Study of the Crosslinking of PHEMA Hydrogels by FTIR for Biomedical Applications

摘要

The spectrum of figure 1 shows that vinyl groups are consumed during the polymerization reaction and curing of HEMA simultaneous. It is seen that the relative intensity of the bands C = C decreases with increase in weight rate HEMA / water. This can be explained by the crosslinking agent DEGDMA. Although this concentration was kept constant at the beginning of the reaction, during the preparation of raw material HEMA may be present DEGDMA as a by-product of the reaction. Thus, insofar as it increases the amount of HEMA, there may be variation in the DEGDMA concentration in reaction medium, which acts as a healer, facilitates networking by reducing the rate of termination of life of free radicals. However, in the concentration of 40 percent to 60% by mass of HEMA the reaction mechanism is changed. When the reaction conversion increases due to higher fraction of DEGDMA, the density of the matrix increases, the monomers are trapped in this and the vinyl groups are prevented from reacting. The diffusional resistance, therefore, becomes at this concentration, the predominant mechanism. (Huang, C-W. J.Wiley, Inc. 1996; 1873-1888). This result is therefore of paramount importance in the interpretation and synthesis of PHEMA substrates for cell culture, and view their final properties.