Maleimide Monomers Research Articles

Synthesis, curing kinetics and processability of a low melting point aliphatic silicon-containing bismaleimide

An aliphatic silicon-containing maleimide monomer 1,1'-((1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1H-pyrrole-2,5-dione) (TBB) with low melting point (56 °C) was successfully synthesized based on maleic anhydride (MA) and 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis(propan-1-amine) (BAT). The structure of TBB monomer was determined by FTIR, 1H NMR and 13C NMR. Meanwhile, the 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis(propan-1-amine) (BAT) and 4,4’-Bismaleimidodiphenylmethane (BDM) monomers were respectively prepared from diallyl bisphenol A (DBA), following a 1:0.87 molar ratio, and named TD resins and BD resins. The curing kinetics, thermal stability and processability of TD resins and BD resins were discussed and compared. The activation energy (E) value of TD resins was 26.2% higher than BD resins, resulting in exothermic peak temperature (TP) of TD resins was higher than BD resins at different heating rates. Compared with BD resins, the crosslinking density (ve) of TD resins was reduced by 93.5%, which effectively destroyed the thermal stability of TD resins. However, TD resins exhibited outstanding processing window of 195.6 °C. The processing window of TD resins was 110.1% wider than that of the BD resins, indicating that the former had excellent processability. Overall, this study has enriched the discussion on the curing kinetics of aliphatic bismaleimide resins and has a positive influence on the design of resins monomer with low melting point.

Antibacterial activity of hydrophobicity modulated cationic polymers with enzyme and pH-responsiveness.

The membrane lipid compositions of prokaryotic and eukaryotic cells are inherently different in many aspects, although some similarities exist in their structure and composition. Therefore, selective targeting of membrane lipids with a compound of therapeutic value, such as an antibacterial copolymer, is often challenging. Hence, developing an ideal copolymer with antibacterial properties demands hydrophobicity/hydrophilicity balance with a high biosafety profile. To integrate hydrophobic/hydrophilic balance and cationic charge in an alternating antibacterial copolymer with enzyme and pH-responsiveness, a lysine appended styrenic monomer was copolymerized with a fatty acid (octanoic acid (OA) or myristic acid (MA)) tethered maleimide monomer via reversible addition-fragmentation chain transfer (RAFT) polymerization. A range of microscopic analyses, including dynamic light scattering (DLS), confirmed the formation of nanoaggregates (size ∼30-40 nm) by these polymers in aqueous solution with positive zeta potential (cationic surface charge). Hydrophobic Nile red (NR) dye was successfully encapsulated in the nanoaggregates, and the in vitro release kinetics of the NR dye were monitored at different pHs and in the presence or absence of esterase/lipase. The in vitro release kinetics of NR revealed ∼85% dye release in the presence of pH 5.5 and lipase, suggesting their suitability for pH/enzyme-triggered therapeutic payload delivery. The standard broth microdilution assay showed significant bactericidal activity against both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria with an MIC50 value <30 μg mL-1. The effect of polymeric nanoaggregates on bacterial morphology and in vitro survival was further confirmed by field emission scanning electron microscopy (FESEM), agar gel disk diffusion assay, and bacterial live/dead cell count. The significantly low hemolytic activity against red blood cells (RBCs) (HC50 >103 μg mL-1) and nontoxic effect on human intestinal epithelial cells (INT 407) (EC50 >500 μg mL-1) ensure that the polymer nanoaggregates are safe for in vivo use and can serve as a potent antibacterial polymer.

One‐Pot Structure‐Controlled Synthesis of Hyperbranched Polymers by a “Latent” Inimer Strategy Based on Diels–Alder Chemistry

AbstractAn efficient “one‐pot” strategy for the structure‐controlled synthesis of hyperbranched polymers (HBPs) based on a “latent” inimer (LI‐Br), containing a furan‐protected maleimide monomer and a haloalkane initiator, is presented. At high temperatures, the “latent” inimer is converted to a “real” inimer after releasing maleimide (MI) via a retro‐Diels–Alder (r‐DA) reaction and then copolymerized with methyl methacrylate by self‐condensing vinyl copolymerization. Due to the dynamic characteristic of the r‐DA reaction, the release of naked MI and the subsequent copolymerization can be regulated by the temperature or stereochemistry of Diels–Alder (DA) adducts. Thus, the “one‐pot” structure‐controlled synthesis of HBPs with various degrees of branching was achieved. By further implementation of a programmable temperature change, some valuable hyperbranched topologies such as star‐shaped and long‐chain hyperbranched polymers can be constructed avoiding sophisticated synthetic routes.

