A kind of nano-hydroxyapatite/n-maleoylated chitosan composite material and its preparation method and application

Abstract

The invention provides a nano-hydroxyapatite / N-malely chitosan composite material, a preparation method and application thereof. The preparation method comprises the following steps of: firstly, taking oyster shell powder as a raw material, and carrying out hydrothermal reaction with sodium pyrophosphate to generate nano-hydroxyapatite; and then, carrying out acid-base complexing, alkali precipitation and vacuum freeze drying on the nano-hydroxyapatite and N-malely chitosan by a solution blending method so as to obtain the nano-hydroxyapatite / N-malely chitosan composite material. The compositematerial is used as a carrier to be subjected to ion exchange with palladium to prepare an efficient heterogeneous metal palladium catalyst, the catalyst is efficient in catalytic effect, low in price and capable of being repeatedly used, and meanwhile high-valued utilization of marine product waste is promoted.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a nano-hydroxyapatite / N-maleoylated chitosan composite material and a preparation method and application thereof. Background technique [0002] Synthetic chemistry provides a solid material foundation for the development of today's society and the improvement of people's living standards. The discovery and development of new catalysts plays a vital role in synthetic chemistry. The 2010 Nobel Prize in Chemistry was awarded to Suzuki, Nigishi and Heck for their outstanding research in the field of palladium-catalyzed cross-coupling reactions, fully demonstrating the important position of palladium metal in the field of catalytic synthesis. Palladium catalysts have four valence states of Pd(0), Pd(II), Pd(III) and Pd(IV) that are easily transformed into each other, and the phosphine ligands, nitrogen ligands, nitrogen heterocyclic carbene ligands, etc. body, etc., so tha...

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Problems solved by technology

[0003] However, the cost and efficiency of homogeneous palladium catalysis have always been the main bottleneck restricting its application.

Although traditional supported palladium catalysts have the advantage of being able to be recycled and reused, these methods also have many disadvantages: (1) other supports need to be used for functional modification during synthesis, which makes the characterization of the catalyst more difficult, Also improved preparation cost simultaneously; (2) connecting usually can reduce the degree of freedom of catalytic active center and the contact rate with substrate by chemical bond, so the catalytic activity and the selectivity of supporting palladium catalyst than homogeneous catalyst often have in most cases. (3) affected by the solvent, the swelling of the carrier and a series of side effects caused by it, after the catalyst is deactivated, the carrier is difficult to recycle and reuse; (4) the catalyst preparation method is difficult to repeat

At present, the processing of oyster seafood is basically limited to its edible meat part, and there is little processing for other parts. It is mainly disposed of as solid waste in landfill or reclamation. The organic matter remaining in these discarded oyster shells In the process of long-term stacking, corruption and odor will cause serious pollution to the environment

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