Dicyanate Ester Research Articles

Linear polyborosiloxane for improving the flame-retardancy of cyanate ester resin

The increasing demands for electronic packing materials necessitate stringent criteria for the overall properties of cyanate ester (CE) resins. In this work, a novel linear polyborosiloxane with a distinctive organic-inorganic hybrid Si–O–B backbone, featuring functional epoxy and phenyl groups (denoted as LPSi-B), was synthesized via a solvent- and catalyst-free one-pot polycondensation. Subsequently, the synthesized LPSi-B was co-crosslinked within the bisphenol A dicyanate ester (BADCy) thermoset network. The presence of abundant active epoxy groups in LPSi-B facilitated its involvement in the cyanate curing reaction, demonstrating excellent compatibility within the resin matrix. The resulting LPSi-B/BADCy composite not only exhibits outstanding mechanical properties but also demonstrates notable flame-retardant and dielectric characteristics. Specifically, the hybrid nature of LPSi-B, combining the flexibility of Si–O–B chains with the rigidity of side-chain phenyl groups, fosters intermolecular non-covalent π-π interactions directly linked to boron atoms, thus mitigating network polarization. Furthermore, the synergistic flame-retardant effect arising from boron and silicon components was harnessed to achieve halogen-free, phosphorus-free, and environmentally friendly fire safety outcomes. This innovative design ensures exceptional compatibility and interface bonding between LPSi-B and the polymer matrix, thereby endowing cyanate ester resin with superior comprehensive performance suitable for advanced applications in wave-transparent and electronic packing materials.

Catalytic effect of N-phenylaminopropyl polyheadral oligomeric silsesquioxane in the synthesis of hybrid nanocomposites based on polycyanurate

Organic-inorganic nanocomposites based on heat-resistant crosslinked polycyanurate (PCN) and N-phenylaminopropyl polyhedral oligomeric silsesquioxane (NPAP-POSS), containing eight reactive secondary amino groups, were synthesized using the in situ reactive formation method. Fourier transmission infrared (FTIR) spectroscopy and dynamic differential scanning calorimetry (DSC) methods were used to study the effect of NPAP-POSS on the kinetics of bisphenol E dicyanate ester (DCBE) polycyclotrimerization during the formation of PCN in PCN/NPAP-POSS nanocomposites. The content of the nanofiller was varied from 0.05 to 1.00 wt.%. Based on the results of FTIR spectral studies, the main kinetic peculiarities of PCN formation were found and their changes under the action of NPAP-POSS nanofiller were determined. A significant catalytic effect of NPAP-POSS on the polycyclotrimerization of DCBE was found, which is confirmed by a decrease in the time of the onset of auto-acceleration, an acceleration of the conversion of cyanate groups of DCBE and the formation of triazine cycles of PCN, an increase in the values of the maximum reaction rate, a decrease in the duration of the reaction, etc. The dynamic DSC method also confirmed the catalytic effect of NPAP-POSS on the formation of PCN in the nanocomposites and established the main kinetic characteristics depending on the content of the nanofiller: a significant decrease in the temperature of the exothermic maximum, an increase in the reaction enthalpy, non-monotonic changes in the induction period and reaction rate, etc. From the analysis of the experimental data, it was concluded that the detected changes in the kinetics of the in situ reaction formation of PCN/NPAP-POSS nanocomposites and the recorded catalytic effect of the nanofiller are due to the fact that two chemical processes occur during the synthesis of the nanocomposites: chemical interaction of –O–C≡N groups of DCBE with secondary –NH groups of NPAP-POSS, which led to further embedding of nanoparticles into the resulting polymer matrix and the direct polycyclotrimerization of DCBE with formation of hybrid polycyanurate network. Schemes of the sequential reactions explaining the catalytic effect of the nanofiller in the synthesis of hybrid PCN/NPAP-POSS nanocomposites are proposed. It was concluded that under the selected conditions of the synthesis, the greatest catalytic effect of the nanofiller is manifested at its content of 0.10 wt.%, since for this sample the maximum shift of the reaction exothermic peak towards lower temperatures, the maximum reaction rate, and the minimum induction period and reaction start temperature were recorded. The results of the research make it possible to optimize the synthesis of heat-resistant materials promising for use in special-purpose structures.

