Arylacetylene Resin Research Articles

Construction of activated carbon-supported B3N3 doped carbon as metal-free catalyst for dehydrochlorination of 1,2-dichloroethane to produce vinyl chloride.

Dehydrochlorination of 1,2-dichloroethane (1,2-DCE) is an important oil-based way for the industrial production of vinyl chloride monomer (VCM), but has proved to be plagued by a high operating temperature and low efficiency. Therefore, environmentally friendly and metal-free catalysts are in high demand for green chemical processes. In view of the stronger electronegativity of borazine (B3N3) and convenience of constructing a two-dimensional structure because of the coplanarity of B3N3, the acetenyl group, and the benzene ring, herein, we report a novel controllable B3N3 doped activated carbon (B,N-ACs) synthesized using B3N3-containing arylacetylene resin for dehydrochlorination of 1,2-DCE. The result is activated carbon loaded with B3N3-doped carbon nanosheets on the surface due to the B3N3-containing arylacetylene resin grown on the surface of activated carbons. The B,N-ACs deliver excellent catalytic performance, with a 1,2-DCE conversion of ∼92.0% and VCM selectivity over 99.9% at 250 °C, significantly higher than that of the current catalysts in the industry. The results further verified that pyridinic-N and the internal B3N3 play significant roles in this catalysis. The new green, metal-free B,N-ACs with excellent catalytic efficiency make it a promising catalyst for dehydrochlorination of 1,2-DCE to produce VCM.

Effects of pendant side groups on the properties of the silicon-containing arylacetylene resins with 2,5-diphenyl-[1,3,4]-oxadiazole moieties.

Silicon-containing arylacetylene resins with rigid conjugated structures in the main chain often exhibit poor processability. A strategy of improving the processability by destroying the molecular structure symmetry using side aromatic groups was proposed, and the effects of the side groups was further explored. Two novel structural resins with side aromatic phenyl and phenylacetylene groups (PODSA-2P-MM and PODSA-2E-MM) were synthesized by Grignard reaction. The side aromatic groups strongly interfere with the regular arrangement of the main chains, and the crystallinities of the resins decrease as compared with PODSA-MM resin without side aromatic groups. Due to the influence of the side aromatic groups, the novel resins exhibit good processability, low exothermic enthalpy, high modulus and good heat resistance.

The synthesis and properties of silicon-containing arylacetylene resins with rigid-rod 2,5-diphenyl-[1,3,4]-oxadiazole moieties

The silicon-containing arylacetylene resins with 2,5-diphenyl-[1,3,4]-oxadiazole moieties (PODSA-MM, PODSA-MP and PODSA-PP) in the main chains were synthesized by Grignard reactions and characterized by protonnuclearmagneticresonance (1H NMR) spectroscopy, fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetricanalysis (TGA). The results show that the resins have good solubility, processability, low water absorption, good thermal and mechanical properties. The resins could be cured at a temperature lower than 200 °C. The flexural strength and modulus of the cured PODSA-MP resin at room temperature are 69.6 MPa and 2.5 GPa, respectively. T300 carbon fibre cloth reinforced PODSA-MP resin composite shows high flexural strength (673 MPa) and modulus (64.4 GPa) as well. The temperatures at 5% weight loss (Td5) of the cured resins are higher than 450 °C in nitrogen and air.

Star-shaped arylacetylene resins derived from silicon

Abstract Star-shaped arylacetylene resins, tris(3-ethynyl-phenylethynyl)methylsilane, tris(3-ethynyl-phenylethynyl) phenylsilane, and tris (3-ethynyl-phenylethynyl) silane (TEPHS), were synthesized through Grignard reaction between 1,3-diethynylbenzene and three types of trichlorinated silanes. The chemical structures and properties of the resins were characterized by means of nuclear magnetic resonance, fourier-transform infrared spectroscopy, Haake torque rheomoter, differential scanning calorimetry, dynamic mechanical analysis, mechanical test, and thermogravimetric analysis. The results show that the melt viscosity at 120 °C is lower than 150 mPa⋅s, and the processing windows are as wide as 60 °C for the resins. The resins cure at the temperature as low as 150 °C. The good processabilities make the resins to be suitable for resin transfer molding. The cured resins exhibit high flexural modulus and excellent heat-resistance. The flexural modulus of the cured TEPHS at room temperature arrives at as high as 10.9 GPa. Its temperature of 5% weight loss (T d5) is up to 697 °C in nitrogen. The resins show the potential for application in fiber-reinforced composites as high-performance resin in the field of aviation and aerospace.