One-Pot Structure-Controlled Synthesis of Hyperbranched Polymers by a "Latent" Inimer Strategy Based on Diels-Alder Chemistry.

An efficient "one-pot" strategy for the structure-controlled synthesis of hyperbranched polymers (HBPs) based on a "latent" inimer (LI-Br), containing a furan-protected maleimide monomer and a haloalkane initiator, is presented. At high temperatures, the "latent" inimer is converted to a "real" inimer after releasing maleimide (MI) via a retro-Diels-Alder (r-DA) reaction and then copolymerized with methyl methacrylate by self-condensing vinyl copolymerization. Due to the dynamic characteristic of the r-DA reaction, the release of naked MI and the subsequent copolymerization can be regulated by the temperature or stereochemistry of Diels-Alder (DA) adducts. Thus, the "one-pot" structure-controlled synthesis of HBPs with various degrees of branching was achieved. By further implementation of a programmable temperature change, some valuable hyperbranched topologies such as star-shaped and long-chain hyperbranched polymers can be constructed avoiding sophisticated synthetic routes.

Synthesis and characterization of novel sulfonamide functionalized maleimide polymers: Conventional kinetic analysis, antimicrobial activity and dielectric properties

In this study, novel maleimide monomers, N-sulfamethoxazole maleimide(SMM), and N-sulfanilamide maleimide(SAM) were synthesized. Homopolymers of SMM and SAM were obtained by free radical polymerization method in 1,4-dioxane solvent at 65 °C. The structural characterizations of monomers and their homopolymers were carried out via FTIR, 1H- and 13C-NMR techniques. The glass transition temperature (Tg) of the polymers was determined using differential scanning calorimetry (DSC). Using the thermogravimetric analysis (TGA) method determined the thermal stability of the polymers. The thermal degradation activation energies (Ea) of the polymers were calculated by Kissinger, Flynn Wall Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods. The biological activities of compounds have been also studied on various bacteria and fungi. The weight average (Mw) and number average (Mn) molecular weights of the polymers were determined by gel permeation chromatography (GPC). Photochemical properties of polymers were investigated with ultraviolet (UV) and fourier transform infrared (FTIR) spectra. In addition, some physical constants of polymers such as density, solubility parameter, and viscosity were determined. Finally, the dielectric constant, dielectric loss factor and ac conductivity values ​​of the polymers were estimated in the frequency range of 100 Hz–20 kHz.

Photomediated RAFT step-growth polymerization with maleimide monomers

Photomediated RAFT step-growth polymerization was performed with and without the presence of a photocatalyst using a trithiocarbonate-based CTA and a maleimide monomer.

Investigation of the Side Chain Effect on Gas and Water Vapor Transport Properties of Anthracene-Maleimide Based Polymers of Intrinsic Microporosity.

In the present work, a set of anthracene maleimide monomers with different aliphatic side groups obtained by Diels Alder reactions were used as precursors for a series of polymers of intrinsic microporosity (PIM) based homo- and copolymers that were successfully synthesized and characterized. Polymers with different sizes and shapes of aliphatic side groups were characterized by size-exclusion chromatography (SEC), (nuclear magnetic resonance) 1H-NMR, thermogravimetric (TG) analysis coupled with Fourier-Transform-Infrared (FTIR) spectroscopy (TG-FTIR) and density measurements. The TG-FTIR measurement of the monomer-containing methyl side group revealed that the maleimide group decomposes prior to the anthracene backbone. Thermal treatment of homopolymer methyl-100 thick film was conducted to establish retro-Diels Alder rearrangement of the homopolymer. Gas and water vapor transport properties of homopolymers and copolymers were investigated by time-lag measurements. Homopolymers with bulky side groups (i-propyl-100 and t-butyl-100) experienced a strong impact of these side groups in fractional free volume (FFV) and penetrant permeability, compared to the homopolymers with linear alkyl side chains. The effect of anthracene maleimide derivatives with a variety of aliphatic side groups on water vapor transport is discussed. The maleimide moiety increased the water affinity of the homopolymers. Phenyl-100 exhibited a high water solubility, which is related to a higher amount of aromatic rings in the polymer. Copolymers (methyl-50 and t-butyl-50) showed higher CO2 and CH4 permeability compared to PIM-1. In summary, the introduction of bulky substituents increased free volume and permeability whilst the maleimide moiety enhanced the water vapor affinity of the polymers.

