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Preparation and Characterization of Composite Polymer Particles

Author: ZhangLiBin
Tutor: KongXiangZheng
School: Jinan University
Course: Polymer Chemistry and Physics
Keywords: Emulsion Polymerization Cation functional monomer Electrostatic interactions Different cohesion Strawberry -type composite particles
CLC: O631.3
Type: Master's thesis
Year: 2010
Downloads: 44
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Abstract

In this paper, different condensation method to prepare a special surface microstructure of the polymer composite particles, and to explore effective methods that can effectively control the microstructure. The research content of this paper is divided into three areas: the preparation of cationic colloidal particles and particle size control; the anionic colloidal preparation and particle size control; preparation of composite particles and the structure of control. First, 1 - bromohexadecane and N, N-dimethyl amino ethyl methacrylate as raw materials, the synthesis of the cationic functional monomer methacryloxypropyl ethyl cetyl dimethyl ammonium bromide (DMHB ). Using infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, elemental analyzer, surface tension meter and conductivity meter DMHB relevant characterization, to determine with a reactive double bond in its molecular structure, the critical micelle concentration (CMC) of 6.7 × 10-4 mol / L. The cation radical initiator, changing the DMHB the amount of the cationic functional monomer and styrene (St) for the emulsion polymerization to obtain different particle size P (St-DMHB) cation Nanocolloids of. The results show that the final latex particle regularity smaller with the increase in DMHB dosage the the dry colloidal particle size controllable range was 28 to 74 nm; latex particle ζ increased the potential with DMHB dosage first increases and then, to DMHB dosage 2% of the total monomer mass no longer changes. Then, by the batch method polymerization, the initiator of methyl methacrylate (MMA) or St anionic polymerization of different diameter submicron micelles potassium persulfate (KPS). The amount of initiator, polymerization temperature, the amount of emulsifier and monomer properties influencing factors. The results shows that increasing the amount of initiator used to help to improve the polymerization rate, but has little effect on the latex particles; improve the polymerization reaction temperature is advantageous to improve the polymerization rate, reducing the particle size of the latex; PMMA obtained in the absence of any emulsifiers the dry particle size of the latex particles controllable range of 150 ~ 220nm; particle size can be obtained by adjusting the amount of emulsifier dry when the use of emulsifiers, controllable changes in the range between 75 ~ 200nm PMMA latex particles PSt latex particles with a controllable variation range of the dry particle size of 90 ~ 800nm. Semi-continuous emulsion prepared poly (St-butyl acrylate) micelles, reduce the amount of emulsifier, favor larger latex particles, reduce secondary nucleation probability; constantly dropping monomer latex particles can be continue to grow, but the micelles grow up to a certain extent, are more likely to produce adhesions, hydration particle size controllable range 54 ~ 172nm. Micelles contained in the negative charge introduced by the initiator residues, ζ potential does not change varies with the polymerization conditions, and substantially constant around-48mV. Finally, the use of the agglutination method based on different electrostatic interactions of the above two with the opposite charge of the micelles to be assembled, the surface roughness of strawberry-type composite particles can be obtained, with the shell cationic micelles particle size decreases, the composite fine particles surface roughness becomes low. Track testing different condensation process in composite liquid light transmittance and particle size distribution, and the shape, size and surface morphology of cationic micelles, anionic colloidal particles, and composite particles observed by transmission electron microscopy and scanning electron microscopy. The results show the number of unit surface of the composite fine particles of cationic micelles controllable change within a certain range can be realized by changing the proportion of anionic latex particles and a cationic latex particles. The deposition of particles having different surface morphology in the polymer film, the measured film surface water contact angle change. The results show that the deposition the strawberry type polymer particles the surface of the film contact angle than the smooth surface of the film of the polymer particles is deposited, a large contact angle, indicating that the surface of the secondary structure is conducive to enhance the surface of the hydrophobic properties of the membrane material.

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