基于遥爪型大分子交联剂的动态化学交联水凝胶的黏弹性质
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摘要
以壳聚糖为主链,以双端苯醛基聚乙二醇(DF-PEG)为交联剂,以希夫碱为动态交联键制备了动态化学交联水凝胶,通过改变大分子交联剂的分子量和浓度调控凝胶网络结构。以旋转流变仪的动态频率扫描和稳态剪切为主要手段,研究了凝胶结构对凝胶模量、松弛时间、剪切增稠程度的影响。结果表明:DF-PEG的分子量和浓度会影响凝胶网络内弹性活性链的密度从而影响模量、松弛时间,而凝胶剪切增稠程度与弹性活性链密度密切相关。
Hydrogels with dynamic chemical crosslinking are obtaining more and more attention in the field of functional polymer materials.To rationally control the functions of the material,it is important to understand the relationship between viscoelastic properties and network structure comprehensively.In this work,dynamic chemical crosslinking hydrogel was prepared using chitosan as the backbone,dibenzaldehyde poly(ethylene glycol)(DF-PEG)as the macromolecular cross-linker and Schiff's base as the dynamic cross-linking bond.The network structure and the viscoelasticity were thus tailored by regulating the molecular weight and the concentration of telechelic macro-crosslinker,and the linear and non-linear rheological properties were studied with a rotational rheometer.The linear rheological results show that the storage modulus of hydrogel increases with the increase of molecular weight or the concentration of DF-PEG,because DF-PEG has higher probability to connect with two different chitosan backbones and creates elastic-active crosslinking as the molecular weight or the concentration of DF-PEG increases.The relaxation time of the hydrogels exhibits the similar dependence on the molecular weight or the concentration of DF-PEG,in reminiscent of the"Sticky Reptation"mechanism of associative polymer chains.An interesting shear thickening phenomenon is observed on the as-prepared hydrogel,and the magnitude of shear-thickening decreases with the increase of concentration or the molecular weight of DFPEG.It can be explained by a mechanism of shear-induced transition from non-elastic-active crosslinker to elastic-active crosslinker.The current study unveiled the relationship between network structure and viscoelasticity of hydrogel,which would guide the design of functional hydrogels.
Hydrogels with dynamic chemical crosslinking are obtaining more and more attention in the field of functional polymer materials.To rationally control the functions of the material,it is important to understand the relationship between viscoelastic properties and network structure comprehensively.In this work,dynamic chemical crosslinking hydrogel was prepared using chitosan as the backbone,dibenzaldehyde poly(ethylene glycol)(DF-PEG)as the macromolecular cross-linker and Schiff's base as the dynamic cross-linking bond.The network structure and the viscoelasticity were thus tailored by regulating the molecular weight and the concentration of telechelic macro-crosslinker,and the linear and non-linear rheological properties were studied with a rotational rheometer.The linear rheological results show that the storage modulus of hydrogel increases with the increase of molecular weight or the concentration of DF-PEG,because DF-PEG has higher probability to connect with two different chitosan backbones and creates elastic-active crosslinking as the molecular weight or the concentration of DF-PEG increases.The relaxation time of the hydrogels exhibits the similar dependence on the molecular weight or the concentration of DF-PEG,in reminiscent of the"Sticky Reptation"mechanism of associative polymer chains.An interesting shear thickening phenomenon is observed on the as-prepared hydrogel,and the magnitude of shear-thickening decreases with the increase of concentration or the molecular weight of DFPEG.It can be explained by a mechanism of shear-induced transition from non-elastic-active crosslinker to elastic-active crosslinker.The current study unveiled the relationship between network structure and viscoelasticity of hydrogel,which would guide the design of functional hydrogels.
引文
[1]吴唯,陈玉洁,王佳伟,等.多重氢键网络结构超分子聚合物的合成与性能[J].功能高分子学报,2011,24(4):411-415.
[2]顾文娟,陆亚明,张幼维,等.PMAA纳米水凝胶的水相制备[J].功能高分子学报,2016,29(1):61-67.
[3]刘维伊,李雪婷,赵迪,等.羧基含量对孔胶自组装形成光电子晶体质量的影响[J].功能高分子学报,2016,29(4):397-403.