Thermal degradation kinetics and thermodynamics of maleimide-sytrene based alternating copolymer: A comparative investigation of monomer and polymer structures

Thermal degradation of N-(4-(3-Thienyl methylene)-oxycarbonylphenyl) maleimide monomer, MT and its copolymer with styrene, P(MT-alt-St) were investigated comparatively using TG and DTA methods. Degradation of monomer takes place in three stages which correspond to removal of thiophene, aliphatic groups and the rest of structural decomposition respectively. Degradation of the copolymer occurs in two stages. Thiophene and aliphatic groups decompose simultaneously at the first degradation stage. The main polymeric chain remains intact. The second stage is related to the rest of structural decomposition. Activation energy values of these reactions were calculated by using Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods. In order to determine the effective reaction model and calculate thermodynamic parameters, these methods were combined with modeling equations. It was found that the first degradation stages of monomer and copolymer show good harmony with diffusion model (D1), whereas nucleation and growth model (A2) is effective for the second decomposition stage of the monomer.

Synthesis, curing kinetics and thermal properties of two novel quinoxaline-based mono- and bismaleimides

Two novel quinoxaline-based maleimide monomers, 2,3-diphenyl-6-maleimido-quinoxaline (MQMI) and 2,3-di(2-maleimido)phenyl-quinoxaline (BQMI), were successfully synthesized and characterized. Their structure was confirmed by 1H nuclear magnetic resonance (1HNMR) and Fourier transforms infrared (FTIR). The curing behavior was investigated by the rheological method and Differential scanning calorimetry (DSC). Starink method was used for the curing kinetics analysis of MQMI and BQMI monomers. The curing temperature and the apparent activation energy of BQMI were lower than that of MQMI, which indicated that the maleimide group location could affect its curing behavior. The thermal stabilities of the cured quinoxaline-based maleimide resins were detected by Thermogravimetric analysis (TGA), which implied that their decomposition temperatures were comparable with Poly(4,4’-bismaleimido diphenylmethane) (PBMDPM). However, the char yields (Yc) of PMQMI and PBQMI reached 54.1% and 57.3%, respectively, which were much higher than recorded values of PBMDPM.

Design of a maleimide monomer to achieve precise sequence control and functionalization for an alternating copolymer with vinylphenol

We designed an N-phenylmaleimide derivative bearing an activated NHS ester (NHS-PhMI) for radical copolymerization with tert-butoxystyrene (tBOS) to achieve both precise alternating sequence control and functionalization. Essential to the monomer design is the electron-deficient carbon-carbon double bond for precise alternating propagation as well as the facile substitution reaction for the activated ester pendant. The precision of alternating sequences was evaluated by MALDI-TOF-MS analysis in comparison with a series of copolymers. Some amine compounds were quantitatively incorporated onto the maleimide side chain through the aminolysis reaction, whereas the tBOS units were transformed into vinylphenol counterparts via deprotection under acidic conditions. The resultant vinylphenol-based alternating copolymers showed unique solubilities and thermal properties depending on the substituent of the maleimide units. Design of an N-phenyl maleimide derivative bearing an activated NHS ester for radical copolymerization with tert-butoxystyrene to achieve both precise alternating sequence control and functionalization.

