Cyanate Resin Research Articles

High heat resistance and neutron shielding performance epoxy with carborane hybridized crosslinked network

Epoxy resin has gained significant attention in aviation equipment, coatings and electronic packaging materials due to its exceptional processability, adhesion and mechanical properties. However, its thermal resistance property and glass transition temperature (Tg) were relatively lower than cyanate resin (CE), polyimides (PI) and phenolic resins (PF), which largely restricts its application range. In this work, we had developed a new structural heat-and-shielding integrated epoxy resin via the design of carboranes-epoxy network. Benefiting from the structure of carborane, the thermal residual weight of the obtained epoxy reached 64.57 %, with a carbon atom protection rate of 45.47 % in air atmosphere at 800 °C, showing better thermal resistance property than most CE, PI and PF. And the Tg of the new epoxy was not observed within the tested temperature range (50–250 °C). Additionally, the introduction of carborane structures enhances the neutron shielding performance of the material (38.46 % enhanced). The reinforcement mechanisms of these above properties are systematically investigated. It's excepted that our work could provide some ideas to prepare structural -functional integrated epoxy and promote the development of carborane related materials.

Catalytic cyanate resin with polysulfide cation catalyst and its ultra‐high molecular weight polyethylene fiber composites for radome

AbstractCyanate (CE) resin and ultrahigh‐molecular‐weight polyethylene (UHMWPE) fiber are respectively important matrix and reinforcing material for lightweight and high wave‐transparent composites. However, the preparation and application of the composites is limited by the mismatch of molding temperature between CE resin and UHMWPE fiber. The best method to solve this problem is to catalyze the CE resin curing reaction and reduce its molding temperature from 270 to 135°C, which is the upper heat‐resistance temperature of UHMWPE fiber. In this study, the polysulfide catalyst (PSC) was used to catalyze CE resin curing reaction, reduce the curing reaction activation energy and the molding temperature. The apparent activation energy of the CE‐PSC resin decreases from 107.2 to 60.7 kJ mol−1, and the glass transition temperature of the CE‐PSC resin is 257.2°C, flexural strength and tensile strength are 120.2 and 60.8 MPa, respectively. As a result, the CE‐PSC/UHMWPE fiber composites, which are molded at the matching temperature of 135°C, have low density of 1.05 g cm−3, low dielectric constant of 2.4, low dielectric loss of 0.006, and high wave transmittance of 92.2%. Therefore, the CE‐PSC/UHMWPE fiber composites have wide application prospect in the field of light weight and high wave‐transparent composites.Highlights A novel catalytic CE resin can be cured at 135°C with low dielectric properties. The processing temperature mismatch between CE and UHMWPE fiber was solved. Catalytic CE/UHMWPE composites have lightweight and high wave‐transparent properties.

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.

Investigation on mechanical properties and thermal expansibility of epoxy resin copolymerization modified cyanate ester under medium‐low temperature curing process

AbstractIn this paper, the mechanical properties and thermal expansibility of cyanate resin (CE) copolymerization modified by epoxy resin (EP) under medium‐low temperature curing process were studied. The curing temperature of the modified resin was analyzed, and the results showed that the initial curing temperature of the copolymerization resin was reduced by 87°C compared with the blend resin and further reduced when dibutyltin‐dilaurate was used. The results of mechanical properties test showed that the tensile and bending strength of the modified resin were the highest, which were 55.5 and 97.3 MPa, respectively. The results of scanning electron microscopy showed that the modified resin with 80 wt% cyanate content had the coarsest tensile and bending sections, the largest number of fracture stripes and rich layers, so it had relatively better toughness. The linear thermal expansion coefficient (CTE) of modified resin was determined and the results showed that when the loading of cyanate was 80 wt%, the CTE of the modified resin reached the lowest, only 6.36 × 10−5°C−1.

Self-Compositing: A Efficient Method of Improving the Electrical Conductivity of Graphene Nanoplatelet/Thermosetting Resin Composites.