[4]YOUNT W C,LOVELESS D M,CRAIG S L.Small-molecule dynamics and mechanisms underlying the macroscopic mechanical properties of coordinatively cross-linked polymer networks[J].Journal of the American Chemical Society,2005,127(41):14488-14496.
[5]LOVELESS D M,AND S L J,CRAIG S L.Rational control of viscoelastic properties in multicomponent associative polymer networks[J].Macromolecules,2005,38(24):10171-10177.
[6]YOUNT W C,LOVELESS D M,CRAIG S L.Strong means slow:Dynamic contributions to the bulk mechanical properties of supramolecular networks[J].Angewandte Chemie,2005,44(18):2746-2748.
[7]王亮,郭成功,王彩旗.基于β-环糊精和二茂铁主客体作用的超分子聚合物的制备及其凝胶化[J].功能高分子学报,2012,25(4):335-341.
[8]LIAO X,CHEN G,LIU X,et al.Photoresponsive pseudopolyrotaxane hydrogels based on competition of host-guest interactions[J].Angewandte Chemie,2010,49(26):4409-4413.
[9]SIMON K A,WARREN N J,MOSADEGH B,et al.Disulfide-based diblock copolymer worm gels:A wholly-synthetic thermo-reversible 3D matrix for sheet-based cultures[J].Biomacromolecules,2015,16(12):3952-3958.
[10]WEI C,CHEN M,LIU D,et al.A recyclable disulfide bond chemical cross-linking high toughness,high conductivity ion gels based on re-shaping and restructuring in gel state[J].Polymer Chemistry,2015,6(22):4067-4070.
[11]MUKHERJEE S,HILL M R,SUMERLIN B S.Self-healing hydrogels containing reversible oxime crosslinks[J].Soft Matter,2015,11(30):6152-6161.
[12]COLLINS J,NADGORNY M,XIAO Z,et al.Doubly dynamic self-healing materials based on oxime click chemistry and boronic acids[J].Macromolecular Rapid Communications,2017,38(6):1600760.
[13]吕展,郭赞如,贺站锋,等.基于酰腙可逆共价键制备溶胶-凝胶转变的可自愈合水凝胶[J].功能高分子学报,2015,28(4):373-379.
[14]CHAO A,NEGULESCU I,ZHANG D.Dynamic covalent polymer networks based on degenerative imine bond exchange:Tuning the malleability and self-healing properties by solvent[J].Macromolecules,2016,49(17):6277-6284.
[15]MURPHY E B,WUDL F.The world of smart healable materials[J].Progress in Polymer Science,2010,35(1):223-251.
[16]SIJBESMA R P,MEIJER E W.Reversible polymers formed from self-complementary monomers using quadruple hydrogen bonding[J].Science,1997,278(5343):1601-1604.
[17]CORDIER P,TOURNIHAC F,SOULI-ZIAKOVIC C,et al.Self-healing and thermoreversible rubber from supramolecular assembly[J].Nature,2008,451(7181):977-980.
[18]TAYLOR D L,IN H P M.Self-healing hydrogels[J].Advanced Materials,2016,28(41):9060-9093.
[19]LU W,LE X,ZHANG J,et al.Supramolecular shape memory hydrogels:A new bridge between stimuli-responsive polymers and supramolecular chemistry[J].Chemical Society Reviews,2017,46(5):1284-1294.
[20]LI J,VIVEROS J,WRUE M,et al.Shape-memory effects in polymer networks containing reversibly associating sidegroups[J].Advanced Materials,2010,19(19):2851-2855.
[21]BINDER W H,PETRARU L,ROTH T,et al.Magnetic and temperature-sensitive release gels from supramolecular polymers[J].Advanced Functional Materials,2010,17(8):1317-1326.
[22]KAMALY N,YAMEEN B,WU J,et al.Degradable controlled-release polymers and polymeric nanoparticles:Mechanisms of controlling drug release[J].Chemical Reviews,2016,116(4):2602-2663.
[23]RUBINSTEIN M,SEMENOV A N.Dynamics of entangled solutions of associating polymers[J].Macromolecules,2001,34(4):1058-1068.
[24]RUBINSTEIN M,DOBRYNIN A V.Solutions of associative polymers[J].Trend in Polymer Science,1997,5(6):181-186.
