Polymerization of vinyl chloride in the presence of nanofillers – effects on the shape
and morphology of PVC grains
Polimery 2006, No 2, 133
Suspension polymerization of vinyl chloride has been carried out in the presence of various types of nanofillers chosen from clays, silica (pure or functionalized), silicone polymer or hybrid core/shell ones. Nanofillers used in VC polymerization significantly influence the structure and shape of PVC grain: from typical one in case of control sample and in the presence of silica to "cake-like” in case of functionalized silica, "sea-shells” with silicone polymer use or "balls” and "dented balls” - not typical for suspension PVC - in the presence of hybrid core/shell particles. The last ones look just as emulsion PVC although were prepared in suspension polymerization process. It has been found, using SEM and TEM methods, that distribution of nanofiller in polymer was rather uniform. MMT is semiintercalated/semiexfoliated in PVC grain. Some regions showing mesoporosity were also found (especially in the presence of silica) suggesting the formation of more ordered structures in the grain. We can foresee that not only the presence and distribution of nanofillers in PVC grain but also the change of PVC grain shape caused by them can both influence the final properties of PVC and its processability.
Key words: suspension VC polymerization, nanofillers, silica, montmorillonite, core/shell hybrid nanofillers, PVC grain morphology, mesoporosity
Polymerization of vinyl chloride in the presence of nanofillers - effects on the shape and morphology of PVC grains