2018年7月9日星期一

For the preparation of Coatings?The role of TRIS you may not know!

As we all know, Tris(Hydroxymethyl)Aminomethane (TRIS) is not only widely used as a buffer for biological and chemical experiments, but also as solvent for nucleic acids and proteins, intermediates of surfactants, pesticide and drugs. But today, we will introduce the application of TRIS you may not know——For the preparation of Coatings.


TRIS (THAM) plays four main roles in the preparation of the coating: pH regulator, crosslinking accelerators, polyester coating materials and phase change cores.

1. pH Regulator

The effective buffering range of TRIS buffer is pH 7.0~9.2. Yuan et al. [1] invented a non-yellowing polyester coating with best pH value of 7.5~8.5 in the preparation. Researchers used TRIS buffer to adjust the pH value. The prepared product had good adhesion and scratch resistance, and it will not significantly yellowed after high temperature operation or aging.

2. Crosslinking Accelerator

Crosslinking accelerators can act as bridging molecules between linear molecules, so that multiple linear molecules are bonded to each other to form a network structure. Polyhydric alcohols are often used as external crosslinks in the preparation of coatings. Zhang Jianwei et al. [2] invented a silane modified polyurethane glass coating with TRIS as a cross-linking promoter. Which can be operated in the air at room temperature for 40min without obvious thickening phenomenon.

3. Polyester Coating Materials

Polyhydric alcohols, polyacids, catalysts and antioxidants can be used as a coating composition. Deng Mujian et al. [3] used TRIS as the polyhydric alcohols to react with the polybasic acid or anhydride terephthalic acid or isophthalic acid, to obtain an outdoor dry blending powder coating polyester resin.


4. Phase Transition Core

When the temperature reaches the phase transition temperature, the structure of the polyol phase transition material will change from the layered body-centered structure to the isotropic facial-centered structure, and the hydrogen bonds between the layers are broken, molecules change from crystalline to amorphous, and release bond energy. It has the advantage of large enthalpy of phase change, stable performance, long service life. Gao Hongyi et al. [4] used the polyol characteristics of TRIS as a phase change core to prepare an airgel based phase transition coating.

TRIS (CAS 77-86-1) is not only an important biological buffer, but also an important material for organic synthesis. Although the application in the field of coatings is not very extensive, but with the development of science and technology, we believe that TRIS will get more applications in this area in the future.

References

[1] San C. Yuan, Mitchell S. Chinn. Non-yellowing polyester coating composition. US 7,087,672 B2, August 8, 2006.
[2] Zhang Jianwei, Du Houjun, Wang Yudong, et al. Silane modified polyurethane glass primer and preparation method. CN 102516921 B, 2013, 10, 02.
[3] Deng Mujian, Zhang Liangfu, Cao Yongyi, and so on. Preparation of polyester resin for outdoor dry blending powder coating. CN 102719180, 2012, 10, 10.
[4] Gao Hongyi, Feng Yanhui, Zhou Xiaofei. A preparation method of air-gel-based thermal phase transition coating. CN 105199472, 2015, 12, 30.


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