[25]MARRUCCI G,BHARGAVA S,COOPER S L.Models of shear-thickening behavior in physically crosslinked networks[J].Macromolecules,1993,26(26):6483-6488.
[26]XU D,CRAIG S L.Multiple dynamic processes contribute to the complex steady shear behavior of cross-linked supramolecular networks of semidilute entangled polymer solutions[J].Journal of Physical Chemistry Letters,2010,1(11):1683-1686.
[27]XU D,CRAIG S L.Scaling laws in supramolecular polymer networks[J].Macromolecules,2011,44(13):5465-5472.
[28]XU D,CRAIG S L.Strain hardening and strain softening of reversibly cross-linked supramolecular polymer networks[J].Macromolecules,2011,44(18):7478-7488.
[29]XU D,HAWK J L,LOVELESS D M,et al.Mechanism of shear thickening in reversibly cross-linked supramolecular polymer networks[J].Macromolecules,2010,43(7):3556-3565.
[30]XU D,LIU C Y,CRAIG S L.Divergent shear thinning and shear thickening behavior of supramolecular polymer networks in semidilute entangled polymer solutions[J].Macromolecules,2011,44(7):2343-2353.
[31]JIN L,TAN Y,SHANGGUAN Y,et al.Multiregion shear thinning for subsequent static self-thickening in chitosangraft-polyacrylamide aqueous solution[J].Journal of Physical Chemistry B,2013,117(48):15111-15121.
[32]JIN L,SHANGGUAN Y,YE T,et al.Shear induced self-thickening in chitosan-grafted polyacrylamide aqueous solution[J].Soft Matter,2013,9(6):1835-1843.
[33]CHOH S Y,CROSS D,WANG C.Facile synthesis and characterization of disulfide-cross-linked hyaluronic acid hydrogels for protein delivery and cell encapsulation[J].Biomacromolecules,2011,12(4):1126-1136.
[34]YANG Q,WANG P,ZHAO C,et al.Light-switchable self-healing hydrogel based on host-guest macro-crosslinking[J].Macromolecular Rapid Communications,2017,38(6):1600741.
[35]ZHANG Y,TAO L,SHUXI L,et al.Synthesis of multiresponsive and dynamic chitosan-based hydrogels for controlled release of bioactive molecules[J].Biomacromolecules,2011,12(8):2894-2901.
[36]FERRY J D.Viscoelastic Properties of Polymers[M].New Jerssy:John Wiley&Sons,1980.
[37]RUBINSTEIN M,COLBY,R H.Polymer Physics[M].New York:Oxford University Press,2003.
[38]LEIBLER L,RUBINSTEIN M,COLBY R H.Dynamics of reversible networks[J].Macromolecules,1991,24(16):4701-4707.
[39]YANG H,YU K,MU X,et al.A molecular dynamics study of bond exchange reactions in covalent adaptable networks[J].Soft Matter,2015,11(31):6305-6317.
[40]GROOT R D,AGTEROF W G M.Dynamic viscoelastic modulus of associative polymer networks:Off-lattice simulations,theory and comparison to experiments[J].Macromolecules,1995,28(18):6284-6295.
[41]NG W K,TAM K C,JENKINS R D.Lifetime and network relaxation time of a HEUR-C20associative polymer system[J].Journal of Rheology,2000,44(44):137-147.
[42]AND Y U,MACDONALD P M.NMR diffusion and relaxation time studies of HEUR associating polymer binding to polystyrene latex[J].Macromolecules,1995,29(1):63-69.
[43]GONZ LEZ A E.Viscosity of ionomer gels[J].Polymer,1983,24(1):77-80.
[44]GONZ LEZ A E.Viscoelasticity of ionomer gels:2.The elastic moduli[J].Polymer,1984,25(10):1469-1474.
[45]HUANG G,ZHANG H,LIU Y,et al.Strain hardening behavior of poly(vinyl alcohol)/borate hydrogels[J].Macromolecules,2017,50(5):2124-2135.
[2]顾文娟,陆亚明,张幼维,等.PMAA纳米水凝胶的水相制备[J].功能高分子学报,2016,29(1):61-67.