Applicability of smart heat resistive polymeric material by non-isothermal thermogravimetric analysis

Homopolymer (H-Mpmi) of 3 -chloro- substituted of N-phenyl maleimide (N-Mpmi) monomer, was synthesized at 60°C in THF using benzoyl peroxide (BPO) as a free radical initiator. The average molecular weight is determined by gel permeation chromatography (GPC). Thermal analysis reveals polymer show single step degradation. The TGA and DTA curves explain its percentage weight loss with temperature at different heating rate 5°C, 10 oC and 15 oC. The non-isothermal kinetic parameters values are obtained using Kissinger method. The activation energy (ΔE*), entropy of activation (ΔS*), enthalpy of activation (ΔH*) and Gibbs free energy (ΔG) increases gradually less with increase in heating rate. Since, endothermic peak was observed in the DTA of homopolymer of meta 3- chloro- substituted of N-phenyl maleimides, H-Mpmi suggesting large amount or bulk mass loss from polymeric chain

Control of Gelation and Properties of Reversible Diels-Alder Networks: Design of a Self-Healing Network.

Reversible Diels–Alder (DA) type networks were prepared from furan and maleimide monomers of different structure and functionality. The factors controlling the dynamic network formation and their properties were discussed. Evolution of structure during both dynamic nonequilibrium and isothermal equilibrium network formation/breaking was followed by monitoring the modulus and conversion of the monomer. The gelation, postgel growth, and properties of the thermoreversible networks from tetrafunctional furan (F4) and different bismaleimides (M2) were controlled by the structure of the maleimide monomer. The substitution of maleimides with alkyl (hexamethylene bismaleimide), aromatic (diphenyl bismaleimide), and polyether substituents affects differently the kinetics and thermodynamics of the thermoreversible DA reaction, and thereby the formation of dynamic networks. The gel-point temperature was tuned in the range Tgel = 97–122 °C in the networks of the same functionality (F4-M2) with different maleimide structure. Theory of branching processes was used to predict the structure development during formation of the dynamic networks and the reasonable agreement with the experiment was achieved. The experimentally inaccessible information on the sol fraction in the reversible network was received by applying the theory. Based on the acquired results, the proper structure of a self-healing network was designed.

Aromatic Nitrogen Mustard-Based Autofluorescent Amphiphilic Brush Copolymer as pH-Responsive Drug Delivery Vehicle.

Delivery of clinically approved nonfluorescent drugs is facing challenges because it is difficult to monitor the intracellular drug delivery without incorporating any integrated fluorescence moiety into the drug carrier. The present investigation reports the synthesis of a pH-responsive autofluorescent polymeric nanoscaffold for the administration of nonfluorescent aromatic nitrogen mustard chlorambucil (CBL) drug into the cancer cells. Copolymerization of poly(ethylene glycol) (PEG) appended styrene and CBL conjugated N-substituted maleimide monomers enables the formation of well-defined luminescent alternating copolymer. These amphiphilic brush copolymers self-organized in aqueous medium into 25-68 nm nanoparticles, where the CBL drug is enclosed into the core of the self-assembled nanoparticles. In vitro studies revealed ∼70% drug was retained under physiological conditions at pH 7.4 and 37 °C. At endolysosomal pH 5.0, 90% of the CBL was released by the pH-induced cleavage of the aliphatic ester linkages connecting CBL to the maleimide unit. Although the nascent nanoparticle (without drug conjugation) is nontoxic, the drug conjugated nanoparticle showed higher toxicity and superior cell killing capability in cervical cancer (HeLa) cells rather than in normal cells. Interestingly, the copolymer without any conventional chromophore exhibited photoluminescence under UV light irradiation due to the presence of "through-space" π-π interaction between the C═O group of maleimide unit and the adjacent benzene ring of the styrenic monomer. This property helped us intracellular tracking of CBL conjugated autofluorescent nanocarriers through fluorescence microscope imaging. Finally, the 4-(4-nitrobenzyl)pyridine (NBP) colorimetric assay was executed to examine the ability of CBL-based polymeric nanomaterials toward alkylation of DNA.

Alternating Placement of d‐ and l‐Alanine Moieties in the Polymer Side‐Chains

AbstractSynthesis of a sequence‐controlled polymer via reversible addition‐fragmentation chain transfer polymerization is reported herein, using an N‐substituted maleimide monomer bearing tert‐butyl carbamate (Boc)‐protected l‐alanine (M1) and Boc‐d‐alanine appended styrenic monomer (M2). The monomer sequence distribution along the polymer chain is thoroughly studied by 1H and 13C NMR spectroscopy and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, confirming the alternating placement of l‐alanine and d‐alanine throughout the polymer chain. Copolymers display fluorescence properties in various organic solvents. After the deprotection of Boc‐groups, the copolymers show fluorescence activity in water (and also in several organic solvents), and pH‐responsiveness in aqueous medium due to the protonation/deprotonation of the side‐chain ‐NH2 groups at varying aqueous solution pH. In addition, the presence of different enantiomeric structures of alanine in the side‐chain enables us to investigate the chiroptical properties of the polymers.