Development of a multistep-GRRM/MC/MD simulation method for the formation of crosslinked network structures via multistep reversible reaction pathways

Molecular dynamics (MD) simulations offer insights into high-performance polymer attributes and assist in creating novel materials. However, simulating cyanate resin systems remains a challenge due to the complexities of triazine ring formation. While earlier research efforts have been made, a consistent procedure for analyzing cyanate resins remains elusive. This research introduces a precise and replicable method for modeling cyanate resin systems, focusing on triazine ring formation processes. The technique combines a crosslinking method, a unique ring-formation algorithm, and a protocol for MD simulations. Using Bisphenol A dicyanate ester (BPACN) as the monomer, a polymer model is created. Predicted attributes like a glass transition temperature of 298.7 ± 3.7 °C and a Young's modulus of 2.95 ± 0.22 GPa align well with experimental data. This innovative method offers a blueprint for other triazine ring formations.

Regulation and prediction of the dielectric constant and interfacial binding energy of surface modified hexagonal boron nitride/polyphenylene oxide@cyanate ester resin

AbstractParticulate‐filled materials with superior mechanical properties and wave permeability have received extensive research attention in the military industry. To elucidate the role of reinforcement in polymers, γ‐Aminopropyltriethoxysilane (APTES) is used to modify hexagonal boron nitride (h‐BN) nanoparticles, which are then filled into polyphenylene oxide@bisphenol A dicyanate ester composite, exhibiting a 1.46‐fold increase in flexural strength and a dielectric constant of 2.66 at 12 GHz. Finite element analysis is employed to design composite material models, successfully predicting the dielectric properties of composites at different frequencies and reinforcement filling levels. The change in the interface energy induced by the silane coupling agent is quantitatively calculated by molecular dynamics simulation, demonstrating that the modified nanoparticles are conducive to improving the flexural strength. Overall, the predicted dielectric and mechanical properties of composites can be utilized to screen for composites that possess excellent dielectric and mechanical properties, thereby greatly improving efficiency.Highlights A hexagonal boron nitride/polyphenylene oxide@cyanate ester is prepared. Finite element analysis is employed to predict the dielectric properties. The interface energy is calculated by molecular dynamics simulation. The resin has superior mechanical and dielectric properties.

Block copolymer functionalized quartz fibers/cyanate ester wave-transparent laminated composites

A block copolymer of PDMS- b -PGMA is synthesized by polymerizing glycidyl methacrylate (GMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization applying a polydimethylsiloxane (PDMS) based macro-RAFT agent, which is then performed to functionalize the quartz fibers (QFs@PDMS- b -PGMA) via a simple coating process. Finally, the QFs@PDMS- b -PGMA/bisphenol A dicyanate ester (BADCy) wave-transparent laminated composites are fabricated by high-temperature molding. Nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and size exclusion chromatography (SEC) demonstrate the successful preparation of PDMS- b -PGMA with expected structure. When the molar mass and coating amount of PDMS- b -PGMA are respectively 8100 g/mol and 2.0 wt.%, QFs@PDMS- b -PGMA/BADCy wave-transparent laminated composites present optimal mechanical properties and wave-transparent performance. The interlaminar shear strength (ILSS) and flexural strength are 53.6 and 552.0 MPa, respectively. Meanwhile, the dielectric constant and dielectric loss values are 2.61 and 0.0028 at 1 MHz (wave transmittance of 93.8%), showing good stability at different frequencies (10 2 -10 6 Hz and 8.4-12.4 GHz) and temperatures (25-250 °C).