Improvement of the oxidation resistance of silicon‐containing arylacetylene resins upon the introduction of carbazoles

AbstractSilicon‐containing arylacetylene resins (PSAs) can be used in high temperature environment due to their excellent thermal stability. However, their high temperature oxidation is still bottle‐neck for further application. Herein, Materials Genome Initiative (MGI) was utilized to identify a target monomer, 3,6‐diethynylcarbazole (DEC), to design new PSAs with enhanced antioxidant properties and heat resistance. After incorporation of DEC, the thermal curing behavior observed using differential scanning calorimetry (DSC), fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) revealed that obtained silicon‐containing carbazolylacetylene resins (PSA‐VBC) can exhibit hydroamination reaction to decrease the initial curing temperature. And the temperature at 5% weight loss (Td5) occurred in cured copolymers ranged from 665°C to 691°C, which showed excellent heat resistance. Moreover, the oxidation behavior of cured resins was investigated by thermogravimetric/derivative thermogravimetry (TG/DTG), X‐ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Upon the incorporation of DEC, the thermal oxidation decomposition temperature of PSA‐VBC were 100°C higher than those observed for PSAs, which also proved by XPS analysis results that the oxygen content of PSA‐VBC solidified oxide was lower than that of PSAs. In addition, the surface morphology of cured PSA‐VBC resins still maintained integrity after oxidation at 400°C for 2 hr, which showed excellent oxidation resistance.

Synthesis and Performance of Fluorine-Containing Silicon Arylacetylene Resins

Synthesis and Performance of Fluorine-Containing Silicon Arylacetylene Resins

Developing Highly Tough, Heat-Resistant Blend Thermosets Based on Silicon-Containing Arylacetylene: A Material Genome Approach.

Silicon-containing arylacetylene (PSA) resins exhibit excellent heat resistance, yet their brittleness limits the applications. We proposed using acetylene-terminated polyimides (ATPI) as an additive to enhance the toughness of the PSA resins and maintain excellent heat resistance. A material genome approach (MGA) was first established for designing and screening the acetylene-terminated polyimides, and a polyimide named ATPI was filtered out by using this MGA. The ATPI was synthesized and blended with PSA resins to improve the toughness of the thermosets. Influences of the added ATPI contents and prepolymerization temperature on the properties were examined. The result shows that the blend resin can resist high temperature and bear excellent mechanical properties. The molecular dynamics simulations were carried out to understand the mechanism behind the improvement of toughness. The present work provides a method for the rapid design and screening of high-performance polymeric materials.

A Novel Zirconium Modified Arylacetylene Resin: Preparation, Thermal Properties and Ceramifiable Mechanism

With the rapid development of thermal protection systems for the aerospace industry and power electronics, polyarylacetylene (PAA) resin plays an important role because of its good mechanical properties, high glass transition temperature (Tg), low water absorption, high char yield (Yc), and the fact that there is no byproduct released in the curing process. In order to further improve the thermal property of PAA based FRP for the thermal protection field, the introduction of a zirconium element into arylacetylene is promising. In this paper, zirconium modified arylacetylene (ZAA) resin was prepared by two-step synthesis. The FTIR analysis characterized its molecular structure and confirmed the products. The viscosity of ZAA was about 6.5 Pa·s when the temperature was above 120 °C. The DSC analysis showed that the ZAA had a low curing temperature, and its apparent activation energy was 103.86 kJ/mol in the Kissinger method and 106.46 kJ/mol in the Ozawa method. The dielectric constant at 1 MHz of poly(zirconium modified arylacetylene) (PZAA) was 3.4. The TG analysis showed that the temperatures of a weight loss of 5% (Td5) and char yield (Yc) at 800 °C of PZAA were 407.5 °C and 61.4%, respectively. The XRD results showed the presence of SiO2 and ZrO2 in the PZAA residue after ablation. The XRF results showed that the contents of SiO2 and ZrO2 in PZAA residual after ablation were, respectively, 15.3% and 12.4%. The SEM showed that the surface of PZAA after ablation had been covered with a dense and rigid ceramic phase composed of ZrO2 and SiO2. Therefore, the introduction of Zr into arylacetylene greatly improved the densification of the surface after ablation, and improved the heat resistant property.

