Properties of Organic Silicone Resin

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Organic silicone resin’s basic structural unit (or the main chain) is constructed by Si-O chains, the side chain is made of the links between silicon atoms and other kinds of organic functional groups and it is highly crosslinked with weave shape polysiloxane. Therefore, organic silicone resin’s structure has not only “organic functional groups” but only contains “inorganic structure”.      This type of special match and molecular structure make it has the properties of organic matter and functions of inorganic matters. To compare with general organic resins, it has the advantages of excellent cold and heat resistance, weather resistance, electrical isolation, odor resistance, hard to be inflame, non-poisoned, biological inertia and chemical resistance. Some special types also have oil resistance, solvent resistance and radiation resistance. Organic resin modified silicone resin is made of polysiloxane and organic polymer. It does not only contain the properties of pure silicone rubber, but it also contains the properties granted by organic resins. Even though the properties above are reduced to compare with pure silicone resins, however, it has stronger properties better than solidification, adhesion, solvent resistance and compatibility. Also, the property of modified silicone resin could also be adjusted by the types of used silicochloroethanes, the types of organic polymers, the contain amount and the types of modification methods. To compare with other macromolecular materials, the most outstanding property of organic silicone product is the excellent temperature resistance, weather resistance and low surface tensile strength.

Relationship between Components of Silicone Resin and Its Properties

The typical types of condensation silicone resin, it is mostly made from the condensation on MeSiX3, Me2SiX2, MePhSiX2, PhSiX3, Ph2SiX3 and SiX4 (X is Cl, OMe or OEt). The proper R/Si and phenyl contain quantity are determined by the usages of resins, the monomers and the corresponding matches are also replied on the properties and usages. For example, MeSiO1.5 chain could award silicone resin the properties of hard, crispy and fast solidification. Me2SiO could grant silicone resin the property of soft and bending. PhSiO1.5 could grant silicone resin hard and average solidification speed. Ph2SiO could grant silicone resin the properties of toughness and slow solidification. These are providing important molecular designs for different methyl phenyl silicone resin’s molecular designs which have different properties.

The methyl phenyl silicone resin’s property is mainly determined by the ratio of number of organic functional groups which are linked to silicon atoms and the quantity of silicon atoms and the ratio of methyl and phenyl. These are the main indicators of controlling the quality of silicone resins. The dry, hardness of coating film and softness of organic silicone resins are all related to R/Si ratio. Generally speaking, methyl phenyl silicone resins are selectively made of MeSiO1.5, Me2SiO, MePhSiO, PhSiO1.5 and Ph2SiO. When R/Si=1, it means each silicon atom only links one organic functional group averagely.

Also, the types of organic functional group R on the silicon atom of silicone resin and the functional group’s ratio of methyl and phenyl could also affect much on the properties of silicone resins; different organic functional group could award silicone resin with properties: When R is methyl, it could award silicone resin thermal stability and demoulding; when R is phenyl, it will award the silicone resin oxidative stability, and it could breaks the crystallinity of macromolecular matters in some certain range; The lower the phenyl percentage in organic functional group is, the manufactured coating film is softer and condensation faster; the percentage is higher, the produced coating film is harder and it will have more thermal plasticity. Also, to lead phenyl could increase the compatibility between silicone resins and pigments; it could also improve silicone resin and other organic silicone resins’ compatibility and silicone resins’ adhesions to all kinds of base materials. Thus, it is possible to lead different numbers and different types of organic functional groups according to the usages on the properties of products: When the organic functional group is vinyl, it could improve silicone resin’s solidification feature and award itself coupling property; when the functional group is tetraoxyphenyl, it could improve polymer’s lubricity; when organic functional group is phenylethyl, it could improve the compatibility between silicone resin and organic matters; when the organic functional group is aminopropyl, it could improve the solubility of polymer into water and grant itself coupling property; when R is amyl it could improves the hydrophobic of silicone resin.

The typical functional groups brought by silicone resins are methyl and phenyl, the ration of methyl and phenyl in organic functional groups have bigger influence in the properties of silicone resins. The less phenyl is, the condensation reaction is faster and the formed coating film is softer; the more phenyl is, the formed coating film is harder and the thermal plasticity is bigger.

Therefore, when manufacturing different types or usages silicone resins, it is the first to think about what monomers are to be used how to lead different organic functional groups into silicon atoms and the ratio of them.

To use MeSiCl3, Me2SiCl2, PhSiCl, Ph2SiCl2 these four types of basic monomers to be the raw materials, is the most common method to produce thermal solidificated methyl phenyl silicone resins. In the condensation reaction processes there are two methods; the condensation between molecules and the condensation in the molecules. Only the one reacted between molecules could increase mol mass. It is during the artifacts of manufacturing silicone resins, the key point is to control the ratio of the condensations occurred between molecules and in molecules.

Summary

From these descriptions, we could see that there are many ways to control the quality of silicone resins and there are also many methods to modify the properties silicone resins have. These methods allow the people to use different ways to design the proper silicone resins which could be applied in their industries to fulfill their goals perfectly. Also, this brings such a huge commercial potential value to silicone resins to make it to be on hot sale in both of domestic and global markets.