Branched Fluorine/Adamantane Interfacial Compatibilizer for PBO Fibers/Cyanate Ester Wave‐Transparent Laminated Composites

Comprehensive SummaryBranched fluorine/adamantane PBO precursor (preFABPBO), synthesized via random co‐condensation between 2,2‐bis(3‐amino‐ 4‐hydroxyphenyl)hexafluoro propane, 1,3‐adamantanedicarbonyl dichloride, and trimesoyl chloride, is performed as interfacial compatibilizer, bisphenol A dicyanate ester (BADCy) resin as polymer matrix, and poly(p‐phenylene‐2,6‐benzobisoxazole) (PBO) fibers as reinforcements to prepare PBO fibers/FABPBO‐BADCy wave‐transparent laminated composites by high temperature molding. The mechanical properties, wave‐transparent performances, and heat resistances of PBO fibers/BADCy composites are simultaneously improved by the addition of preFABPBO. The interlaminar shear strength (ILSS) and flexural strength of PBO fibers/FABPBO‐BADCy composites are 48.9 and 665.3 MPa, respectively, increased by 33.2% and 13.3% compared to those of PBO fibers/BADCy composites (36.7 and 587.4 MPa). The dielectric constant and dielectric loss values at 106 Hz are 2.53 and 0.003, respectively, lower than those of PBO fibers/BADCy composites (3.06 and 0.006), and the corresponding wave transmission efficiency is 94.8%, which also presents excellent stability over the wide temperature (25—200 °C) and frequency range (103—107 Hz and 8.2—12.4 GHz). Meanwhile, the heat resistance index and glass transition temperature are 229.9 °C and 247.5 °C, also better than those of PBO fibers/BADCy composites (229.6 °C and 247.1 °C).

PBO fibers/fluorine-containing liquid crystal compound modified cyanate ester wave-transparent laminated composites with excellent mechanical and flame retardance properties

Bisphenol A dicyanate ester resins modified by fluorine-containing liquid crystal compound (LCFE) are applied as polymer matrix (LCFE-BADCy), poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers as reinforcements, and fluorine/adamantane PBO precursor (preFABPBO) as interfacial compatibilizer to prepare the corresponding PBO fibers/FABPBO/LCFE-BADCy wave-transparent laminated composites. LCFE could improve the order degree of BADCy cured network, in favor of enhancing the wave-transparent performance, mechanical properties, and intrinsic thermal conductivity. The dielectric constant and dielectric loss of PBO fibers/FABPBO/LCFE-BADCy composites are highly temperature (25–200 °C) and frequency (104–107 Hz and 8.2–12.4 GHz) stable with the value of 2.49 and 0.003 under 106 Hz at 25 °C, and the corresponding wave transmission efficiency is 95.0%, higher than that of 92.5% for PBO fibers/BADCy composites. The interlamellar shear strength and flexural strength are respectively 50.7 MPa and 682.5 MPa, 38.1% and 16.2% higher than those of PBO fibers/BADCy composites. Besides, the volume resistivity, breakdown voltage, heat resistance index, glass transition temperature, flame retardant grade, and ultimate oxygen index of PBO fibers/FABPBO/LCFE-BADCy composites are respectively 5.3 × 1015 Ω cm, 29.75 kV/mm, 217.2 °C, 245.7 °C, V-1 grade, and 33.6%, expected to be performed as a new generation of “lightweight/loading/wave-transparent” electromagnetic window materials in advanced military weapons and civil communication base station.

High Thermal Resistance of Epoxy/Cyanate Ester Hybrids Incorporating an Inorganic Double-Decker-Shaped Polyhedral Silsesquioxane Nanomaterial.