Synthesis and Properties of a Silicon‐Containing Arylacetylene Resin with 2,6‐Diphenoxypyridine Unit

AbstractA novel silicon‐containing arylacetylene resin called poly(dimethylsilylene‐ethylene‐phenoxypyridyloxy‐phenylene‐ethylene) (PSPPY) was made from 2,6‐bis(4‐ethynyl‐phenoxy) pyridine and dimethyldichlorosilane by Grignard reactions. The structure and properties of the resin were characterized by 1H‐NMR, FT‐IR, GPC, XRD, DSC, TGA and universal testing machine. The resin has a wide processing window ranged from 35 °C to 155 °C. The cured resin shows excellent mechanical property, low dielectric property and high thermal stability. The flexural strength of the cured resin at room temperature reaches 58.7 MPa. The cured resin has dielectric constant 3.0–3.5, dielectric loss 0.008‐0.040 in the frequency of 10−1‐106 Hz, and low water uptake (0.8 %). The degradation temperature at 5 % weight loss and the residue at 800 °C of the cured resin arrive at 500 °C and 77.1 % in nitrogen atmosphere, respectively.

Preparation and Properties of Poly (Silicon-Containing Arylacetylene)/Attapulgite Foams

Poly(silicon-containing arylacetylene) (PSA) syntactic foams were prepared by thermally expandable microspheres (EM) in the silicon-containing arylacetylene (SA) resin during curing. The morphology, porosity, thermal and mechanical properties of the foams were studied. Furthermore, the PSA foam was reinforced by attapulgite (ATT) nanoparticles to fabricate the PSA/ATT composite foam. The results display that the density, compressive strength and thermal stability of the PSA foam decrease with increasing EM content in the matrix, but the temperature at 5% weight loss in N2 is still higher than 560°C, and the residual yield at 800°C is larger than 89%. With addition of 10 g ATT in the 100 g matrix, the average specific compressive and flexural strength of PSA/ATT foam are 31.4 MPa g-1cm3 and 33.6 MPa g-1cm3, respectively. The thermal conductivity of the composite foam can decrease to 0.064 W m-1 K-1 and has a density of 319 kg m-3.

Study on the Interface of Acetylene Silazane (SZ) Modified QF/PSA Composites

Due to the excellent thermo-stability, ablation resistance and superior dielectric properties, poly-silicon-containing arylacetylene resin (PSA) shows a promising application in aerospace and spaceflight industries as a composite matrix with quartz fiber (QF). However, the non-polar nature of PSA hamper the interfacial interaction with the QF resulting in a relatively weak mechanical strength for the whole QF/PSA composites. This can be alleviated by incorporating a coupling agent between QF and PSA to reinforce their interaction. Here, new coupling agents, three ethynyl silazane derivatives, were synthesized to improve QF/PSA composite mechanical properties and named as bis (3-ethynylaniline)-diphenylsilane (SZPP), bis (3-ethynylaniline)-methylphenylsilane (SZMP) and bis (3-ethynylaniline)-phenylvinylsilane (SZPV). For SZPP, about 3.0 wt% addition of this coupling agent increased the interlaminar shear strength and flexural strength of QF/PSA composite by 21.2% and 18.4%, respectively, compared with the untreated composite. Meanwhile, among the three coupling agents, SZPV showed the best improvement in enhancing the interlaminar shear strength and flexural strength of QF/PSA composites, which reached 34.1% and 41.7%, respectively.

