted maleimides with 1-methylenebenzocycloalkanes and the characterization of the obtained copolymers withexcellent thermal resistance and transparency. Macromolecules 2013;46:7733–44. [9] Suwier DR, Steeman PA, Teerenstra MN, Schellekens MA, Vanhaecht B, Monteiro MJ, Koning CE. Flexibilized Styrene-N-substituted maleimide copolymers with enhanced entanglement density. Macromolecules 2002;35:6210–6. [10] Matsumoto A, Kubota T, Otsu T. Radical polymerization of N-(alkyl-substituted phenyl)maleimides: synthesis of thermally stable polymers soluble in nonpolar solvents. Macromolecules 1990;23:4508–13. [11] Ahn KD, LeeYH, Koo D, II. Synthesis and polymerization of N-(tert-butyloxycarbonyl)maleimide and facile deprotectionof polymer side-chain t-BOC groups. Polymer 1992;33:4851–6. [12] Hill DJ, Shao LY, Pomery PJ, Whittaker AK. The radical homopolymerization of N-phenylmaleimide, N-n- hexylmaleimide and N-cyclohexylmaleimide in tetrahydrofuran. Polymer 2001;42:4791–802. [13] Gacal B, Cianga L, Agag T, Takeichi T, Yagci Y. Synthesis and characterization of maleimide (Co)polymers with pendant benzoxazine groups by photoinduced radical polymerization and their thermal curing. J Polym Sci, Part A: Polym Chem. 2007;45:2774–86 [14] B.L.Hiran. S. K.Meena , B. S. Meena. M.Meena, Thermal Study and Characterization of New Synthesis N-Benzylmaleimide and N- Phynyl Maleimide Polymers, International Journal of Engineering Research & Technology, 8 : 07, 2019. [15] Silverstain R.M.; Bassler G.C. and Morril T.C.; Spectrometric Identification of Organic Compounds, 4th Edn. John Wiley and Sons. Inc. New York (1991). [16] Pyriadi T.M. and Hammad A.S.; Polymer, 37, 5283 (1996). [17] Riddick J.A.; Bunger W.B. and Sakano T.K.; Organic Solvents : Physical Properties and Methods of Purification, Wile Interscience, New York (1980). [18] Pradhan R.T., Misra P.T. and Tripathi S.S, IPCL, Vadodra. [19] Fux and Otto V.; To Macromol, Sci.,Chem. A20 (1), 32 (1983). [20] Searle N.E.; U.S. Patent 2, 444, 536 (E.I. Dupont de Nemours and Co.), 1948. [21] Otsu T., Yasuhara T. and Masumoto A.; J. Macromol. Sci., Chem., A25, 537 (1988). [22] Matsumoto A., Kubota T. and Otsu T.; Macromolecules, 23, 4508 (1990). [23] Nair C.P.R.; Macromolecules, 26, 47 (1993). [24] Ubbelohde, L., Ind. Eng. Chem. Anal. Ed. 9, 85 (1935). [25] G. S. Misra & P. K. Mukherjee., The relation between the molecular weight and intrinsic viscosity of polyvinyl alcoholColloid and Polymer Science volume 258, pages152–155 (1980).

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Copyright © 2023 Suresh Kumar Meena, Sanjeet Singh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.