Study On The Emulsion Polymerization With Photo-irradiated Systems Based On Tertiary Amine Oxide

Emulsion polymerization is one of the most common methods used to prepare the polymer in the industrial production. But conventional emulsion polymerization is initiated by heat, meanwhile it require higher temperatures and longer reaction time, and can not regulate polymerization; Photoinitiated polymerization is commonly carried out by the body or solution polymerization, and the cost of photoinitiator is higher, so it is difficult to achieve the industrialized production. Generally photoinitiated polymerization require lower reaction temperature and shorter reaction time, so how to achieve photoinitiated emulsion polymerization is a hot research field in recent years.In this paper, the emulsion polymerization initiated by ultraviolet light was carried out by using the octadecylamine polyoxyethylene (5) oxide (tertiary amine oxides, abbreviated OA-1805) prepared by our own group as emulsifier, styrene as monomer, water as the continuous phase, without any additives. In the polymerization initiated by the visible light, additional cyanine dye was added as photoinitiator. The polymer molecular weight and distribution, structure and polymerization mechanism were examined and researched by GPC, FT-IR, NMR, DSC, MS and so on.In the polymerization initiated by UV, the polymerization reaction of styrene could occur at 5?, the conversion rate increased with increasing temperature and the increasing light intensity. At 20?, after 8 hours, the conversion rate could reach 70%. In this systems, the molecular weight of polystyrene could reach more than one million, belong to high molecular weight polystyrene, the molecular weight distribution was between 1.7 and 2.0. The structure of the polymer prepared by the system was not much different from the conventional polystyrene.In the polymerization initiated by the visible light, the basic formula of the UV polymerization was treated as the standard, the molar ratio of initiator and monomer ratio was 0.75:10000, the dosage of emulsifier was 2 times, the mass ratio of monomer and water ratio was 1:6, the effect of polymerization was best. At 20 ?, after 8 hours, the conversion rate could reach 70%. The molecular weight of the polymer prepared in the visble system was lower than the polymer prepared in the UV system, the molecular weight was about 600000, and the molecular weight distribution is also slightly wider, about 2.0. The structure of the polymer prepared by the system was also not much different from the conventional polystyrene.In the UV initiation system, the OA-1805 played a role of emulsifiers, but also played a role in initiating polymerization. In visible light initiation system, through studying of H2O2, OA-1805 and dye, it was found that the system could initiate polymerization in the presence or absence of H2O2, it was initiated by the binary initiator system composed of OA-1805 with dye jointly. The OA-1805 played a role of emulsifiers, but also played a role in initiating polymerization. This cheap emulsifier provided a new direction about the study of polymerization initiated by visible light.