Synthesis and properties of acetylene-containing cross-linkable triazine resin

Study on vinyl crosslinking and related properties of silicon-containing arylacetylene resin synthesised by zinc powder catalysis

A matrix resin poly(silicon-containing arylacetylene vinyl)s (PSAV) containing vinyl at both branch and terminal chains underwent synthesis via the zinc powder catalytic method using m-diacetylene benzene and dichloromethylvinylsilane as raw materials. Vinyl in the PSAV resin was crosslinked by the free radical initiator dibenzoyl peroxide to obtain a crosslinked network structure resin (PSAV-L). This approach sought to improve the thermal properties and other related properties of the matrix resin. A series of tests, such as rotated rheometer, FTIR, DSC, TGA, Py-GC-MS and universal testing machine, characterised processing property, curing behaviour, thermal properties and mechanical properties. The rheological curve shows that PSAV-L resin has a wide processing window (40–134.5°C), endowing the resin with excellent processing performance. Thermal curing behaviour indicates that PSAV-L resin can start curing at a lower temperature, namely, 32°C earlier than PSAV resin. TGA analysis shows that the degradation temperature at 5% weight loss (Td5) of PSAV-L resin stands at 579.4°C, 45.4°C higher than that of PSAV resin due to the fact that the crosslinking of vinyl gives PSAV-L resin a network structure. The flexural strength, flexural modulus and ILSS of the quartz fibre cloth reinforced PSAV-L resin composite (QF/PSAV-L) are 184.68 MPa, 15.50 GPa and 12.40 MPa. The PSAV-L resin exhibits the comprehensive properties of good processing performance, low curing temperature, excellent thermal performance and high mechanical properties.

Study on the anhydrous condensation of collagen polypeptide and tricyanogen chloride

The molecular weight of collagen-degrading polypeptides (CDPs) extracted using the alkali method from leather scraps must be expanded to improve its utilization effect.

SiBCN ceramic precursor modified phthalonitrile resin with high thermal resistance

In order to expand the application of phenolic-type phthalonitrile resin in high-temperature fields, a series of organic–inorganic hybrid materials have been prepared via conventional blending and doping method. The chemical transformations were monitored by various measurements, while the curing behavior was evaluated by differential scanning calorimetry (DSC), and these new blends could be also cured under auto-catalytic process. The onset polymerization exothermic temperature shifted to lower temperatures (195.3°C). Later, the compatibility within the cured products was analyzed by using energy dispersive spectrometer (EDS) and scanning electron microscope (SEM), where no phase separation occurred between the ceramic domain and the phthalonitrile polymer. Upon curing, the thermal properties of the polymers were characterized by dynamic thermomechanical analysis (DMA) and thermogravimetric analysis (TGA), where enhanced heat resistance and thermal stability were discovered, The blends residual weight (Cy) value was 57.6% with 15 wt.% SiBCN at 1000°C. And when blended with SiBCN precursor, no peak or onset point could be observed in the temperature range (50 to 500°C), which indicated the glass transition temperature greater than 500°C. Additionally, the dielectric properties were evaluated. And when the content was 5 wt.%, the blends dielectric loss was 0.0043 and the permittivity was 4.31. The above results indicated that the introduction of ceramic precursors could enhance the thermal performance of phthalonitrile polymers, consequently the hybrid materials shown great potential in the application of higher temperature fields.