Conductive composites based on thermosetting resins have broad applications in various fields. In this paper, a new self-compositing strategy is developed for improving the conductivity of graphene nanoplatelet/thermosetting resin composites by optimizing the transport channels. To implement this strategy, conventional graphene nanoplatelet/thermosetting resin is crushed into micron-sized composite powders, which are mixed with graphene nanoplatelets to form novel complex fillers to prepare the self-composited materials with thermosetting resins. A highly conductive compact graphene layer is formed on the surface of the crushed composite powders, while the addition of the micron-sized powder induces the orientation of graphene nanoplatelets in the resin matrix. Therefore, a highly conductive network is constructed inside the self-composited material, significantly enhancing the electrical conductivity. The composite materials based on epoxy resin, cyanate resin, and unsaturated polyester are prepared with this method, reflecting that the method is universal for preparing composites based on thermosetting resins. The highest electrical conductivity of the self-composited material based on unsaturated polyester is as high as 25.9Sm-1 . This self-compositing strategy is simple, efficient, and compatible with large-scale industrial production, thus it is a promising and general way to enhance the conductivity of thermosetting resin matrix composites.

Effects of Accelerated Aging on Thermal, Mechanical and Shape Memory Properties of Cyanate-Based Shape Memory Polymer: III Vacuum Thermal Cycling.

Shape memory polymers (SMPs) with intelligent deformability have shown great potential in the field of aerospace, and the research on their adaptability to space environments has far-reaching significance. Chemically cross-linked cyanate-based SMPs (SMCR) with excellent resistance to vacuum thermal cycling were obtained by adding polyethylene glycol (PEG) with linear polymer chains to the cyanate cross-linked network. The low reactivity of PEG overcame the shortcomings of high brittleness and poor deformability while endowing cyanate resin with excellent shape memory properties. The SMCR with a glass transition temperature of 205.8 °C exhibited good stability after vacuum thermal cycling. The SMCR maintained a stable morphology and chemical composition after repeated high-low temperature cycle treatments. The SMCR matrix was purified by vacuum thermal cycling, which resulted in an increase in its initial thermal decomposition temperature by 10-17 °C. The continuous vacuum high and low temperature relaxation of the vacuum thermal cycling increased the cross-linking degree of the SMCR, which improved the mechanical properties and thermodynamic properties of SMCR: the tensile strength of SMCR was increased by about 14.5%, the average elastic modulus was greater than 1.83 GPa, and the glass transition temperature increased by 5-10 °C. Furthermore, the shape memory properties of SMCR after vacuum thermal cycling treatment were well maintained due to the stable triazine ring formed by the cross-linking of cyanate resin. This revealed that our developed SMCR had good resistance to vacuum thermal cycling and thus may be a good candidate for aerospace engineering.

Preparation and Appraisal of High‐Modulus Resin‐Based Composites Reinforced by Silica‐Coated Multi‐Walled Carbon Nanotubes

AbstractStructural materials for satellites call for reliant stiffness while meeting the requirements of strength. Cyanate resins with superior mechanical properties and reliable dimensional stability have come under the light in the aerospace field. Herein, TDE‐86 epoxy resin was adopted to modify bisphenol E cyanate resin to prepare a high‐performance composite matrix with superior mechanical properties, low molding temperature and adequate toughness. The silica‐coated carboxylated multi‐walled carbon nanotubes (SiO2@MWCNT) was designed and synthesized by sol‐gel method for the reinforced preparation of high‐modulus cyanate/epoxy composites. The experiment results demonstrated that the mechanical properties of the resin matrix could be effectively enhanced by the introduction of SiO2@MWCNT, and the optimal overall performance was achieved with 0.9 wt% SiO2@MWCNT. Compared with unmodified resin matrix, the incorporation of SiO2@MWCNT contributes a large increase in the storage modulus and glass transition temperature. Benefit from the addition of nanomaterials, the curing temperature and viscosity of cyanate resin modified by epoxy resin were further reduced to nearly 70 °C and 40 mPa ⋅ s, which makes the composite matrix retain excellent processing properties.

The performance characterization of carbon fiber–reinforced plastic for space applications

In this paper, the excellent dimensional stability and vacuum outgassing of high-performance carbon fiber–reinforced plastic (CFRP) were discussed. First, the high-performance resin matrix was obtained by modifying cyanate resin, and the modified cyanate ester was used to make prepreg and laminates. Then, the mechanical property retention rate of laminates reached 90.79% under proton and electron irradiation. The average values of total mass loss and collected volatile condensable material of high-performance CFRP were 0.116% and 0.008%, respectively. Finally, the candidate tube and frame were fabricated based on the ply lay-up design. The candidate tube and frame were subjected to a series of experiments of thermal deformation and hygroscopic deformation to verify the dimensional stability. The thermal deformations of the tube and frame reached 0.468 μm/m and 4.579 μm/m, respectively, with a temperature variation of 4°C. The measured hygroscopic deformation of the tube reached 8.16 μm/m in nearly 3 months. The experimental results show that the high-performance CFRP can be used for precision optical structures of space telescopes.

