Guangzhou Longkai Chemical Co., Ltd.
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Instructions for the Use of Silane Coupling Agents and Principles for the Application of Silane Coupling Agents in Chemical Industry
Author:LongKom  Time:2017-12-16

When silane coupling agent is used as tackifier, it is mainly realized by forming chemical bond and hydrogen bond with polymer, wetting and surface energy effect, improving polymer crystallinity, acid-base reaction and formation of interpenetrating polymer network with titanate coupling agent. Viscosity enhancement mainly revolves around three systems: inorganic material to organic material; inorganic material to inorganic material; organic material to organic material. For the first kind of bonding, inorganic materials are usually required to be bonded to polymers, so the reactivity of Y in silane coupling agent with functional groups in polymers should be given priority; the latter two belong to the bonding between the same types of materials, so the anti-hydrophilic polymer of silane coupling agent itself and the silane coupling agent selected when inorganic materials require tackifying.

The selection of organosilane coupling agents is usually based on the face summary of the side test data of organosilane coupling agents. It is very difficult to predict organosilane coupling agents accurately. The increased bond strength of silane coupling agent is a combination of a series of complex factors, such as infiltration, surface energy, boundary layer adsorption, polar adsorption, acid-base interaction and so on.

Pre-selected organosilane coupling agent can follow the following rules: ethylene compilation, epoxy group and methyl propylene aging oxy type organosilane coupling agent can be selected for unsaturated polyvinegar; epoxy resin should be selected as epoxy or amino type organosilane coupling agent; phenolic resin should be selected as amino or serving type organosilane coupling agent; olefin polymer should be selected as vinyl type right organosilane coupling agent; If the minimum tax area and specific surface area of organic silane coupling agent are not clear, the base material, i.e. filler, should be treated with organic value alkane coupling agent of 1% weight, and then the concentration of alkane coupling agent should be changed to obtain the appropriate amount by experimental method. The amount of organic brick alkane coupling agent is generally 0.1-2% of the weight of the treated base material or filler.

Understanding the instructions for the use of silane coupling agents

It is known that the hydrolysis rate of silane coupling agent is determined by the silicon group Si-X, while the reactivity with organic polymer is determined by the carbon functional group C-Y. Therefore, it is very important to select suitable silane coupling agents for different substrates or treatment objects. The method of selection is mainly through pre-selection by experiment, and should be based on existing experience or rules. For example, in general, unsaturated polyesters use silane coupling agents containing CH2=CMeCOO, Vi and CH2-CHOCH_2-; epoxy resins mostly use coupling agents containing CH2-CHCH_2O and H_2N-silane; phenolic resins mostly use coupling agents containing H_2N-and H_2NCONH-silane; polyolefins mostly use vinyl silane; rubber vulcanized with sulfur yellow mostly uses alkyl silane and so on. The bonding degree of heterogeneous materials is affected by a series of factors, such as wettability, surface energy, interface layer and polar adsorption, acid-base interaction, interpenetrating network and covalent bond reaction. Therefore, it is not precise to select the material only by experiment, and the composition of the material and its sensitivity to silane coupling agent should be considered comprehensively. In order to improve hydrolysis stability and reduce modification cost, Guangzhou titanate coupling agent can be mixed with trialkyl silane. For refractory materials, silane coupling agent can also be used as cross-linking polymer.

As mentioned above, one of the main applications of silane coupling agents is to treat inorganic fillers used in organic polymers. The latter can transform its hydrophilic surface into a hydrophilic organic surface by silane coupling agent, which can not only avoid the aggregation of particles and the rapid thickening of polymers in the system, but also improve the wettability of organic polymers to reinforcing fillers. Carbon functional silane can also make reinforcing fillers bond firmly with polymers. However, the use effect of silane coupling agent is also related to the type and dosage of silane coupling agent, the characteristics of substrate, the properties of resin or polymer, and the application occasion, methods and conditions. This section focuses on two methods of using silane coupling agent, Guangzhou titanate coupling agent, i. e. surface treatment method and whole blending method. The former is to treat the surface of the matrix with dilute solution of silane coupling agent, while the latter is to add the original solution or solution of silane coupling agent directly into the mixture composed of polymer and filler, so it is especially suitable for the material system requiring mixing.