Star‐shaped silicon‐containing arylacetylene resin based on a one‐pot synthesis using zinc powder catalysis with improved processing and thermal properties

ABSTRACTHerein, reporting a simple, sustainable, and cost‐effective chemical synthesis of a star‐shaped silicon‐containing arylacetylene (SSA) resin via a one‐pot process using zinc powder as a catalyst. The as‐prepared viscous liquid resins exhibited moderate rheological behavior. The thermal curing temperature was determined to be 203 °C using differential scanning calorimetry, which is much lower than that reported for polyimide and phthalonitrile (>300 °C), indicating the SSA resins are suitable for processing at a lower temperature. Thermogravimetric analysis also revealed the excellent thermal stability and extremely high carbon residue of the cured SSA resin (the temperature at 5% mass loss and residual yield at 800 °C under N2 were 654 °C and 93%, respectively). The results showed the excellent processability and thermal stability of SSA resin. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48248.

Oligomeric phthalonitriles and tetrakis(phenylethynyl)benzene blends with improved processing and thermal properties

ABSTRACTBlended resins were prepared from the resorcinol‐based PEEK‐like oligomeric phthalonitrile resin (RES) and tetrakis(phenylethynyl)benzene (TPEB), a high char yield arylacetylene resin. Initial probing of curing properties using differential scanning calorimetry, indicated that TPEB and RES co‐cure when heated. Characterization of thermal properties using thermogravimetric analysis indicated that a 1:1 TPEB‐RES blend (by weight) exhibited a char yield of 80% which was 6% larger compared to pure RES (74%). According to FTIR characterization, the enhanced thermal properties of TPEB‐RES were the result of increased crosslinking density. Rheological studies of TPEB, RES, and TPEB‐RES blends indicated that blended systems exhibit similar processing characteristics as RES resin. For example, resins display ideal viscosities and relatively large processing windows when cured at 175 °C. Alternatively, pure TPEB resin exhibits low viscosities when melted, which are not suitable for preparing composite materials. This study indicates that preparing TPEB‐RES blends is an effect strategy for improving thermal performance of potential RES composites while still maintaining the required processability for fabrication of dense polymer composites. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2630–2640

Preparation and Properties of Modified Silicon-containing Arylacetylene Resin Composite Reinforced by Carbon Fiber Cloth

Preparation and Properties of Modified Silicon-containing Arylacetylene Resin Composite Reinforced by Carbon Fiber Cloth

Synthesis of Branched Silicon-Containing Arylethyleneacetylene Resin and the Performance of Casting

With good thermal properties, dielectric property and high-temperature ceramics performance, silicon-containing arylacetylene resin (PSA) has opened an attractive alternative to high performance thermosetting resins in application in the area of aircraft and missile. However, it is difficult to introduce silicon into the main chain of organic arylacetylene. In this paper, branched silicon-containing arylethyleneacetylene (BSA) resin was synthesized by methyltrichlorosilane and diethynylbenzene with zinc powder as catalyst. The advantages lie in simple operation, short reaction period and mild heat release. BSA resin exhibits excellent processability with the processing temperature of 20?C - 150?C and processing window of 130?C. The glass transition temperature of the resin casting is over 500?C. The temperature of 5% weight loss (Td5) is up to 575?C and char yield of thermoset at 800?C (Y800) reaches 91% under nitrogen. Also, the dielectric constant and dielectric loss of casting has no change within 10 - 106 Hz.

Thermal curing and degradation behaviour of silicon-containing arylacetylene resins

Silicon-containing aryacetylene resins (PSAs) have already shown potential application as heat-resistant materials due to their excellent thermal stability. The formation and degradation of structures in cured PSAs are very important to evaluate the thermal properties during their applications. Herein, the thermal curing and degradation behavior of PSAs with different substituents were investigated by DSC, FT-IR, Py-GC-MS, TGA and TG-GC-MS. DSC and FT-IR analysis reveals that the curing reaction is dominated by the crosslinking reaction of CCH and SiCC, meanwhile, the reactive substituents (such as SiH and SiCHCH2) could promote the CCH and SiCC reaction with higher conversion. Py-GC-MS was used to detect the pyrolysis products at 650 °C and 750 °C, respectively, and the results could provide important information about the curing reaction and structures of cured PSAs. The curing reaction of PSAs mainly contains cyclotrimerization and Diels-Alder reaction of CCH and SiCC, and some addition reaction to form polyene structure. The main structures in cured PSAs contain a lot of phenyl rings, some aromatic fused rings and a little of polyene structure, moreover, their contents in cured PSAs are dependent on the substituents of the precursors. The TGA results show that the substituents of SiH and SiCHCH2 can effectively improve the crosslinking index of the cured PSA-H and PSA-V, and endow them with better thermal stability. Additionally, the degradation behavior of cured PSAs have been well studied by TG-GC-MS. When the temperature is 400 °C, the SiCH3 and some aliphatic structure begin to degrade and form CH4, and with the temperature increasing to 500 °C, the unsaturated and aliphatic structures decompose into C2H4 and C2H6, and after 600 °C, the aromatic rings and fused rings in cured PSAs are dehydrogenated and release H2. In addition, the content of the degradation products and their forming temperature are also related with the substituents.

