Investigation of mechanical properties and the effect of volume fraction of polyacrylamide hydrogel with molecular dynamics simulation

Hydrogels use three-dimensional polymer networks with transverse connections as their technology to absorb water or biofluids. Water, as a fundamental component, significantly affects the functionality of biomedical polymers, including hydrogels. The molecular organization of water within hydrogels and its state (limited, medium, or free) were significant factors in biocompatibility and compatibility. If hydrophilic monomers are directly used to produce the product, the manufactured product will have poor mechanical properties. Consequently, it is critical to conduct research on the mechanical properties of hydrogels, as well as methods for increasing them. This study examined the interactions between polyacrylamide hydrogel and water molecules by studying the effect of different volume fractions (5-15 %) of polyacrylamide hydrogel on the mechanical properties (Young's modulus and ultimate strength) using molecular dynamics simulation. The results show that the potential and total energy in the sample converged to -43 and 12488 kcal/mol. The ultimate strength of sample was 0.0333 MPa. The Young's modulus calculated for polyacrylamide was 0.0009 MPa. By increasing the atomic ratio of structure in the range of 5 % to 15 %, the ultimate strength value increased from 0.0333 MPa to 0.0425 MPa. The value of Young's modulus reached its maximum, from 0.0009 MPa to 0.0014 MPa.