Hyperdispersant Non woven machinery
日期：2021/3/16 9:10:56 / 閱讀： / 來源：本站
Non woven machineryThe molecular structure of traditional dispersant (surfactant) contains two opposite groups in solubility and polarity, one of which is short polar group, which is called hydrophilic group. Its molecular structure features make it easy to arrange on the material surface or two-phase interface, reduce the interfacial tension, and have good dispersion effect on aqueous dispersion system. However, its molecular structure has some limitations: hydrophilic groups are not firmly combined on the surface of low polar or non-polar particles, which is easy to desorb and lead to the re flocculation of the dispersed ions; lipophilic groups do not have enough carbon chain length (generally no more than 18 carbon atoms), which can not produce enough steric hindrance effect in the non-aqueous dispersion system to play a stabilizing role. In order to overcome the limitation of traditional dispersant in non-aqueous dispersion system, a new type of super dispersant was developed, which has a unique dispersion effect on non-aqueous system. Its main characteristics are: wetting particles quickly and fully, shortening the grinding time to reach the qualified particle size; greatly increasing the solid particle content in the grinding base material, saving processing equipment and energy consumption; The dispersion is uniform and the stability is good, so that the end use performance of the dispersion system is significantly improved.
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The molecular structure of the super dispersant is divided into two parts: one is the anchoring group, and the common ones are - R2N, - RN +, - COOH, - COO -, - so: H, - so -, - Po, polyamines, polyols and polyethers. They can be tightly adsorbed on the surface of solid particles through the interaction of ionic bond, covalent bond, hydrogen bond and van der Waals force to prevent chain reaction. In the dispersion medium with matching polarity, the solvation chain has good compatibility with the dispersion medium. The solubility in the dispersion medium can be divided into three types: low polarity polyolefin chain; medium polarity polyester chain or polyacrylate chain; strong polarity polyether super dispersant desorption; high polarity polyether super dispersant desorption; The other part is solvated chain, such as polyester, polyether, polyolefin and polyacrylate. According to the relatively extended conformation, a protective layer with enough thickness is formed on the surface of solid particles. Non woven machinery www.www.dressup9x.com
The mechanism of Hyperdispersant includes anchoring mechanism and solvation mechanism. "Single point anchorage". Non woven machinery www.www.dressup9x.com
For organic particles with weak polar surface, such as organic pigments and some inorganic pigments, it is usually a super dispersant with multiple anchoring groups, which can form "multi-point anchoring" on the particle surface through couple force. No matter what kind of super dispersant is used, the dispersion effect is not obvious. This is a kind of pigment derivative with polar group. Its molecular structure and physicochemical properties are very similar to those of disperse pigment. It can be tightly adsorbed on the surface of organic pigment through intermolecular van der Waals force. At the same time, the polar group of its molecular structure can provide the degree of adsorption for anchoring group of super dispersant The super dispersant can effectively wet and stabilize organic pigments.
Solvation mechanism: the other part of the super dispersant is solvation polymerization chain, and the length of the polymerization chain is an important factor affecting the dispersion performance of the super dispersant. If the length of the polymer chain is too short, the stereoscopic effect is not obvious, and enough steric hindrance cannot be produced; If it is too long, it will have too high affinity for the medium, which will not only lead to the desorption of the super dispersant from the particle surface, but also cause the unfolding of the long chain on the particle surface, which will compress the steric hindrance or cause entanglement with adjacent molecules, and finally lead to the re aggregation or flocculation of particles.