[3]刘维伊,李雪婷,赵迪,等.羧基含量对孔胶自组装形成光电子晶体质量的影响[J].功能高分子学报,2016,29(4):397-403.
[4]YOUNT W C,LOVELESS D M,CRAIG S L.Small-molecule dynamics and mechanisms underlying the macroscopic mechanical properties of coordinatively cross-linked polymer networks[J].Journal of the American Chemical Society,2005,127(41):14488-14496.
[5]LOVELESS D M,AND S L J,CRAIG S L.Rational control of viscoelastic properties in multicomponent associative polymer networks[J].Macromolecules,2005,38(24):10171-10177.
[6]YOUNT W C,LOVELESS D M,CRAIG S L.Strong means slow:Dynamic contributions to the bulk mechanical properties of supramolecular networks[J].Angewandte Chemie,2005,44(18):2746-2748.
[7]王亮,郭成功,王彩旗.基于β-环糊精和二茂铁主客体作用的超分子聚合物的制备及其凝胶化[J].功能高分子学报,2012,25(4):335-341.
[8]LIAO X,CHEN G,LIU X,et al.Photoresponsive pseudopolyrotaxane hydrogels based on competition of host-guest interactions[J].Angewandte Chemie,2010,49(26):4409-4413.
[9]SIMON K A,WARREN N J,MOSADEGH B,et al.Disulfide-based diblock copolymer worm gels:A wholly-synthetic thermo-reversible 3D matrix for sheet-based cultures[J].Biomacromolecules,2015,16(12):3952-3958.
[10]WEI C,CHEN M,LIU D,et al.A recyclable disulfide bond chemical cross-linking high toughness,high conductivity ion gels based on re-shaping and restructuring in gel state[J].Polymer Chemistry,2015,6(22):4067-4070.
[11]MUKHERJEE S,HILL M R,SUMERLIN B S.Self-healing hydrogels containing reversible oxime crosslinks[J].Soft Matter,2015,11(30):6152-6161.
[12]COLLINS J,NADGORNY M,XIAO Z,et al.Doubly dynamic self-healing materials based on oxime click chemistry and boronic acids[J].Macromolecular Rapid Communications,2017,38(6):1600760.
[13]吕展,郭赞如,贺站锋,等.基于酰腙可逆共价键制备溶胶-凝胶转变的可自愈合水凝胶[J].功能高分子学报,2015,28(4):373-379.
[14]CHAO A,NEGULESCU I,ZHANG D.Dynamic covalent polymer networks based on degenerative imine bond exchange:Tuning the malleability and self-healing properties by solvent[J].Macromolecules,2016,49(17):6277-6284.
[15]MURPHY E B,WUDL F.The world of smart healable materials[J].Progress in Polymer Science,2010,35(1):223-251.
[16]SIJBESMA R P,MEIJER E W.Reversible polymers formed from self-complementary monomers using quadruple hydrogen bonding[J].Science,1997,278(5343):1601-1604.
[17]CORDIER P,TOURNIHAC F,SOULI-ZIAKOVIC C,et al.Self-healing and thermoreversible rubber from supramolecular assembly[J].Nature,2008,451(7181):977-980.
[18]TAYLOR D L,IN H P M.Self-healing hydrogels[J].Advanced Materials,2016,28(41):9060-9093.
[19]LU W,LE X,ZHANG J,et al.Supramolecular shape memory hydrogels:A new bridge between stimuli-responsive polymers and supramolecular chemistry[J].Chemical Society Reviews,2017,46(5):1284-1294.
[20]LI J,VIVEROS J,WRUE M,et al.Shape-memory effects in polymer networks containing reversibly associating sidegroups[J].Advanced Materials,2010,19(19):2851-2855.
[21]BINDER W H,PETRARU L,ROTH T,et al.Magnetic and temperature-sensitive release gels from supramolecular polymers[J].Advanced Functional Materials,2010,17(8):1317-1326.
[22]KAMALY N,YAMEEN B,WU J,et al.Degradable controlled-release polymers and polymeric nanoparticles:Mechanisms of controlling drug release[J].Chemical Reviews,2016,116(4):2602-2663.
