Ionic Self-Healing Materials and High-Performance Transparent Materials Based on Ring-Opening Metathesis Polymerization

Author:Cui Jing

Supervisor:li yue sheng

Database:Doctor

Degree Year:2017

Download:64

Pages:185

Size:10974K

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With the continuous progress of society,people are more and more in pursuit of excellent material performance.Materials are required to not only meet a special application,but also own a wide range of performance.Ring-opening metathesis polymerization(ROMP)has become a conventional polymerization method.Grubbs catalysts have high catalytic activity and polarity tolerance,greatly broadening the range of monomers used for ROMP polymerization.In this dissertation,functionalized norbornene derivative monomers were designed.A seires of novel ionic self-healing materials with unexceptionable repairing performance and mechanical properties and the transparent cycloolefin polymers(COPs)with high performance were prepared via ROMP by using Grubbs catalysts.The prepared materials have a significant potential practical application.The specific research contents were listed as follows:1.Polymerized ionic liquids(PILs)with different counterions were synthesized via ring-opening metathesis polymerization(ROMP).The ionic associations in polymer matrix served as physical cross-links,restricting the mobility of the surrounding polymer chain,improving the mechanical strength and imparting the self-healing behavior.To balance the mechanical property and healing performance,PIL blends with appropriate T_gs were prepared by simply blending a high T_g PIL with varying amount of a low T_g PIL.Moderate ion aggregation was beneficial for repair properties.2.A novel type of ionic self-healing materials containing gradient-distributed imidazoliums with rigid motifs were synthesized via ring-opening metathesis polymerization,which combined rapid healing performance with excellent mechanical properties-high Young’s modulus of 286 MPa,high yield stress of 16.2 MPa,high toughness and excellent extensibility.To the best of our knowledge,such high Young’s modulus and yield stress had not been achieved for the self-healing supramolecular materials before.By adjusting the fractions of imidazoliums and rigid motifs,the materials can be tuned to repair even at room temperature.Furthermore,thermal stimulus,microwave and near-infrared irradiations can greatly promote the healing process.More remarkably,the self-healing functionality of copolymers was demonstrated to resist separation time and water,maintaining persistent healing performance.3.Gradient,diblock and triblock copolymers were successfully obtained by ROMP.By adjusting the distribution of the two structural units in the copolymers and the length of the alkyl chain in the imidazolium-based norbornene derivatives,the precise control of the mechanical and healing properties of the copolymer material was achieved.The copolymer exhibited good repair performance thanks to"ion hopping".4.Novel ester group functionalized cyclic olefin polymers(COPs)with high glass transition temperature,high transparency,good mechanical performance and excellent film forming ability have been achieved in this work via efficient ROMP.The T_gs and hydrophilicity of copolymers could be modulated by changing the comonomers incorporation.5.The COPs were obtained via ROMP.The highest T_g(up to 277°C)of hydrogenated polymer H-PM3 is achieved,which is so far the highest value obtained by the ROMP approach,to the best of our knowledge.Furthermore,all the hydrogenated polymers show excellent transparency.In summary,this thesis has successfully constructed a series of new ion self-repairing materials and high-performance transparent cyclic olefin materials to meet the needs of society and special occasions.