Design, preparation, and performance characterization of low temperature environment-resistant composite resin matrix in rocket fuel

Cryogenic technology is a vital part of our society, not only in our lives, but also in the field of cutting-edge technology. The research and application of cryogenic technology is involved in many important projects in many countries and even in the world, such as aviation, aerospace, energy, transportation, and medicine. With its high specific strength and high specific modulus, carbon fiber reinforced resin matrix composite materials have gradually become the key material for aerospace vehicles, with significant advantages in reducing structural weight and improving structural efficiency. However, in the ultra-low temperature environment such as liquid hydrogen and liquid oxygen, the overall structure of carbon fiber reinforced resin matrix composites is severely tested by the environment, and it is extremely important to evaluate the mechanical properties of the composites under ultra-low temperature due to the difference of their material structure and properties from those of traditional materials, and the difference of thermal expansion coefficients between the reinforcing material carbon fiber and the resin matrix in rocket fuel. In this paper, the epoxy resin-based composite system was prepared by modifying TDE-85 epoxy resin with low-viscosity cyanate resin through molecular structure design, which is suitable for ultra-low temperature environment. The surface tension and dynamic contact angle of the modified epoxy resin are better than those of the pure epoxy resin, and it can form a good infiltration with carbon fiber and the interfacial properties of the composite are excellent. Secondly, the modified epoxy resin-based composite unidirectional plate was prepared by wet winding molding process, and the low-temperature mechanical property test specimens were prepared according to the relevant test standards. The mechanical properties were tested at −196℃, −150℃, −90℃ and room temperature 25℃ to obtain the low-temperature mechanical properties of the composite system, which provided the basis for the design of the composite system in the ultra-low temperature environment. Finally, the microstructure of the epoxy matrix composites was characterized by SEM method after the different temperature tests. The material structure, morphology, and composition were characterized by field emission scanning electron microscopy (FESEM, M400 FEI) with energy dispersive X-ray spectroscopy (EDS). In this paper, TDE-85 epoxy resin was modified with low viscosity cyanate resin to produce a modified epoxy resin suitable for ultra-low temperature environment, and the process properties of the epoxy resin were characterized. The surface tension of the modified epoxy resin was 43.405 mN/m, which was significantly lower than that of the pure epoxy resin at room temperature of 48.814 mN/m. Therefore, the modified epoxy resin had better flowability and required less time to wet the fibers during the molding process, resulting in higher molding efficiency.

Calcia-doped ceria hybrid coating functionalized PBO fibers with excellent UV resistance and improved interfacial compatibility with cyanate ester resins

Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers display weak outdoor stability and reliability due to their poor UV resistance and chemically inert surface. In this work, calcia-doped ceria (Ce0.8Ca0.2O1.8) nanoparticles was fabricated via chemical co-precipitation method, and the novel Ce0.8Ca0.2O1.8/P(S-co-BCB-co-MMA) organic–inorganic hybrid coating was then designed and prepared for surface functionalization of PBO fibers (PBO@P-Ce0.8Ca0.2O1.8). Organic-inorganic hybrid coating presents high surface roughness and excellent UV resistance. When the concentration of Ce0.8Ca0.2O1.8 nanoparticles with the particle size of about 50 nm is 0.6 wt%, PBO@P-Ce0.8Ca0.2O1.8–3 fibers (sample 4, 0.6 wt%) present the best interfacial bonding strength with modified bisphenol A cyanate (BADCy) resins, the single fiber pull-out strength between sample 4 and modified BADCy resins reaches the maximum value of 4.6 MPa, 48.4% higher than that of pristine PBO fibers (sample 0, 3.1 MPa). Meanwhile, the tensile strength of sample 4 after 288 h UV aging is increased from 1.4 GPa (PBO fibers) to 4.1 GPa. Overall, functionalized PBO fibers in this work demonstrate higher surface activity, excellent UV resistance and improved interfacial bonding strength with modified BADCy resins, which provides a new idea for functionalizing the surface activity and UV resistance of high-performance polymer fibers.