In this study, we prepared a difunctionalized cyanate ester double-decker silsesquioxane (DDSQ-OCN) cage with a char yield and thermal decomposition temperature (Td) which were both much higher than those of a typical bisphenol A dicyanate ester (BADCy, without the DDSQ cage) after thermal polymerization. Here, the inorganic DDSQ nanomaterial improved the thermal behavior through a nano-reinforcement effect. Blending the inorganic DDSQ-OCN cage into the epoxy resin improved its thermal and mechanical stabilities after the ring-opening polymerization of the epoxy units during thermal polymerization. The enhancement in the physical properties arose from the copolymerization of the epoxy and OCN units to form the organic/inorganic covalently bonded network structure, as well as the hydrogen bonding of the OH groups of the epoxy with the SiOSi moieties of the DDSQ units. For example, the epoxy/DDSQ-OCN = 1/1 hybrid, prepared without Cu(II)-acac as a catalyst, exhibited a glass transition temperature, thermal decomposition temperature (Td), and char yield (166 °C, 427 °C, and 51.0 wt%, respectively) that were significantly higher than those obtained when applying typical organic curing agents in the epoxy resin. The addition of Cu(II)-acac into the epoxy/BADCy and epoxy/DDSQ-OCN hybrids decreased the thermal stability (as characterized by the values of Td and the char yields) because the crosslinking density and post-hardening also decreased during thermal polymerization; nevertheless, it accelerated the thermal polymerization to a lower curing peak temperature, which is potentially useful for real applications as epoxy molding compounds.

Design and Evaluation of a Cyanate Ester Containing Oxaspirocyclic Structure for Electronic Packaging

A type of pentaerythritol cinnamaldehyde bisphenol dicyanate ester (PCBDCy) containing oxaspirocyclic structure is well designed and synthesized in three steps from cinnamaldehyde, pentaerythritol, phenol, and cyanogen bromide. The products in each step are characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, and 1H NMR spectroscopy. The mechanical properties, dielectric properties, thermostability, and water absorption of PCBDCy are investigated in detail. The results show that compared with bisphenol A dicyanate (BADCy), the PCBDCy possesses more excellent comprehensive properties. The bending strength and flexural strength are increased by 10.71% and 47.62%, respectively. The fracture toughness K IC and G IC are 1.5 times and 2 times of BADCy, respectively, indicating that its mechanical properties have been considerably improved. The dynamic mechanical curves indicates that the degree of phase separation is significantly reduced, the tan (δ) value representing the flexible phase is obviously shifted to the high temperature region, and the initial decomposition temperature was 12°C higher than that of BADCy, indicating that the material has excellent thermal stability. In addition, the dielectric constant and loss tangent are almost as same as those of BADCy, maintaining good dielectric properties. The water absorption rate has increased to 1.03 ± 0.03 % . Compared with BADCy, its comprehensive performance is more suitable for the field of microelectronic packaging.

The Created Excellent Thermal, Mechanical and Fluorescent Properties by Doping Eu3+-Complex-Anchored Carbon Nanotubes in Polycyanate Resins.

In the blending process of the composites, the clustering of MWCNTs under high concentration leads to poor dispersion and difficult complexing with luminescent elements. Cyanate ester resins (CERs) have a brittle network structure when cured caused by a conjugation effect that forms a strong emission peak in the ultraviolet-visible region and quenches the luminescent elements of the fluorescent nanofillers. In this paper, by anchoring of the Eu complex (Eu(TTA)3Phen, ETP) on a surface of longitudinal split unzipped carbon nanotubes (uMWCNTs); fluorescent nanoparticles were prepared as ETP anchor unzipper carbon nanotubes (ETP-uCNTs). Dicyanate ester of bisphenol E (CER-E monomer) is cured to polycyanurate at a lower temperature to achieve a high conversion, promoting a uniform blend with ETP-uCNTs, providing the fluorescence environment with high color purity. Studies show the ETP-uCNTs solve the agglomeration of MWCNTs and improve the interface binding ability. Compared with the pure CER-E, the tensile strength, bending strength and impact strength of CER-E/0.8 wt.% ETP-uCNT hybrid nanocomposites are increased by 94.6%, 92.8% and 101.1%, respectively. The carbon residue rate of CER-E/ETP-uCNTs is up to 47.14% at 800 °C, the temperature of the maximum reaction rate decreases by 67.81 °C, and the partial absorption of ultraviolet light is realized between 200 and 400 nm.