Design of maleimide monomer for higher level of alternating sequence in radical copolymerization with styrene

ABSTRACTThis work deals with design of maleimide monomer toward more precise control of alternating sequence for radical copolymerization with styrene. Crucial in this study is sequence analysis by MALDI‐TOF‐MS for resultant copolymers that was obtained via ruthenium‐catalyzed living radical copolymerization with a malonate‐based alkyl halide initiator showing selective initiation ability. The copolymers of a simple N‐alkyl maleimide [e.g., N‐ethyl maleimide (EMI)] with styrene gave complicated peak patterns for the MALDI‐TOF‐MS spectra indicating low degree of alternating sequence, in contrary to expectation from the reactivity ratios (almost zero). A simple substitution of methyl group (CH3) of EMI with trifluoromethyl (CF3: CF3‐MI) made the peak patterns much simpler giving the copolymer with higher alternating sequence. More interestingly, the peak interval of the copolymer at earlier polymerization stage was equal to sum of the molecular weights of CF3‐MI and styrene, suggesting possibility of the pair propagation of the monomers. Indeed, 1H NMR analyses of the mixture of maleimide with styrene suggested stronger interaction of CF3‐MI than EMI. Based on the results, maleimide derivatives carrying a substituent‐designable electron‐withdrawing group [ROC(O)N–: R = substituent] were newly designed toward incorporation of functional side chains. They also gave higher alternating sequence for the copolymerization with styrene. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 367–375

ANTIMICROBIAL EVALUATION OF MALEIMIDE MONOMERS, HOMOPOLYMERS AND COPOLYMERS CONTAINING AZO, SULPHONAMIDE AND THIAZOLE GROUPS

New maleimide Monomers, homopolymers and copolymers containing azo, sulfonamide and thiazole groups were synthesized. The structures of newly synthesized compounds have been characterized on the basis of their spectroscopic data (FT-IR and 1H-NMR). Antimicrobial studies of synthesized compounds were performed using agar well diffusion method. All the compounds showed pronounced activity against bacterial strains in comparison to activity against fungal strains.The highest antibacterial potency was exhibited by the homopolymer HPSPMI against Escherichia coli, Klebsiella pneumoniae and Bacillus subtilis. The activity of HPSPMI against later two was more pronounced than the standard drug used. Only Selected compounds showed antifungal activity. Appreciable results were found against Aspergillus fumigates but not with Candida albicans. HPSPMI showed highest activity against Aspergillus fumigates. Surprisingly after homo and copolymerization, maximum compounds exhibited not only pronounced antibacterial activity but also antifungal activity.

High-Temperature Resistive Free Radically Synthesized Chloro-Substituted Phenyl Maleimide Antimicrobial Polymers

ABSTRACTHomopolymerization of chloro-substituted N-phenyl maleimide monomer at ortho N-OCPMI, meta N-MCPMI, and para N-PCPMI was performed at 70°C in DMF using benzoyl peroxide as a free radical initiator. The average molecular weight of all homopolymers, namely, H-OCPMI H-MCPMI and H-PCPMI by gel permeation chromatography was found to be 1,806, 2,464, and 4,542 with PDI 1.07, 1.09, and 1.11. The controlled poly dispersity index by conventional free radical polymerization is achieved. The thermal analyses reveal that the initial decomposition temperatures for all types of homopolymers are close to each other. On increasing heating rates, the activation energy (ΔE*),entropy of activation (ΔS*), enthalpy of activation (ΔH*), and Gibbs free energy (ΔG) increase for all types of homopolymers. The homopolymer of para chloro-substituted of N-phenyl maleimide, H-PCPMI has the highest thermal stability. All the synthesized monomers and homopolymers are found to show an excellent antimicrobial activity. Activity index is also evaluated.

