一区国产传媒国产精品,国产精品精品自在线看,高清v欧美v亚洲v精品,久久综合伊人大杳蕉色秀

Epoxy resin refers to a polymer compound containing two or more epoxy groups in its molecules. Due to its excellent physical and mechanical properties, electrical insulation, adhesive properties with various materials, and flexibility in use, it has gradually become an important thermosetting resin, mainly used in industries such as construction, automobiles, equipment and instruments. According to molecular structure, epoxy resins can be divided into five major categories: glycidyl ethers, glycidyl esters, glycidyl amines, linear aliphatic groups, and alicyclic groups. In the composite material industry, the most commonly used type is glycidyl ether epoxy resin, which is mainly formed by the condensation of phenols or alcohols containing active hydrogen with epichlorohydrin (ECH). Among them, bisphenol propane epoxy resin, also known as BADGE, accounts for about 70% to 80% of the total consumption of epoxy resin (about 95% in China). The industrial production methods of BADGE mainly include one-step and two-step methods, and other synthesis methods include solid alkali method, solvent method, atmospheric and vacuum azeotropic method, phenolic salt method, etc. Although bisphenol A epoxy resin has been successfully industrialized for nearly 70 years, due to fierce market competition and technological confidentiality, there have been few reports on its synthesis technology research papers and patents in the past 20 years. There are still many problems in the synthesis of bisphenol A epoxy resin in industry. Therefore, this article elaborates in detail on the synthesis mechanism, industrial production methods, and research progress of BADGE.

Polyimide resin is a high-performance structural material with the following advantages: high strength and toughness: Polyimide resin has high strength and toughness, can withstand heavy pressure, impact, and other external pressures, and is suitable for various application scenarios. High temperature and acid alkali corrosion resistance: Polyimide resin has excellent heat resistance and acid alkali resistance, and can adapt to high temperature and acid alkali environments.

Epoxy resin reinforcement adhesive is a high-performance building structural adhesive used for repairing and strengthening concrete structures. It is mainly composed of epoxy resin, fillers, and hardeners, with extremely high bonding strength and compressive strength. The use of epoxy resin reinforcement adhesive has become an important technology in modern construction, which can effectively improve the structural strength and durability of buildings.

People have been committed to improving the fracture toughness of epoxy resins by introducing various types of additives, including rubber and rigid particles. This method faces challenges related to poor dispersion and other performance degradation, such as a decrease in elastic modulus and glass transition temperature. On the other hand, block copolymer modifiers have been shown to increase strain energy release (GIc) by 20 times at relatively low concentrations (<5wt%).

In modern polymer materials such as plastics, rubber, and coatings, non-metallic mineral fillers (such as calcium carbonate, talc powder, magnesium oxide, titanium dioxide, etc.) play a very important role. Adding non-metallic mineral fillers to polymer based materials can not only reduce the cost of polymer materials, but more importantly, improve the performance and dimensional stability of the materials, and endow them with special physical and chemical properties, such as weight reduction, compression resistance, impact resistance, scratch resistance, corrosion resistance, flame retardancy, insulation, etc.

After absorbing a certain wavelength of light energy, photoresist should undergo photochemical reactions, causing cross-linking or degradation of polymers, which can lead to changes in polymer solubility. Becoming insoluble or soluble in solvent, the photoresist is coated onto the base material based on this characteristic to make a pre coated photosensitive plate.