The Kinetics of Formation of Microporous Polytriazine in Diphenyl Sulfone.

This study highlights the value of nonisothermal kinetic methods in selecting temperature conditions for the isothermal preparation of microporous polymeric materials. A dicyanate ester is synthesized and the kinetics of its polymerization in diphenyl sulfone are studied by calorimetry under nonisothermal conditions. The kinetics are analyzed by a model-based approach, using the Kamal model, as well as by a model-free approach, using an advanced isoconversional method. Both approaches correctly predict the time to completion of polymerization at a given temperature. The material prepared independently at the predicted temperature is characterized by electron microscopy and CO2 adsorption measurements and is confirmed to possess a microporous structure with a multimodal distribution of micropores with two major maxima at ~0.5 and 0.8 nm.

Significantly improved interfacial properties and wave-transparent performance of PBO fibers/cyanate esters laminated composites via introducing a polydopamine/ZIF-8 hybrid membrane

Polydopamine hybrid zeolitic imidazolate framework-8 (PDA*ZIF-8) membrane, synthesized by zinc nitrate hexahydrate (ZnNO3•6H2O), 2-methylimidazole (2-MI), and dopamine (DA), uniformly grows on the surface of poly(p-phenylene-2, 6-benzobisoxazole) (PBO) fibers by heterogeneous nucleation method to obtain PBO@PDA*ZIF-8 fibers. PBO@PDA*ZIF-8 fibers are then applied as the reinforcement, bisphenol A dicyanate ester (BADCy) as the matrix, and PBO@PDA*ZIF-8 fibers/BADCy wave-transparent laminated composites are prepared by high-temperature molding. Results indicate that PDA*ZIF-8 membrane increases the surface roughness and chemical activity of PBO fibers. The interlaminar shear strength (ILSS) and flexural strength of PBO@PDA*ZIF-8 fibers/BADCy laminated composites are 45.3 and 656.3 MPa, respectively, which are increased by 23.4% and 11.7% compared with those of PBO fibers/BADCy composites (587.4 and 36.7 MPa). The dielectric constant and dielectric loss values at 1 MHz are 2.76 and 0.0046, respectively, lower than PBO fibers/BADCy (3.06 and 0.006). At 0.3–40 GHz, PBO@PDA*ZIF-8 fibers/BADCy laminated composites have excellent wave-transparent performance (The simulated wave-transparent rate is greater than 87%, d = 1.5–3.5 mm). Meanwhile, the corresponding volume resistivity and breakdown strength are 3.7 × 1015 Ω•cm and 23.61 kV/mm, higher than PBO fibers/BADCy composites (2.2 × 1015 Ω•cm and 17.69 kV/mm), respectively.

Novel adamantane-based dicyanate ester: Synthesis, polymerization kinetics, and thermal properties of resulting polymer

A new adamantane-based dicyanate ester has been synthesized. The kinetics of its thermal polymerization is studied by means of conventional and temperature-modulated differential scanning calorimetry. The kinetics is analyzed comprehensively by a combination of an advanced isoconversional and model-fitting method. Polymerization proceeds via transition from a kinetic- to diffusion-control regime, which becomes operative at the later stages of the process. The kinetically-controlled regime manifests itself as a quasi-one-step auto-catalytic reaction. A contribution of diffusion to the overall kinetic is accounted for by means of the Fournier model. The polymerization product possesses excellent thermal properties (the glass transition temperature of ∼370 °C and 5% mass loss temperature of ∼480 °C), which makes it a promising candidate for application in hot-section components for aerospace and military industry.