Fabrication and Characterization of a Modified Conjugated Molecule-Based Moderate-Temperature Curing Epoxy Resin System

2-methylimidazole derivative (EGE-2MI) was synthesized through the reaction of ethyl glycidyl ether (EGE) with conjugated molecule 2-methylimidazole (2-MI). The structure was confirmed by Fourier transform infrared spectroscopy (FTIR)、1H-nuclear magnetic resonance spectroscopy (1H-NMR) and differential scanning calorimeter (DSC). The synthesized EGE-2MI was applied in epoxy resin E-51 as latent curing agent. Kinetics of the curing reaction were studied by DSC method, optimum curing process parameters were determined, storage life of the resin system at room temperature was evaluated, mechanical properties of the moderate-temperature cured products were also tested and analyzed. The results revealed that epoxy resin system using EGE-2MI as curing agent can be efficiently cured at 110~120 °C, with an activation energy of 86.34 kJ/mol. The storage period of EGE-2MI/ Cyanate resin (CE) system can reach 14 days under ambient temperature. In addition, the cured mixture with EGE-2MI/CE has a tensile strength of 40 MPa and an Al-Al adhesion shear strength of 20.11 MPa.

Life-cycle evaluation of the moisture absorption and desorption behaviors of prepreg-based carbon fiber reinforced plastic

Moisture absorption and desorption by a matrix resin, and the resulting deformation, exert a critical adverse effect on the shape stability of carbon fiber reinforced plastic (CFRP) space structures. This study evaluates the effect of the moisture content of prepreg sheets on the life-cycle behavior of the prepreg-based CFRP. After evaluating the moisture absorption and desorption characteristics of the prepreg sheets, the cure-induced strain and moisture absorption and desorption deformations were measured, employing embedded optical fiber sensors. Furthermore, to investigate the relationship between the moisture absorption and desorption behaviors and the chemical structure of the matrix resin, its structure was analyzed by Fourier-transform infrared spectroscopy (FTIR). Since absorption and desorption are dependent on the matrix resin, two types of resins were evaluated: epoxy resin and a low moisture absorption cyanate resin. Finally, recommendations for the manufacture and operation of CFRP space structures are offered, with respect to maintaining their long-term shape stability.

Synthesis and characterization of divinylbenzene-based cyanate resin and its quartz fiber-reinforced composite

Cyanate ester (CE) resins are important polymeric materials with excellent dielectric properties, low moisture absorption, and good heat resistance, which have shown great superiority for use in electronic and aerospace industries. In this article, a novel CE resin was designed and synthesized from divinylbenzene. The proposed structures were characterized with Fourier transform infrared spectroscopy, gel permeation chromatography, and mass spectrometry. The chemical reaction activity, heat resistance, dielectric properties, and water adsorption of the synthesized CE derived from divinylbenzene (DVBCy) were examined and compared with the traditional bisphenol A and bisphenol M (4,4′-[1,3-phenylenebis(1-methyl-ethylidene)]bisphenol)-based CE. The DVBCy resin exhibits a glass transition temperature ( T g) of 162.7°C, a dielectric constant of 2.61, a dielectric loss tangent angle of 0.0035 at about 10 GHz, and a lower water absorption of 0.77%. Compared with the bisphenol M type CE, DVBCy resin provides slightly superior dielectric properties, higher mechanical properties, more favorable process technology for prepreg construction, and lower costing. The DVBCy blend resin modified with bisphenol A-based CE and core–shell particles possesses suitable rheological properties, and the corresponding quartz fiber-reinforced composite exhibits excellent mechanical as well as dielectric properties.