[23]RUBINSTEIN M,SEMENOV A N.Dynamics of entangled solutions of associating polymers[J].Macromolecules,2001,34(4):1058-1068.
[24]RUBINSTEIN M,DOBRYNIN A V.Solutions of associative polymers[J].Trend in Polymer Science,1997,5(6):181-186.
[25]MARRUCCI G,BHARGAVA S,COOPER S L.Models of shear-thickening behavior in physically crosslinked networks[J].Macromolecules,1993,26(26):6483-6488.
[26]XU D,CRAIG S L.Multiple dynamic processes contribute to the complex steady shear behavior of cross-linked supramolecular networks of semidilute entangled polymer solutions[J].Journal of Physical Chemistry Letters,2010,1(11):1683-1686.
[27]XU D,CRAIG S L.Scaling laws in supramolecular polymer networks[J].Macromolecules,2011,44(13):5465-5472.
[28]XU D,CRAIG S L.Strain hardening and strain softening of reversibly cross-linked supramolecular polymer networks[J].Macromolecules,2011,44(18):7478-7488.
[29]XU D,HAWK J L,LOVELESS D M,et al.Mechanism of shear thickening in reversibly cross-linked supramolecular polymer networks[J].Macromolecules,2010,43(7):3556-3565.
[30]XU D,LIU C Y,CRAIG S L.Divergent shear thinning and shear thickening behavior of supramolecular polymer networks in semidilute entangled polymer solutions[J].Macromolecules,2011,44(7):2343-2353.
[31]JIN L,TAN Y,SHANGGUAN Y,et al.Multiregion shear thinning for subsequent static self-thickening in chitosangraft-polyacrylamide aqueous solution[J].Journal of Physical Chemistry B,2013,117(48):15111-15121.
[32]JIN L,SHANGGUAN Y,YE T,et al.Shear induced self-thickening in chitosan-grafted polyacrylamide aqueous solution[J].Soft Matter,2013,9(6):1835-1843.
[33]CHOH S Y,CROSS D,WANG C.Facile synthesis and characterization of disulfide-cross-linked hyaluronic acid hydrogels for protein delivery and cell encapsulation[J].Biomacromolecules,2011,12(4):1126-1136.
[34]YANG Q,WANG P,ZHAO C,et al.Light-switchable self-healing hydrogel based on host-guest macro-crosslinking[J].Macromolecular Rapid Communications,2017,38(6):1600741.
[35]ZHANG Y,TAO L,SHUXI L,et al.Synthesis of multiresponsive and dynamic chitosan-based hydrogels for controlled release of bioactive molecules[J].Biomacromolecules,2011,12(8):2894-2901.
[36]FERRY J D.Viscoelastic Properties of Polymers[M].New Jerssy:John Wiley&Sons,1980.
[37]RUBINSTEIN M,COLBY,R H.Polymer Physics[M].New York:Oxford University Press,2003.
[38]LEIBLER L,RUBINSTEIN M,COLBY R H.Dynamics of reversible networks[J].Macromolecules,1991,24(16):4701-4707.
[39]YANG H,YU K,MU X,et al.A molecular dynamics study of bond exchange reactions in covalent adaptable networks[J].Soft Matter,2015,11(31):6305-6317.
[40]GROOT R D,AGTEROF W G M.Dynamic viscoelastic modulus of associative polymer networks:Off-lattice simulations,theory and comparison to experiments[J].Macromolecules,1995,28(18):6284-6295.
[41]NG W K,TAM K C,JENKINS R D.Lifetime and network relaxation time of a HEUR-C20associative polymer system[J].Journal of Rheology,2000,44(44):137-147.
[42]AND Y U,MACDONALD P M.NMR diffusion and relaxation time studies of HEUR associating polymer binding to polystyrene latex[J].Macromolecules,1995,29(1):63-69.
[43]GONZ LEZ A E.Viscosity of ionomer gels[J].Polymer,1983,24(1):77-80.
[44]GONZ LEZ A E.Viscoelasticity of ionomer gels:2.The elastic moduli[J].Polymer,1984,25(10):1469-1474.
[45]HUANG G,ZHANG H,LIU Y,et al.Strain hardening behavior of poly(vinyl alcohol)/borate hydrogels[J].Macromolecules,2017,50(5):2124-2135.