The preparation method of alkyd resin is to condense polyfunctional alcohols, polybasic acids and vegetable oils or vegetable oleic acids. Different types of vegetable oils or fatty acid molecules have different numbers of double bonds, which can be divided into drying, non-drying and Semi-dry alkyd resin. Dry alkyd resin can dry by itself in the air, and its drying is a process in which macromolecules are cross-linked and solidified by oxygen in the air. According to the content of vegetable oil or vegetable oleic acid used, there are short oil, medium oil, long oil, extra long oil and ultra short oil alkyd resin. The manufacturing methods of alkyd resin include melt method and solvent method. The melting method uses polyols, polybasic acids, vegetable oils or vegetable oleic acids to be heated under the protection of inert gas and lipidized at high temperature. When the acid value reaches the required level, solvent is added to dilute it. In the solvent method, the reaction raw mater...

Epoxy resin is a high molecular polymer with the molecular formula (C 11 H 12 O 3 ) n . It refers to a class of polymers containing more than two epoxy groups in the molecule. It is the condensation product of epichlorohydrin and bisphenol A or polyol . Due to the chemical activity of the epoxy group , a variety of compounds containing active hydrogen can be used to open the ring and solidify and cross-link to form a network structure , so it is a thermosetting resin . Bisphenol A-type epoxy resin not only has the largest output and the most complete varieties, but also new modified varieties are still increasing, and the quality is constantly improving.   Physical and chemical properties   material properties   Epoxy resin has secondary hydroxyl groups and epoxy groups , and the secondary hydroxyl groups can react with isocyanates . Epoxy resin is directly added as a polyol to the hydroxyl-containing component of the polyurethane adhesive . Using this method, only the ...

Polymer compounds, referred to as macromolecules, also known as high molecular polymers, generally refer to compounds with a relative molecular mass of several thousand to millions. The vast majority of polymer compounds are mixtures of many homologues with different relative molecular masses , so they are highly The relative molecular mass of a molecular compound is the average relative molecular weight. Polymer compounds are composed of thousands of atoms connected to each other by covalent bonds . Although their relative molecular masses are large, they are all connected in a simple structural unit and in a repetitive manner.   Introduction   The molecules of high molecular compounds are much larger than the molecules of low molecular organic compounds. Generally, the relative molecular mass of organic compounds does not exceed 1000, while the relative molecular mass of polymer compounds can be as high as 10 4 to 10 6 . Due to the large relative molecular mass of polymer ...

Titanium ore refers to minerals containing a large amount of titanium ore. The main ones utilized in China are ilmenite , rutile and titanium magnetite .   Raw material characteristics   Titanium is a typical lithophile element and often appears as an oxide mineral. There are more than 80 kinds of minerals containing more than 1% TiO2 in the earth’s crust, and 15 kinds have industrial value. The main ones used in China are ilmenite , rutile and titanium magnetite (Table 3.5.1). They are both primary (rock minerals) and secondary (weathered residual slope accumulation and sedimentary sand minerals ).   Properties of titanium   Because titanium metal is silvery white, it has a high melting point (1727°C), light specific gravity (4.5), high mechanical strength (5), low temperature resistance (resistivity is almost 0 at ultra-low temperatures), abrasion resistance, and good plasticity of titanium wire (can Thin-walled use), not easily oxidized, and highly reducib...