Random copolymer membrane coated PBO fibers with significantly improved interfacial adhesion for PBO fibers/cyanate ester composites

Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers possess excellent dielectric, mechanical properties and heat resistance. However, the surface of PBO fibers is smooth and highly chemical inert, resulting in poor interfacial compatibility to polymer matrix, which severely limits its wider application in high-performance fiber-reinforced resin matrix composites. In this work, random copolymers (P(S-co-BCB-co-MMA)) containing benzocyclobutene in the side-chain were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, which were then utilized to form dense random copolymer membrane on the surface of PBO fibers by thermally cross-linking at 250 °C (PBO@P fibers). Four kinds of synthesized P(S-co-BCB-co-MMA) with different number-average molar mass (Mn) were well controlled and possessed narrow dispersity. When the Mn was 32300, the surface roughness of PBO@P fibers was increased from 11 nm (PBO fibers) to 39 nm. In addition, PBO@P fibers presented the optimal interfacial compatibility with bisphenol A cyanate (BADCy) resins. And the single fiber pull-out strength of PBO@P fibers/BADCy micro-composites was 4.5 MPa, increasing by 45.2% in comparison with that of PBO fibers/BADCy micro-composites (3.1 MPa). Meantime, PBO@P fibers still retained excellent tensile strength (about 5.1 GPa). Overall, this work illustrates a simple and efficient surface functionalization method, which would provide a strong theoretical basis and technical support for controlling the surface structure & chemistry of inert substrates.

Fluorine/adamantane modified cyanate resins with wonderful interfacial bonding strength with PBO fibers

Novel compound (AEAF) with both cage-type adamantanes and fluorine-containing structures was synthesized from bisphenol AF, 1-adamantyl chloride and epichlorohydrin through successive esterification and O-alkylation reaction, which was then introduced into the curing networks of bisphenol A cyanate ester (BADCy) resins through copolymerization, to obtain AEAF-co-BADCy resins. AEAF presented low polarizability & dipole density, rigid cage adamantane, and stable CF3 group. When the mass fraction of AEAF was 6 wt%, AEAF-co-BADCy resins displayed the minimum real part (ε′r), imaginary part (ε”r) of complex permittivity, and dielectric loss tangent (tanδ) values, which were 2.49, 0.012, and 0.0048, respectively. And the corresponding wave transmission efficiency (T) was 92.3%, significantly higher than that of pure BADCy (86.6%). AEAF-co-BADCy resins also possessed excellent mechanical properties and better interfacial compatibilities with poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers. The corresponding flexural strength (126.5 MPa) and impact strength (15.2 kJ m−2) were increased by 16.6% and 47.6%, in comparison to pure BADCy (flexural strength of 108.5 MPa and impact strength of 10.3 kJ m−2). Meantime, the single fiber pull-out strength of PBO fibers/AEAF-co-BADCy (6 wt% AEAF) micro-composites also displayed an increase from 3.1 MPa (PBO fibers/BADCy) to 3.4 MPa.

Preparation of phosphorus-containing cyanate resin with low curing temperature while excellent flame resistance and dielectric properties

A novel cyanate resin was prepared by the reaction of 10-(2,5-Dihydroxyphenyl)-10-H-9-oxa-10-phospha-phenantbrene-10-oxide (DOPO-HQ) and 2, 2-Bis (4-cyanatophenyl) propane (BACY) when trace of cobalt(III) acetylacetonate(CoAt(III)) was added, The curing behavior during the reaction of DOPO-HQ/BACY/CoAt(III) system was analyzed by gelation time (GT), differential scanning calorimetry (DSC) and Fourier transformation infrared spectrometry (FTIR), respectively. Compared with the BACY/CoAt(III) system (GT = 1239 s, Tp (exothermic peak temperature) = 215 °C), the GT of DOPO-HQ/BACY/CoAt(III) system is 110 s at 180 °C, and the Tp is 154 °C when containing 10 wt % DOPO-HQ. The limit oxygen index (LOI) and vertical burning test (UL-94) demonstrate that the flame retardancy of BACY resin is improved by DOPO-HQ. Specifically, the DOPO-HQ/BACY resin prepared by a mass ratio of DOPO-HQ: BACY = 10:90 has a LOI value of 33.1% and a UL-94 of V-0 rating, while the LOI value of BACY resin is 28.5% and UL-94 is no rating. In addition, the DOPO-HQ/BACY resin containing 10 wt % DOPO-HQ has excellent dielectric properties, the dielectric constant (Dk) is 2.69 and dielectric loss (Df) is 0.007. The as-synthesized DOPO-HQ/BACY resin shows promising application prospect as electronic packaging materials.