Improving the comprehensive properties of PBO fibres/cyanate ester composites using a hyperbranched fluorine and epoxy containing PBO precursor

Hyperbranched fluorine and epoxy containing PBO precursor (epoxy-preFHBPBO) was synthesized and utilized as interface compatibilizer to synchronously improve the mechanical and dielectric properties of poly(p-phenylene-2, 6-benzobisoxazole) (PBO) fibres reinforced bisphenol A dicyanate ester (BADCy) resins (PBO fibres/FHBPBO-co-BADCy) laminated composites. 1H NMR, 13C NMR, and FTIR analyses confirmed the successful preparation of epoxy-preFHBPBO. The introduction of hyperbranched structure and fluorine groups significantly improved the mechanical properties and wave-transparent performance. Compared with PBO fibres/BADCy, the flexural strength and interlaminar shear strength of PBO fibres/FHBPBO-co-BADCy composites with 7 wt% epoxy-preFHBPBO were respectively enhanced to 634.9 and 46.9 MPa, increased by 8.1% and 27.8%. The corresponding dielectric constant and dielectric loss were 2.65 and 0.003, respectively, lower than those of PBO fibres/BADCy (3.06 and 0.006) composites. Meanwhile, the corresponding volume resistivity and breakdown strength were 4.93 × 1015 Ω•cm and 25.38 kV/mm, higher than PBO fibres/BADCy resins composites (2.2 × 1015 Ω•cm and 17.69 kV/mm).

Polymerization kinetics of adamantane-based dicyanate ester and thermal properties of resulting polymer

The kinetics of liquid-state polymerization of adamantane-based dicyanate ester has been studied for the first time by means of conventional and temperature-modulated DSC. It has been detected that the later stages of polymerization undergo a transition from kinetic- to diffusion-controlled regime. Detailed analysis of the polymerization kinetics in the reaction-controlled regime has revealed that the process rate can be well described in the frameworks of the presently proposed autocatalytic quasi-one-step model. The proposed model eliminates arbitrarily guessing the value for the initial conversion that provides a reasonable alternative to the broadly used truncated Sestak-Berggren model. The adamantane-based dicyanate ester polymerization product demonstrates markedly higher thermal stability and glass transition temperature compared to those of dicyanate esters with flexible hydrocarbon bridging units. The obtained experimental results confirm our hypothesis about the influence of the rigidity of cyanate ester molecule on its reactivity and thermal properties of the corresponding polymer product.

Optimization of PBO fibers/cyanate ester wave-transparent laminated composites via incorporation of a fluoride-containing linear interfacial compatibilizer

Bisphenol A dicyanate ester (BADCy) was utilized as the matrix, poly (p-phenylene-2, 6-benzobisoxazole) (PBO) fibers as the reinforcement, and synthesized fluorine-containing linear PBO precursor (preFLPBO) as the interfacial compatibilizer to prepare PBO fibers/FLPBO-m-BADCy wave-transparent laminated composites. The fluorine groups and PBO-like structures could respectively improve the dielectric properties of BADCy matrix and the interfacial compatibility between the BADCy matrix and PBO fibers. Additionally, the partly interpenetrating network formed between preFLPBO and BADCy could significantly improve the mechanical properties. PBO fibers/FLPBO-m-BADCy wave-transparent laminated composites with 7 wt% preFLPBO displayed the optimal comprehensive performances. Dielectric constant (ε) and dielectric loss (tanδ) were respectively 2.90 and 0.0042, and the corresponding theoretical wave-transmittance (|T|2) at 1 MHz was 93.3%, higher than that of PBO fibers/BADCy wave-transparent laminated composites. The minimum percentage of simulated electromagnetic wave-transparent energy (ET (simulation)) of the PBO fibers/FLPBO-m-BADCy (1 mm) wave-transparent laminated composites at 0.3~40 GHz was 87.3%, also better than PBO fibers/BADCy wave-transparent laminated composites (85.9%). The flexural and interlaminar shear strength (ILSS) of PBO fibers/FLPBO-m-BADCy wave-transparent laminated composites were increased from 587.4 and 36.7 MPa to 628.0 and 44.8 MPa, respectively. In addition, the corresponding volume resistivity and breakdown voltage were 2.7 × 1015 Ω·cm and 19.12 kV/mm, respectively.

