A Double Network Hydrogel with High Mechanical Strength and Shape Memory Properties  

具有双网络结构高强度和形状记忆水凝胶（英文）

作　　者：Lei Zhu Chun-ming Xiong Xiao-fen Tang Li-jun Wang Kang Peng Hai-yang Yang 

机构地区：[1]CAS Key Laboratory of Soft Matter Chemistry,School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,China [2]Research Institute of Science and Technology,China National Petroleum Corporation,Beijing 100083,China

出　　处：《Chinese Journal of Chemical Physics》2018年第3期350-358,368,共10页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China (No.51273189);the National Science and Technology Major Project of the Ministry of Science and Technology of China (No.2016ZX05016),the National Science and Technology Major Project of the Ministry of Science and Technology of China (No.2016ZX05046)

摘　　要：Double network(DN)hydrogels as one kind of tough gels have attracted extensive at-tention for their potential applications in biomedical and load-bearing fields.Herein,we import more functions like shape memory into the conventional tough DN hydro-gel system.We synthesize the PEG-PDAC/P(AAm-co-AAc)DN hydrogels,of which the first network is a well-defined PEG(polyethylene glycol)network loaded with PDAC(poly(acryloyloxyethyltrimethyl ammonium chloride))strands,while the second network is formed by copolymerizing AAm(acrylamide)with AAc(acrylic acid)and cross-linker MBAA(N;N′-methylenebisacrylamide).The PEG-PDAC/P(AAm-co-AAc)DN gels exhibits high mechanical strength.The fracture stress and toughness of the DN gels reach up to 0.9 MPa and 3.8 MJ/m^3,respectively.Compared with the conventional double network hydrogels with neutral polymers as the soft and ductile second network,the PEG-PDAC/P(AAm-co-AAc)DN hydrogels use P(AAm-co-AAc),a weak polyelectrolyte,as the second network.The AAc units serve as the coordination points with Fe^3+ions and physically crosslink the second network,which realizes the shape memory property activated by the reducing ability of ascorbic acid.Our results indicate that the high mechanical strength and shape memory properties,probably the two most important characters related to the potential application of the hydrogels,can be introduced simultaneously into the DN hydrogels if the functional monomer has been integrated into the network of DN hydrogels smartly.Double network（DN） hydrogels as one kind of tough gels have attracted extensive attention for their potential applications in biomedical and load-bearing fields. Herein,we import more functions like shape memory into the conventional tough DN hydrogel system. We synthesize the PEG-PDAC/P（AAm-co-AAc） DN hydrogels, of which the first network is a well-defined PEG（polyethylene glycol） network loaded with PDAC（poly（acryloyloxyethyltrimethyl ammonium chloride）） strands, while the second network is formed by copolymerizing AAm（acrylamide） with AAc（acrylic acid） and cross-linker MBAA（N, N’-methylenebisacrylamide）. The PEG-PDAC/P（AAm-co-AAc） DN gels exhibits high mechanical strength. The fracture stress and toughness of the DN gels reach up to 0.9 MPa and 3.8 MJ/m3, respectively. Compared with the conventional double network hydrogels with neutral polymers as the soft and ductile second network, the PEG-PDAC/P（AAm-coAAc） DN hydrogels use P（AAm-co-AAc）, a weak polyelectrolyte, as the second network.The AAc units serve as the coordination points with Fe3+ ions and physically crosslink the second network, which realizes the shape memory property activated by the reducing ability of ascorbic acid. Our results indicate that the high mechanical strength and shape memoryproperties, probably the two most important characters related to the potential application of the hydrogels, can be introduced simultaneously into the DN hydrogels if the functional monomer has been integrated into the network of DN hydrogels smartly.

关 键 词：DOUBLE NETWORK HYDROGEL WEAK POLYELECTROLYTE High mechanical strength Shape MEMORY properties 

分 类 号：O64[理学—物理化学]