Novolac resin (NR) modified with 1, 1’-bis(dimethylsilyl) ferrocene (FeNR) was synthesized. The thermal properties and structural evolution of cured FeNR were studied to analyze the reason for high char yield of cured FeNR. Thermal stability of cured FeNR has been improved, and the char yield of cured FeNR at 800 °C can be increased by 8.82% in comparison to that of cured NR. The results show that silicon atom and ferrocene contribute to the high char yield of cured FeNR. On one hand, the Si-O structure can be kept in the system during the whole pyrolysis process, which could help to reduce the weight loss. On the other hand, introducing ferrocene into novolac resin promotes the graphitization degree and graphite crystallites of pyrolyzed resins. Moreover, the pyrolyzed products possess different magnetic properties owing to the formation of iron nanocrystal at 800 °C and Fe5Si3 nanocrystal at 1200 °C.

4-hydroxymethyl phenylboronic acid (4-HMPBA), phenol and formaldehyde were for the first time to synthesize boron containing novolac phenolic resins (Novolac-4-HMPBA). Its corresponding carbon fibers (CF) composites were also fabricated via the lamination followed by hot-compression. Results revealed that Novolac-4-HMPBA was successfully synthesized. Compared to common novolac phenolic resin (NPR), the corresponding decomposition temperature of 5% weight loss (T5) and char yield at 800 °C (C800) of cured Novolac-4-HMPBA-30 were increased to 369.1 °C and 69.7%, increased by 41.3% and 26.3%, respectively. The CF/Novolac-4-HMPBA-20 composites presented relatively higher interlaminar shear strength (ILSS) of 35.9 MPa, increased by 50.2% compared to that of CF/NPR composites. After the treatment at 800 °C for one hour under Ar atmosphere, the corresponding ILSS value of CF/Novolac-4-HMPBA-20 composite was decreased to 7.8 MPa, but still higher than that of CF/NPR composites (3.0 MPa).

•SiBCN ceramic coating is prepared successfully.•Single source precursor is used as the starting material.•The coating is prepared along PDCs route.•UV-photopolymerization is used to cure or solidify the precursor.•The fast UV-curing ensures the formation of coating on different substrates.Polymer derived SiBCN ceramics (PDCs) exhibit many excellent properties such as high-temperature stability and oxygen resistance. In this work, the SiBCN-containing UV-curable single source precursor a-TSEB was used as the starting material to prepare ceramic coating. The ceramic coating was prepared via spin coating, UV-polymerization and pyrolysis. The viscosity of the precursor was tested which is fluctuated around 57.75 mPa·s, means that the viscosity is low enough to coat on the surface of substrate. SEM micrographs showed that the compacted coatings are formed without any penetrating cracks or holes on samples and the interface bonding performance is good.

Phenol, zinc acetate dihydrate and paraformaldehyde are firstly performed to synthesize thermoplastic phenolic resin (PR), then phenylboronic acid (PBA) and other two boron compounds (4-hydroxymethyl phenylboronic acid & boronic acid) are introduced to fabricate the boron-containing thermoplastic phenolic resins (BPRs). The corresponding molecular structure, softening points, thermal decomposition temperature and char yield ratio of the BPRs are characterized and investigated by FTIR, NMR, XPS and TGA. Compared to pure thermoplastic PR, all the BPRs present relatively higher softening points, more excellent thermal decomposition temperature and higher char yield values. BPR-a exhibits the optimal thermal decomposition temperature (T5 of 317.4 °C) and char yield ratio at 800 °C (69.6 %).

SiBCN ceramic precursor, polyborosilazane, was synthesized through a novel method which used sodium borohydride as boron source. Vinyl silazane with SiCl was converted to vinyl silazane with SiH structure, followed by hydroboration reaction and subsequent high-temperature reaction to form soluble polyborosilazane liquid. The process of precursor-to-ceramic conversion was almost completed before 800 °C and the cross-linked polyborosilazane precursor exhibited higher ceramic yield 75.6% at 1200 °C. The SiBCN ceramic annealed at 1400 °C contained BN, SiN and SiC bonds with smooth and dense surface and still retained principally amorphous structure up to 1600 °C. In addition, the viscosity of the polyborosilazane was 65 mPa.s, which can efficiently prepare ceramic matrix composite by means of precursor infiltration and pyrolysis (PIP). The density of as-obtained ceramic matrix composite (CMC) was 1.82 g/cm3, and the average bending strength, bending modulus and tensile strength were 265.2 MPa, 37.5 GPa and 158.6 MPa, respectively.