Aqueous PES Dispersion And Redispersible PES Powder Preparation

The microencapsulation of pharmaceutical compounds with PLAor PLGA by the solvent evaporation method bas been investigatedextensively during the past 25 years. More recently, biodegradablemicroparticles have also been prepared by spray-drying and bysupercritical fluid technology .We use solvent evaporation method toprepare the aqueous polymer ether sulfone dispersion and then drythese dispersion by spay drying method to prepare PES redispersiblepowers than redisperse to prepare the high solid aqueous PESdispersions. The objective of this study was to investigate the effect ofthe addition surfactant and solvent during preparing the aqueousstability PES dispersion by solvent evaporation and redispersible PESpowders by spray drying. In the solvent evaporation process, the polymer of PES isdissolved in a suitable water immiscible solvent, Chloroform, andsurfactant dissolved in water. The resultant solution or dispersion isthen emulsified in an aqueous continuous phase to form discretedroplets. In order for the PES dispersions (non- organic solvent) toform, the organic solvent (Chloroform) must first diffuse into theaqueous phase and the evaporation at the water/air into face. As solventevaporation occurs, the PES microspheres harden and free flowingmicrospheres can be obtained after suitable spray drying. 52吉林大学硕士学位论文 This paper discuss that the aqueous PES dispersions stability,particle distribution, PES powders of redispersion. We draw a conclusion from the experiment: Pass to choose, DBS (Dodecyl benzene sulfonic acid sodiumsalt) and PVP (polyvinypyvvolidone K30) are equal to acting surfacetant prepared aqueous PES dispersions Chloroform and methanol as solvent are equal to preparing the aqueous PES dispersions because of their boil low than water and reclaiming. The usage DBS and PVP prepare the aqueous stability PES dispersion of average particle diameter bigly than only usage DBS. 10%~20% PES dispersions of average particle diameter range between 50~80nm. The usage DBS and PVP prepare the aqueous PES dispersion that are equal to preparing the redispersible PES powders, but only usage DBS don't equal to. The usage DBS and PVP prepare the PES powders that have regular sphere and not change by spray drying. But only usage DBS prepare the PES powers to change particle's the shape and particle reunite. When usage DBS and PVP prepare the PES powders, PVP form protect film on the particle surface to hold back reunite. But only usage PVP prepare the PES dispersion that don't stability and easy reunite. PES power by usage DBS and PVP can easy renew dispersive 53吉林大学硕士学位论文 into water as milk powder. Therefore preparing redispersible PES powder use complex DBS and PVP, preparing aqueous stability PES dispersion only use DBS. The effectiveness of the solvent evaporation method to produceaqueous PES dispersions depends on the successful entrapment of theactive agent within the particles, and thus, this process is mostsuccessful with PES particles. The amount of the PES in the organic phase was varied from 1%to 15%, and it was found that the mean particle diameter decreasedfrom 192.9nm to 113.5nm, then increase from 113.5nm to 245nmfollowing PES in the organic phase varing from15% to 25%. Aqueous stability PES dispersion can develop PES applicationscope. Redispersible PES powder add to poly tetrafluoroethyleneemulsion preparing preservative coating. Aqueous PES dispersion and Redispersible PES powder haveextensive and applied foreground. 54...