1、Improving ablation‐resistant properties of novolac epoxy coatings via
In our preliminary study, we introduced expandable graphite (EG) modified by a coupling agent and boric acid into epoxy-based thermal protection coatings.
2、An addition
In this work, an addition-curable hybrid phenolic resin containing silicon and boron was synthesized via the addition-condensation reaction between 4-hydroxyphenylboronic acid and formaldehyde to obtain boron hybrid novolac resin (BN), which was followed by esterification with vinyltrimethoxysilane.
3、Improving ablation
Improving ablation-resistant properties of novolac epoxy coatings via boric acid or POSS-modified expandable graphite with a PDA bridge - 科研通
4、Improving ablation
Improving ablation-resistant properties of novolac epoxy coatings via boric acid or POSS-modified expandable graphite with a PDA bridge
5、Fabrication and characterization of microfluidic devices based
CO 2 laser ablation is a rapid and precise technique for machining microfluidic devices. And also, low-cost epoxy resin (ER) proved the great feasibility of fabricating these devices using the CO...
Research Progress in Boron
In this review, the current state of development of BPF and its composites is presented and discussed. After introducing various methods to synthesize BPF, functionalization of BPF is briefly summarized.
Structural evolution during the catalytic graphitization of a
The structural evolution that occurs when catalyzed novolac resin containing boron oxide or boric acid was subjected to thermal treatment was studied using FTIR technique.
Improving ablation
Expandable graphite (EG) was modified by some coupling agents and boric acid to increase the interaction force between inorganic fillers and epoxy resin phases. A novel epoxy-based...
SYNTHESIS AND CHEMICAL MODIFICATINON OF NOVOLAC VIA INCORPORATION OF
The esterification7 of phenol novolac resins with inorganic polybasic acids such as phosphoric and boric acid or the reaction with phosphorus oxyhalides are a particular important in increasing the heat or flame resistance of phenolic resins, because of the high OH–functionality of novolacs.
Improving ablation
In our preliminary study, we introduced expandable graphite (EG) modified by a coupling agent and boric acid into epoxy-based thermal protection coatings.
In the vast realm of chemistry, novolac resin has long attracted attention due to its unique properties and widespread applications. with advancements in technology and growing demands for novel materials, traditional novolac resin has gradually revealed its limitations. Scientists have thus explored doping it with boric acid to enhance its performance, aiming to unlock greater application potential.
Novolac resin, also known as phenolic resin, is a thermosetting polymer formed by the reaction of phenolic compounds with aldehydes. It boasts excellent mechanical strength, electrical insulation, and corrosion resistance, making it widely used in electronics, automotive, construction, and other fields. it suffers from drawbacks such as low heat resistance and poor moisture resistance, which limit its use in harsher environments.
To address these limitations, researchers have introduced boric acid into novolac resin to improve its properties. Boric acid, a strong-base-weak-acid salt, exhibits high chemical and thermal stability. This enables it to react with phenolic and aldehyde groups in the resin, forming stable covalent bonds. Additionally, boric acid enhances the resin’s heat and moisture resistance, allowing it to maintain stability across broader temperature and humidity ranges.
Specifically, when boric acid is doped into novolac resin, it reacts with phenolic hydroxyl and aldehyde groups, forming boronate ester groups. These groups stabilize the resin at high temperatures, reducing degradation or flammability. Furthermore, they interact with other functional groups in the resin, creating a denser crosslinking network that improves mechanical strength and thermal resilience.
Boric acid also boosts moisture resistance. By reacting with water molecules in the resin to form borates, it lowers the material’s water absorption rate. This enables the resin to retain its performance in humid environments, preventing moisture-induced degradation or damage.
Beyond heat and moisture resistance, boric acid doping may introduce additional benefits. For instance, boric acid could interact with other functional groups, altering the resin’s chemical structure and potentially endowing it with new properties, such as higher electrical conductivity or improved optical characteristics.
doping boric acid poses challenges. The concentration and incorporation method must be precisely controlled to avoid compromising other properties. post-doping processing may be required to fully realize the resin’s potential. Practical applications thus demand careful consideration of various factors to optimize doping strategies.
boric acid-doped novolac resin represents a promising avenue for performance enhancement. While research remains in early stages, this field opens new possibilities for advanced materials. With further study and technological maturation, boric acid-modified novolac resin is poised to play a larger role in future scientific and industrial progress.
