Study Of CO₂-Induced Reversible Liquid-Solid Transformation Of Photopolymerization System

With the development of activities of industry and agriculture, the emission of greenhouse gases has been increasing, which CO2contributed the most, leading to a exacerbating greenhouse effect that will bring climate change and influence on human’s existence and development. Therefore, in recent decades, our scientists have been committed to study on separating, storing and exploiting CO2more efficiently, scientifically, environmentally and economically. In the last decade, a number of polymers that use CO2as the carbon source have been worked out, among which the most impressive one is the CO2-induced responsive polymer. That is because the CO2gas is atoxic, stable and extremely abundant, which makes the CO2-induced responsive polymer has a great application future in controlled drug release, biomimetic materials, biosensors, smart coatings, smart surface and smart surfactant.In this paper, hanging on to the new trends of the C02-responsive polymer study, combining with the advantages of photopolymerization system, starting with the point of reversible liquid-solid transformation of Photopolymerization System, the photopolymerizable oligomers and monomer diluents containing primary and secondary amine were designed and synthesized and those reversible responsiveness of CO2-N2and CO2-hcating were focused on. The main innovations of the research results are as follows.1.The photopolymerizable oligomers and monomers with CO2responsive reversibility were synthesized for the first time.2.The oligomer solution had a brilliant CO2-N2responsive reversibility. The CO2response was instant, which finished60%in the first12s and the rest40%after420s; but the N2response needed1200s to finish and restore to the original state.The reversible responsiveness didn’t weaken after repeated ten times.3.The oligomer film had a good CO2-heating responsive reversibility.The pendulum hardness of the film increased from0.065to0.14and almost restored to the original state after heating up to50℃for60min.4. With the amine content of the oligomer growing, its glass transition temperature (Tg) firstly descended and then ascended. Because when the primary amine content was little, its increase would bring the raise of polymer chains’ motility which led to its Tg reduction. When the primary amine content was large, continuing raising the content brought intermolecular hydrogen bond. Therefore the polymer chains’motility decreased and its Tg went up.5.The monomer diluent had an excellent responsive reversibility to CO2-N2. First50s was CO2induction period. Then the response began progressively and completed within approximately360s. Its N2response sensitivity was pretty high. It started immediately when N2was just put into and used about600s to finish and restore to the original state.