OVER THE LAST TWO DECADES, NOVEL APPLICATIONS OF MICRO/NANO POLYMER PARTICLES IN DIFFERENT FIELDS HAVE ATTRACTED THE INTEREST OF THE RESEARCH COMMUNITY. IN THIS ARTICLE FIRST SYNTHESIS OF MONODISPERSE POLYSTYRENE (PS) PARTICLES (2.7MM IN DIAMETER) IS PRESENTED, AND THEN THEY ARE USED FOR SEEDED DISPERSION POLYMERIZATION OF 2-ETHYLHEXYL METHACRYLATE IN THE PRESENCE OF N-DECANE, WHICH IS LATER EXTRACTED TO GIVE HOLLOW PARTICLES WITH AN IRREGULAR MORPHOLOGY. POLYMERIZATION AT HIGHER TEMPERATURES RESULTED IN PENETRATION OF SOLVENT INTO THE PARTICLES, LOWER VISCOSITY, ADDITIONAL SOLVENT EXTRACTION CAVITIES CREATED IN PARTICLES, AND HENCE FORMATION OF A VARIETY OF MORPHOLOGIES.

AQUEOUS DISPERSION TERPOLYMERIZATION OF ACRYLONITRILE (AN), ACRYLAMIDE (AAM) AND ITACONIC ACID (IA) WAS CARRIED OUT IN WATER AT 40 °C USING AMMONIUM PERSULPHATE (APS) AND SODIUM BISULFITE (SBS) AS INITIATORS. MONOMERS COMPOSITION IN FEED WERE 97.5/2/0.5 AND 96.5/2.5/1 (AN/AAM/IA). THE POLYMERS WERE CHARACTERIZED BY USING FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR), DIFFERENTIAL SCANNING CALORIMETRY (DSC). THE DILUTE SOLUTION VISCOSITIES OF THESE TERPOLYMERS WERE STUDIED AS A FUNCTION OF MOLECULAR WEIGHT. THE EFFECT OF TWO COMPOSITIONS OF PAN TERPOLYMERS ON THE THERMAL BEHAVIOR AND EFFECT OF VARIATION OF THE CONCENTRATIONS OF REDOX INITIATOR ON THE VISCOSITY AVERAGE MOLECULAR WEIGHTS OF TEROPOLYMERS WERE STUDIED. THE INCORPORATION OF 2.5MOL% AAM AND 1MOL% IA INTO TERPOLYMER SHOWED THE BETTER THERMAL BEHAVIOR FOR CARBON FIBER PRODUCING.

THIS PAPER CONSIDERS THE EFFECT OF TWO PARAMETERS CONTAINS STABILIZER AND INITIATOR CONTENTS ON MORPHOLOGY AND AVERAGE NANOPARTICLES DIAMETER PREPARED BY SEEDED POLYMERIZATION METHOD. EACH PARAMETER WAS CHANGED TWICE AND ITS EFFECT HAVE OBSERVED. THE MORPHOLOGY OF PARTICLES WERE OBSERVED BY SEM MICROSCOPY AND SIZE OF PARTICLES DIAMETER MEASURED BY IMAGEJ SOFTWARE. RESULTS SHOWED THAT INCREASING PVP CONTENT, AVERAGE PARTICLES DIAMETER AND DISPERSION COEFFICIENT HAS DECREASED. ON THE OTHER HAND, IT SEEMS RAISING OF AIBN CONTENT LEADS TO AVERAGE PARTICLES DIAMETER AND DISPERSION COEFFICIENT INCREASING.

THIS PAPER CONSIDERS THE EFFECT OF POLYMERIZATION TEMPERATURE AND TIME ON NANOPARTICLES MORPHOLOGY CONTAINS AVERAGE NANOPARTICLES DIAMETER AND ITS DISPERSION COEFFICIENT PREPARED BY SEEDED POLYMERIZATION METHOD. TEMPERATURE PARAMETER WAS CHANGED IN 2 DIFFERENT VALUES AND TIME PARAMETER WAS CHANGED IN 4 VARIOUS VALUES AND THEIR EFFECTS HAVE INVESTIGATED. THE MORPHOLOGY OF PARTICLES WERE OBSERVED BY SEM MICROSCOPY AND SIZE OF PARTICLES DIAMETER MEASURED BY IMAGEJ SOFTWARE ACCORDING TO SCALE. RESULTS SHOWED THAT INCREASING PROCESS TEMPERATURE LEADS AVERAGE PARTICLES DIAMETER AND DISPERSION COEFFICIENT TO BE INCREASED. ALSO, IT SEEMS AVERAGE PARTICLES DIAMETER AND DISPERSION COEFFICIENT HAVE INCREASED OVER TIME.

IN THIS STUDY, THE POLY (METHYL METHACRYLATE)/POLYSTYRENE (PMMA/PS) CORE/SHELL POLYMER PARTICLES WERE SYNTHESIZED BY SEEDED DISPERSION POLYMERIZATION OF STYRENE ON A PMMA SEED (3.98 MM, RATIO OF 3.1 W/W) USING AZOBISISOBUTYRONITRILE(AIBN) AND POLYVINYLPYRROLIDONE(PVP) AS INITIATOR, AND STABILIZER RESPECTIVELY, IN WATER/METHANOL MEDIUM(RATIO 1/4 W/W) AT VARIOUS TEMPERATURES. IT WAS FOUND THAT AT HIGHER TEMPERATURES, THE SHELL WAS THICKER, AND THE SECONDARY NUCLEATION SUPPRESSED. THE PARTICLES SYNTHESIZED WERE COMPLETELY SPHERICAL.

NOVEL POLYMER PARTICLES WHICH HAVE BEEN SYNTHESIZED IN RECENT YEARS HAVE FOUND APPLICATIONS IN MANY FIELDS, INCLUDING BIOMEDICAL, DRUG DELIVERY SYSTEMS, SURFACTANTS, MICROELECTRONICS TO NAME A FEW. THEY ARE PRODUCED USING SEVERAL METHODS INCLUDING (SEEDED) EMULSION, (SEEDED) DISPERSION, AND SUSPENSION POLYMERIZATIONS. HOWEVER, SEEDED DISPERSION POLYMERIZATION (SDP) IS FAVORABLE, IN WHICH THEIR SYNTHESIS ARE ACCOMPLISHED IS TWO STEPS. IN THE FIRST STAGE, SEED IS PRODUCED, WHICH UPON ADDITION OF THE SECOND MONOMER, IS TRANSFORMED TO COMPOSITE PARTICLES. IN THIS ARTICLE, SDP IS PERFORMED USING TWO TYPES OF SEED PARTICLES, AND THE EFFECT OF INITIATOR CONCENTRATION ON THE FINAL MORPHOLOGY IS INVESTIGATED.

A CONVENIENT METHOD FOR THE SYNTHESIS OF POLYMERIC PARTICLES IS SEEDED DISPERSION POLYMERIZATION (SDP) WHICH IS CARRIED OUT IN TWO STAGES. THUS, A SEED OF POLYMER PARTICLES IS PRODUCED IN THE FIRST STAGE, AND IN A SECOND STAGE UPON ADDITION OF THE SECOND MONOMER, COMPOSITE PARTICLES ARE SYNTHESIZED. IN THIS STUDY, THE POLYMER PARTICLES WERE SYNTHESIZED USING THE SDP METHOD WITH TWO KINDS OF SEEDS AND THE EFFECT OF (PVP) CONCENTRATION ON MORPHOLOGY WAS STUDIED.