Studies On Preparation And Properties Of PAMAM-PEG-PAMAM

Polymer electrolytes attract more and more scholars from around the world in view of their prospect applications in the field of lithium ion battery,dye-sensitized solar cell,etc.The energy barrier is leaped with the help of the lithium ion dissolved in the polymer,which makes the lithium ion directional migration in the electric field form electric current.Thus,the conductivities of polymers are largely dependent on the low degree of crystallinity and carrier concentration.By now,how to degrade the crystallinity and simultaneously increase the carrier concentration of Polymer is the research focus of this discipline.Within the present paper,we first fabricate a linear-dendritic copolymer(PAMAM-PEG-PAMAM)by Michael addition and amidation,and then conduct a thorough discussion on the influence of the structure and numbers of end groups.After that,cellulose-based ionogels is made by cross-linked.Utilizing the equipment,including scanning electron microscope(SEM),thermal gravimetric analysis(TGA),rheology,tensile tests,and AC impedance,we analyzed the morphology,mechanical,electrochemical,and thermal properties.The innovative conclusions of current thesis are summarized as follows:1.PAMAM-PEG-PAMAM was synthesized through Michael addition and amidation,and crystallization morphology was investigated with POM.It is observed that the half-generation polymer was not changed with the increased volume of PAMAM,but the full generation had greatly changed,especially with G3.0 where a phase separation is seen.2.The melting points increase with the increment of the generation,however,the crystallization rate decreased because of the strong formation groups of hydrogen-bonds.3.The thermal stability decreased with generation of polymer increasing.The viscosity of half-generation of PAMAM-PEG-PAMAM doesn't change under different shear rate,but the viscosity of the full generation exhibits stronger shear thinning behavior.4.The results indicate that the obtained cross-linked cellulose-based ionogels have nanoporous mesh architecture,and can reach a high ionic conductivity of 6.3×10^-3S/cm.Further,the ionogels have good mechanical properties and their tensile strength can even reach up to 9.6MPa.Rheological results suggest that the ionogels show high temperature robustness and the modulus reaches 1.7×10⁵ Pa at 200 ^oC.TGA results indicate that the ionogels have high thermal stability and the decomposition temperature reaches 251.2^oC.The method used in this study makes an effective way to fabricate high-performance gel polymer electrolyte.