Fabrication and investigations of G-POSS/cyanate ester resin composites reinforced by silane-treated silica fibers

Modified cyanate resins (G-CE) and functionalized silica fibers (K-SFs) were obtained by introducing glycidyl polyhedral oligomeric silsesquioxane (G-POSS) and γ-aminopropyltriethoxy silane coupling agent (KH-550), respectively. G-CE and K-SFs were then used to fabricate K-SFs/G-CE wave-transparent composites. The activation energy of the G-CE blends decreased to 49.80 kJ/mol, which led to a decrease in the curing temperature from 274 °C to 254 °C. The contact angle of the functionalized silica fibers increased considerably to 107.4°; this modified the interfacial compatibility, which enhanced the mechanical properties. The K-SFs/G-CE composite had a maximum flexural strength of 548.1 MPa and flexural modulus of 19.3 GPa, which were increases of 86.7% and 48.5% compared to the corresponding values of SFs/CE composite (flexural strength of 293.5 MPa and flexural modulus of 13.0 GPa). In addition, the ε and tanδ of the K-SFs/G-CE composite decreased to 2.63 and 3.3 × 10−3, respectively, which were respective decreases of 6.5% and 23.0% compared with the corresponding values of SFs/CE composite (ε of 2.76 and tanδ of 4.6 × 10−3). Hence, the resulting K-SFs/G-CE composites are good candidate materials for high performance wave-transparent composites.

Curing Kinetics of Cyanate Resin Modified by ESi

The kinetics of the curing reaction of cyanate resin modified by ESi was studied using DSC. The apparent activition energy, reaction order and frequency factor of the curing reaction of the resin were obtained as being E=68.58kJ mol-1, A=2992.06 s-1, n=0.89 respectively. In addition, the gel point, setting point, post cure temperature of this resin was found to be at 149.40°C, 180.72°C, 238.98°C.

Triptycene-Based Microporous Cyanate Resins for Adsorption/Separations of Benzene/Cyclohexane and Carbon Dioxide Gas.

Triptycene-based cyanate monomers 2,6,14-tricyanatotriptycene (TPC) and 2,6,14-tris(4-cyanatophenyl)triptycene (TPPC) that contain different numbers of benzene rings per molecule were synthesized, from which two microporous cyanate resins PCN-TPC and PCN-TPPC were prepared. Of interest is the observation that the two polymers have very similar porosity parameters, but PCN-TPPC uptakes considerably higher benzene (77.8 wt %) than PCN-TPC (17.6 wt %) at room temperature since the higher concentration of phenyl groups in PCN-TPPC enhances the π-π interaction with benzene molecules. Besides, the adsorption capacity of benzene in PCN-TPPC is dramatically 7 times as high as that of cyclohexane. Contrary to the adsorption of organic vapors, at 273 K and 1.0 bar, PCN-TPC with more heteroatoms in the network skeleton displays larger uptake of CO2 and higher CO2/N2 selectivity (16.4 wt %, 60) than those of PCN-TPPC (14.0 wt %, 39). The excellent and unique adsorption properties exhibit potential applications in the purification of small molecular organic hydrocarbons, e.g., separation of benzene from benzene/cyclohexane mixture as well as CO2 capture from flue gas. Moreover, the results are helpful for deeply understanding the effect of porous and chemical structures on the adsorption properties of organic hydrocarbons and CO2 gas.

Synthesis and properties of cyanate mixed resin systems modified by polyphenylene oxide for production of high-frequency copper clad laminates

A redistributed polyphenylene oxide (rPPO) was synthesized and used to modify cyanate resin (CE) to give cured rPPO/CE mixed resin systems, whose molecular weight and chemical composition were analyzed by Gel Permeation Chromatography (GPC) and Fourier Transform Infrared Spectroscopy (FT-IR). The mechanical, thermal conductivity and dielectric properties of these mixed resin systems were measured, with the rPPO containing 20 wt% bisphenol A (BPA) having a number-average molecular weight as low as 2653. The glass transition temperature (Tg) of cured rPPO/CE mixed resin systems was decreased significantly (lowest value − 230 °C) when compared with pure cured cyanate resin containing 1 wt% epoxy resin. The bending strength of cured resin was decreased when low molecular weight PPO (lowest value − 46.84 MPa) was employed as a substrate. These new cured rPPO/CE mixed resin systems exhibited a low dielectric constant of 3.85/107 Hz, a low dielectric loss of 2.64 × 10−3/106 Hz, and a low thermal diffusivity of 0.143 m2/s, that indicates they may be useful for the preparation of CCLs for electronics applications.