Polyacrylamide Particles And Polymer Blends Prepared By Dispersion Polymerization

In this paper, micron-sized PAM spheres have been firstly prepared through the dispersion polymerization of acrylamide. These PAM spheres exhibited regular shape and narrow dispersity. The size of over 70% PAM spheres were between 1.5-2.0μm and the value of polydispersity index (PDI) was 1.17. The average particle size of PAM spheres became larger with the increase of monomer concentration, the decrease of stabilizer concentration, the increase of initiator concentration and the decrease of ethanol/water ratio.Then, based on our former experiments, the polymer blends of Poly (acylamide- acrylic acid)/ Poly (vinyl pyrrolidone) were synthesized by dispersion polymerization, using acrylamide and acrylic acid as monomers, poly (vinyl pyrrolidone) as dispersant, AIBN as initiator. FTIR test revealed that acylamide and acrylic acid were successfully polymerized. SEM and TEM tests suggested that the resulting P(AM-AA) microspheres with diameters between 200-300nm were well dispersed in the PVP matrix. Thermal analyses and the XRD showed that with the increase of acrylic acid content, the diameters of the microspheres decreased and the miscibility of the polymer blends well improved. Comparing the mechanical properties of P(AM-AA)/ PVP polymer blends with different ratio of acylamide to acrylic acid, it was found that the blends had better mechanical properties with the increase of acrylic acid content and the increase of the molecular weight of PVP.Adding PEG200DMA as crosslinker, PAM/PVP-PEG200DMA polymer blends were prepared by dispersion polymerization. It was discovered that when the content of PEG200DMA was low, it could help to well disperse PAM particles. And with the increase of PEG200DMA content, the miscibility of the matrix and the dispersed phase was visibly improved. However, the reaction will not happen if the content exceeded a critical value. Comparing the mechanical properties of PAM/PVP-PEG200DMA polymer blends using PVP with different molecular weights as stabilizer, it was found that the higher the molecular weight of PVP, the larger range of PEG200DMA could be used and the blends will also have better mechanical properties with the increase of the molecular weight of PVP.