Curing behavior and flexural properties of cyanate composites reinforced with rare earth- and silane-modified basalt fibers

Herein, basalt fibers (BFs) modified by treatment with (3-aminopropyl) triethoxysilane and lanthanum ethylenediaminetetraacetic acid were used to fabricate BF-reinforced bisphenol A dicyanate ester composites via cast molding, and the effects of the modification method on the surface chemical groups and structures of BFs were determined using a range of instrumental techniques. Both modifications increased the number of functional groups on the BF surface. Silane treatment was shown to increase the BF surface roughness to a greater extent than rare earth treatment. Subsequently, we investigated the curing behavior and mechanical properties of BF-reinforced composites, demonstrating that the curing temperature of bisphenol A dicyanate ester was more effectively lowered by the incorporation of lanthanum-modified BFs than by that of silane-modified BFs. Additionally, the composite containing 12 wt% La-modified BFs exhibited flexural strength and modulus that exceeded those of the composite containing 12 wt% silane-modified BFs (by 15 MPa and 0.6 GPa, respectively), which was ascribed to the higher strength of La-modified fibers and the higher extent of curing and moderate interfacial adhesion of the former composites. In summary, lanthanum ethylenediaminetetraacetic acid was proven to be a more effective modifier than (3-aminopropyltriethoxy) silane for improving the curing behavior and flexural properties of the composites.

Synthesis and Polymerization Kinetics of Novel Dicyanate Ester Based on Dimer of 4‐tert‐butylphenol

AbstractA novel dicyanate ester, which constitutes the first member of the family of linear oligomers of 4‐tert‐butyl‐phenol, is synthesized as a part of the systematic study on the relation between the reactivity of cyanate esters and their structure. The synthesized monomer undergoes thermally stimulated polymerization in the melt. The kinetics of polymerization is studied by conventional and temperature‐modulated DSC. Detailed isoconversional analysis of the obtained kinetic data has revealed that the process rate is limited by a single reaction step of the auto‐catalytic nature. Thermal stability and glass transition temperature of polymerization product are characterized by means of thermogravimetry and fast scanning calorimetry.

Cyanate ester resins toughened with epoxy-terminated and fluorine-containing polyaryletherketone

A novel epoxy-terminated and fluorine-containing polyaryletherketone modified bisphenol A dicyanate ester resin showed significantly improved comprehensive properties.

Study of functionality of polymer films by dense electron beams

Methodology of using megavolt electrons for investigation of the functionality of thin polymer films of polycyanurates (PCN) is described. The relevance of research is determined by the prospects of using films as a functional basis for improvement of track-etched technologies of nanoporous nuclear filters, where ionizing radiation is used in most of technological stages of their production. Functionality control is the main criterion for the qualification of films on the suitability for production of nuclear filters on their base. Development of megavolt electrons radiation methods is promising for monitoring the functionality of filters. Radiation technologies are universal and able to provide maximum information content on investigations of the characteristics of materials to qualify them for suitability of practical use. To control the functionality of the films, the methodology for research and testing of thin polymer films using powerful electron beams of 1-2 MeV has been developed. The features of these methods and the results of their application at the control of functionality and for the qualification of the films based on crosslinked polycyanurates, synthesized by in situ polycyclotrimerization of dicyanate ester of bisphenol E in the presence of dimethylphthalate (DMPh) of the composition PCN/DMPh=70/30 wt.%, on the suitability for production of nanoporous track membranes are discussed. Key words: electron beams, nuclear membranes, thermostable polycyanurates, radiation stability, functional testing.