Preparation Of Polyacrylate Type Shape Memory Polymer Crosslinked Through Hydrogen Bonds

In this paper,shape memory materials were synthesized using acrylates polymers and nano-clay particles which acted as reinforcing phase as raw materials.Furthermore,the shape memory behavior of the materials was deeply studied.The effect of monomer type and ratio on the properties of shape memory polymers was investigated to prepare polymer materials with better shape memory effects.The effect of nano-clay content on the structure and properties of the material were studied.The mechanism of the influence of nano-clay on materials mechanical properties and shape memory effect were proposed.These studies are of great significance for extending the service life,increasing the times of recycling,and expanding the application fields of materials.The main contents are summarized as follows:(1)The excellent shape memory MD-NC hydrogels have been readily prepared using methoxyethyl acrylate(MEA)and N,N-dimethylacrylamide(DMAA)as raw materials,and nano-clay particles(NC)as reinforcing phase.The physical cross-linking MD-NC hydrogels with excellent elastic(the stress of all samples is over 1000.00%),temperature-dependence transmittance(the transmittance is more than 90%and has a positive correlation with temperature),and controllable swelling performance.Based on the controllable swelling performance and mechanical stability,the swelling induced shape recovery process could be finished within 1 h without any obvious difference between virgin swelling shape and recuperative shape.The MD50-NC2 has the best comprehensive performance with a stress of 217.71 KPa and a strain of 1813.72%.(2)On the basis of MD-NC hydrogels,the raw materials are improved.MA shape memory polymers with excellent shape memory effect,high mechanical strength,and fast self-healing ability were readily prepared by free-radical copolymerization of Poly(ethylene glycol)methyl ether acrylate(MPEG)and 4-Acryloylmorpholine(ACMO).Experiments show that the glass transition temperature and mechanical properties of the material can be easily adjusted by adjusting the monomer ratio.The shape memory polymers with fast healing speed(40 s),Low healing temperature(room temperature),high healing efficiency(99.76%),well mechanical properties(stress is 4.21 MPa and strain is 725.81%)and good shape memory effect have been successfully prepared.(3)The nano-clay particles were combined with the MA matrix,and a shape memory polymer composites with good shape memory effect and enhanced mechanical strength were successfully prepared.While maintaining good self-healing ability of MA matrix(after healing 1 minute at room temperature,the stress is 5.65 MPa and R_?as high as 99.30%,the strain is 535.11%and R_?as high as 98.88%),the mechanical properties and the capability of shape recovery of the material are improved remarkably,and allows the material to exhibit the dual responsive properties of water-sensitive and thermal-sensitive.The shape recovery rate was 83%when the sample was thermally responsive at 37?for 120 s;the shape recovery rate was 80%when the sample responded to water at 37?for 60s.