by Mad Czech
HC plastic mesh News: 1, Introduction
Alkyd resin is a polyol, multiple acid and acid condensation made a dollar a linear resin, with the synthesis of mature technology, manufacturing process is simple and easy to get raw materials and the resin coating and good overall performance characteristics of coatings used in the synthesis of resin, the largest and most widely used dosage. According to statistics reported in 1997, the National Paint 135 total tons, of which about 350,000 tons alkyd paint, accounting for 52.9% of synthetic resin; United Kingdom, the United States and other developed countries accounted for 30% to 40%, the highest synthesis resin first. However, alkyd paint also has some shortcomings, such as the film is slow drying, low hardness, poor water resistance, which will lead to extended construction period, but also affect its application. To solve the above problems, an integrated domestic and international aspects of the modified alkyd resins reported in the literature, this article through several different methods of chemical modification of alkyd resins were compared to study the mechanism of styrene-modified alkyd resin, the same time, the foundation Synthesis of alkyd resins and alkyd resins both were optimized. The results will be fast-drying alkyd resin to provide theoretical guidance for industrial production and a strong reference.
2, styrene modified alkyd resin chemistry and mechanism of the Methods
Traditional unsaturated oil (fatty acid) modified alkyd resin molecules with hydroxyl, carboxyl, double bond, ester and other reactive groups, therefore, can be chemically synthesized by means of the introduction of other active groups, so that broad chemical modification of alkyd base Jinchu chemical modification can be divided into the following categories: such as Modifier From the carboxyl function, the role of modifier and the use of the double bond from the reaction of hydroxyl chemical modification. Especially the use of chemical modification of the double bond most important chemical modification reaction, in which the most typical modified styrene, copolymerization mainly two kinds of law and pre-polymer.
2.1, copolymerization Vinyl monomer modified alkyd resin often used copolymerization. In accordance with the law of styrene copolymerization time and join in different ways, can be divided into before and after styrene of styrene of two methods.
2.1.1, the former method of styrene
Method includes pre-styrene styrene method of vegetable oils, fatty acids of styrene-based method and the method of styrene monoglyceride of three. Several methods of the above process Styrene points are as follows.
(1) vegetable oil styrene method Process of the law points are: First, styrene monomer and oil in the presence of initiator the reaction of copolymer oil this homogeneous product, the product can be prepared directly instead of vegetable oil alkyd resin. Styrene-based vegetable oil, first glycerol (pentaerythritol or other polyols) alcohol solution generation fatty acid monoglyceride and then phthalic anhydride and other multi-acid esterification.
(2) fatty acid method of styrene
Process of the law points are: first styrene and the initiator dropping into the acid containing DCO reactor, the reaction of styrene for fatty acid, and then vacuum distillation to remove the remaining styrene, further reaction cauldron by adding glycerin and other polyols in the alcohol under inert gas protection solution, and finally into the composition the amount of acid anhydride and other multi-esterification.
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