Research On The Solid State Reaction At Low Temperature By Superfine Airflow

Superfine airflow grinding technology is one of the common means forpreparation of ultrafine powder, which has been widely used in the foods,pharmaceuticals, chemical and nonmetallic minerals, etc. However, with respect to itsapplication fields, the applied of this technique is mostly limited to the pure physicalcrushing process, relatively small study on synthetic chemistry, especially synthesis ofmetal organic complexes. In this paper, ultrafine airflow grinding technology iscombined with solid reaction at low temperature, and several metal organiccomplexes and organic compounds are synthesized successfully. The main results inthis paper are as follows:(1) Two copper (II) complexes with m-, p-aminobenzoic(m-AB, p-AB) acidderived from cupric acetate monohydrate and m-AB and p-AB was prepared by solidstate reaction at low temperature under ultrafine airflow. The molecular structure[Cu(m-NH2C6H4COO)2] and [Cu(p-NH2C6H4COO)2] were determined by a series ofcharacterization methods, and non-coordinated water molecules exist in bothcomplexes. Meanwhile, monodentate and bidentate bridging type of coordination withcarboxylate group in copper(II) m-AB and copper(II) p-AB, respectively. Besides,compared with liquid phase method and grinding in terms of reaction time, yield andthe composition, structure of products, the complexes from solid state reaction at lowtemperature under ultrafine airflow have no difference in which synthesis from liquidphase and grinding. The yields were89.82%and88.26%for copper(II) m-AB andcopper(II) p-AB, respectively. This is very close to grinding, but significantly betterthan liquid phase.(2) The Co(II)-Hexmethylenetetramine[Co(II)-HMTA] complex was synthesizedthrough the same method derived from HMTA and CoCl2·6H2O. The characterizationresults showed that the complex contained6coordinated water molecules, which hasa similar structure with the product of liquid phase. The isothermal crystallizationbehavior of Co(II)-HMTA complex/PLLA(LG/PLLA) was investigated in detail. Theresults showed that complex Co(II)-HMTA could shorten the semi-crystalliztion timeand increased cristillization of poly(PLLA), this indicated that the Co(II)-HMTAcomplex can play a nucleating effect on PLLA. When the content of Co(II)-HMTAcontent was about2%, compared to pure PLLA, the crystallization half time from 96.52min to3.85min.(3) Two shiff bases which derived from p-chlorobenzaldehyde andp-aminobenzoic acid, o-nitrobenzaldehyde and p-aminobenzoic acid were prepared bysolid state reaction at low temperature under ultrafine airflow. The geomistrystructures have been optimized through semiempirical method PM3and the frontierorbital energies were obtained. It explained why the synthesis of shiff base derivedfrom o-nitrobenzaldehyde and p-aminobenzoic acid was easilier than shiff basederived from p-chlorobenzaldehyde and p-aminobenzoic acid in theory.(4) Theroretical analysis showed that the reaction temperature, reactatant particlesize and whether it contains water of crystallization have a great influence on solidstate reation under ultrafine airflow, and self-friction and self-diffusion of particleswere the rate-determining step during the reation.