Synthesis and charaacterization of new hydrogels through copolymerization of N-acryloyl-tris-(hydroxymethyl)aminomethane and different crosslinking agents

JULIO CUGGINO; CECILIA ALVAREZ I.; JUAN CARLOS RUEDA; LIDIA QUINZANI; HARTMUT KOMBER; MIRIAM STRUMIA

EUROPEAN POLYMER JOURNAL

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2008 p. 3548 - 3555

0014-3057

In this study, new hydrogels in rod shape were prepared from N-acryloyl-tris-(hydroxymethyl) aminomethane (NAT) using three different crosslinking agents: poly(2-methyl-2- oxazoline) bismacromonomer (BM), ethylene glycol dimethacrylate (EGDMA) and N,N0- methylenebisacrylamide (BIS). Dimethylformamide (DMF) was used as solvent and 2,20-azobisisobutyronitrile (AIBN) as initiator. Polymeric matrices with different properties were obtained by free radical polymerization by changing the crosslinker (BM, EGDMA or BIS) or the concentration of BM. The hydrogel structures were characterized by high resolution magic angle spinning (HRMAS) NMR technique. Swelling experiments and rheological studieswereusedto test thewater absorptioncapacityandviscoelasticproperties of thehydrogels, respectively.For agivenNAT/crosslinkingagentmolar ratio, thehydrogel synthesizedwith BM displays higher water absorptive capacity and larger range of linear viscoelasticity than those synthesized with BIS or EGDMA. The relatively larger hydrophilic character of the former and the lower crosslinking density generated by the longermolecules ofBMmight be the cause of this behavior.The results also reveal thatwater diffuses into the network followinganon-Fickian mechanism. This is concluded fromthe value of the diffusion exponent n, which is higher than 0.50. The elastic modulus and the equilibrium water content (EWC) measurements suggest that these materials may have potential application as biomaterials.N-acryloyl-tris-(hydroxymethyl) aminomethane (NAT) using three different crosslinking agents: poly(2-methyl-2- oxazoline) bismacromonomer (BM), ethylene glycol dimethacrylate (EGDMA) and N,N0- methylenebisacrylamide (BIS). Dimethylformamide (DMF) was used as solvent and 2,20-azobisisobutyronitrile (AIBN) as initiator. Polymeric matrices with different properties were obtained by free radical polymerization by changing the crosslinker (BM, EGDMA or BIS) or the concentration of BM. The hydrogel structures were characterized by high resolution magic angle spinning (HRMAS) NMR technique. Swelling experiments and rheological studieswereusedto test thewater absorptioncapacityandviscoelasticproperties of thehydrogels, respectively.For agivenNAT/crosslinkingagentmolar ratio, thehydrogel synthesizedwith BM displays higher water absorptive capacity and larger range of linear viscoelasticity than those synthesized with BIS or EGDMA. The relatively larger hydrophilic character of the former and the lower crosslinking density generated by the longermolecules ofBMmight be the cause of this behavior.The results also reveal thatwater diffuses into the network followinganon-Fickian mechanism. This is concluded fromthe value of the diffusion exponent n, which is higher than 0.50. The elastic modulus and the equilibrium water content (EWC) measurements suggest that these materials may have potential application as biomaterials.N,N0- methylenebisacrylamide (BIS). Dimethylformamide (DMF) was used as solvent and 2,20-azobisisobutyronitrile (AIBN) as initiator. Polymeric matrices with different properties were obtained by free radical polymerization by changing the crosslinker (BM, EGDMA or BIS) or the concentration of BM. The hydrogel structures were characterized by high resolution magic angle spinning (HRMAS) NMR technique. Swelling experiments and rheological studieswereusedto test thewater absorptioncapacityandviscoelasticproperties of thehydrogels, respectively.For agivenNAT/crosslinkingagentmolar ratio, thehydrogel synthesizedwith BM displays higher water absorptive capacity and larger range of linear viscoelasticity than those synthesized with BIS or EGDMA. The relatively larger hydrophilic character of the former and the lower crosslinking density generated by the longermolecules ofBMmight be the cause of this behavior.The results also reveal thatwater diffuses into the network followinganon-Fickian mechanism. This is concluded fromthe value of the diffusion exponent n, which is higher than 0.50. The elastic modulus and the equilibrium water content (EWC) measurements suggest that these materials may have potential application as biomaterials.0-azobisisobutyronitrile (AIBN) as initiator. Polymeric matrices with different properties were obtained by free radical polymerization by changing the crosslinker (BM, EGDMA or BIS) or the concentration of BM. The hydrogel structures were characterized by high resolution magic angle spinning (HRMAS) NMR technique. Swelling experiments and rheological studieswereusedto test thewater absorptioncapacityandviscoelasticproperties of thehydrogels, respectively.For agivenNAT/crosslinkingagentmolar ratio, thehydrogel synthesizedwith BM displays higher water absorptive capacity and larger range of linear viscoelasticity than those synthesized with BIS or EGDMA. The relatively larger hydrophilic character of the former and the lower crosslinking density generated by the longermolecules ofBMmight be the cause of this behavior.The results also reveal thatwater diffuses into the network followinganon-Fickian mechanism. This is concluded fromthe value of the diffusion exponent n, which is higher than 0.50. The elastic modulus and the equilibrium water content (EWC) measurements suggest that these materials may have potential application as biomaterials.n, which is higher than 0.50. The elastic modulus and the equilibrium water content (EWC) measurements suggest that these materials may have potential application as biomaterials.