Fabrication of Thiol-Ene "Clickable" Copolymer-Brush Nanostructures on Polymeric Substrates via Extreme Ultraviolet Interference Lithography.

We demonstrate a new approach to grafting thiol-reactive nanopatterned copolymer-brush structures on polymeric substrates by means of extreme ultraviolet (EUV) interference lithography. The copolymer brushes were designed to contain maleimide functional groups as thiol-reactive centers. Fluoropolymer films were exposed to EUV radiation at the X-ray interference lithography beamline (XIL-II) at the Swiss Light Source, in order to create radical patterns on their surfaces. The radicals served as initiators for the copolymerization of thiol-ene "clickable" brushes, composed of a furan-protected maleimide monomer (FuMaMA) and different methacrylates, namely, methyl methacrylate (MMA), ethylene glycol methyl ether methacrylate (EGMA), or poly(ethylene glycol) methyl ether methacrylate (PEGMA). Copolymerization with ethylene-glycol-containing monomers provides antibiofouling properties to these surfaces. The number of reactive centers on the grafted brush structures can be tailored by varying the monomer ratios in the feed. Grafted copolymers were characterized by using attenuated total reflection infrared (ATR-IR) spectroscopy. The reactive maleimide methacrylate (MaMA) units were utilized to conjugate thiol-containing moieties using the nucleophilic Michael-addition reaction, which proceeds at room temperature without the need for any metal-based catalyst. Using this approach, a variety of functionalities was introduced to yield polyelectrolytes, as well as fluorescent and light-responsive polymer-brush structures. Functionalization of the brush structures was demonstrated via ATR-IR and UV-vis spectroscopy and fluorescence microscopy, and was also indicated by a color switch. Furthermore, grafted surfaces were generated via plasma activation, showing a strongly increased wettability for polyelectrolytes and a reversible switch in static water contact angle (CA) of up to 18° for P(EGMA-co-MaMA-SP) brushes, upon exposure to alternating visible and UV-light irradiation.

Indispensable platforms for bioimmobilization: maleimide-based thiol reactive hydrogels.

Poly(ethylene glycol)-based hydrogels containing thiol-reactive maleimide functional groups is prepared via a Diels-Alder/retro Diels-Alder reaction sequence using a masked maleimide monomer. Bulk and micropatterned hydrogels containing varying amounts of the thiol-reactive maleimide functional group are fabricated at ambient temperature. During the fabrication, the reactive maleimide functional group in the monomer is masked with a furan moiety and then unmasked to its reactive form via the retro-Diels-Alder reaction. The reactive maleimide groups embedded within the hydrogel are amenable to facile and efficient functionalization with thiol-containing molecules such as fluorescent dyes. Furthermore, these hydrogels are readily biotinylated using the nucleophilic thiol-ene conjugation to enable immobilization of streptavidin onto the hydrogel patterns to achieve facile bioimmobilization. Notably, the extent of functionalization of these hydrogels can be easily tailored by varying the amount of reactive handles incorporated during their fabrication.

Electron beam curing of functionalized N-(4-hydroxy phenyl)maleimide monomers

Electron beam (E-beam) curing by different total radiation doses (100, 200, 300 and 400 kGy at 10 kGy per pass) of functionalized maleimides (20%) [ N-(4-acryloyloxy phenyl)maleimide, N-(4-methacryloyloxy phenyl)maleimide and N-(4-cyanato phenyl)maleimide] is carried out using N-vinyl-2-pyrrolidone as the reactive diluent (80%). The swelling studies indicate the presence of highly cross-linked structure in the polymer derived from cyanate-functionalized maleimide cured using 400 kGy electron beam (E-beam) irradiation. The thermal stabilities of all the polymers are studied using thermogravimetric analyzer. The materials cured using the highest radiation dose (400 kGy) are found to have better thermal stability compared to other materials cured using lower doses (100, 200 and 300 kGy at 10 kGy per pass). The degradation kinetic studies using the Vyazovkin method showed that the activation energies for the thermal degradation of polymeric materials got by E-beam irradiation of the monomers at 400 kGy are higher. Of all the materials investigated, liquid composition having N-(4-cyanato phenyl)maleimide (20%) and N-vinyl-2-pyrrolidone (80%) cured by E-beam radiation (400 kGy) showed better thermal stability.