The strengthening and toughening effects of a novel octa(propargyl propyl sulfide) POSS (OPPSP) on silicon-containing arylacetylene (PSA) resin

A novel octa(propargyl propyl sulfide) POSS (OPPSP) was synthesized by the thiol-halogen reaction between octa(mercaptopropyl) POSS (POSS-SH) and propargyl chloride under phase transfer catalysis. Furthermore, OPPSP was employed as a reinforcing agent to prepare a modified silicon-containing arylacetylene (OPPSP-PSA) resin. The resulting OPPSP-PSA thermoset with 10wt% of OPPSP exhibits 80.5% and 92.8% increment in flexural strength and impact fractured energy as compared to pristine PSA thermoset. Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) are used to observe the dispersion of OPPSP in the fractured surfaces of samples. The results show that both the nano-dispersion of POSS cages and the POSS-enriched “particles” are possible mechanisms behind the improved mechanical properties.

Synthesis and Characteristic of Borazine-Silicon-Containing Arylacetylene Resin

Borazine-silicon-containing arylacetylene (PBZSA) resin was a novel organic inorganic hybrid polymer and prepared through condensation reaction among B,B’,B’’-trichloroborazine, dichlorosilane and arylacetylene Grignard reagent. The chemical structure of PBZSA resin was characterized by FT-IR and 1H NMR. The thermal stability and dielectric properties of cured PBZSA were investigated by TGA and broadband dielectric spectrometer. The results indicated that cured PBZSA showed high thermal stability with char yield up to 87.1% at 1000°C and at decompose temperature (Td5) 580°C, and low dielectric constant (2.8-2.9) and dielectric loss (<0.005).

Borazine-containing arylacetylene resin as low dielectric constant materials

A novel borazine-containing arylacetylene resin (PBZA) has been synthesized in high yield through condensation reaction between B,B′,B″-trichloroborazine and arylacetylene Grignard reagent, which are potential candidates as low dielectric constant material for microelectronic packaging and also radio and microwave frequency substrate. The PBZA is a brown viscous liquid and soluble in a variety of common solvents. PBZA could be cured by polymerization of alkynyl groups to form organic–inorganic hybrid structure containing borazine ring and aromatic rings with exothermic polymerization temperature in the 190–250 °C range and the structure exhibits great dependence on the substituent on borazine in PBZA. The cured PBZA exhibits high thermal stability with char yield up to nearly 80% at 1000 °C and great chemical stability. Especially, the cured PBZA shows low dielectric constant (ca. 2.7) and extremely low dielectric loss (<0.002). The cured PBZA under higer annealing temperatures exhibits lower dielectric constant and dielectric loss.

Synthesis and properties of silicon-containing arylacetylene resins with polyhedral oligomeric silsesquioxane

A series of silicon-containing arylacetylene resins containing polyhedral oligomeric silsesquioxane (PS resins) were synthesized by the hydrosilylation reaction between poly(dimethylsilyleneethynylenephenyleneethynylene) (PMSEPE) and octakis(dimethylsiloxy)octasilsesquoixane ( ) in the presence of a platinum catalyst (Pt-dvs). The chemical structures and properties of PS resins were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, rheological analysis, differential scanning calorimetry, dielectric measurement, thermogravimetric analysis, and scanning electron microscopy. The results show that PS resins can be crosslinked to form thermosets at temperatures less than 260°C. With the increment of , the dielectric constants of the thermosets gradually decrease from 2.91 to 2.73. The thermooxidative stabilities of PMSEPE thermosets are obviously improved with the incorporation of . POLYM. ENG. SCI., 55:316–321, 2015. © 2014 Society of Plastics Engineers