Silane-Treated E-Glass Fiber-Reinforced Telechelic Macromer-Based Polymer-Matrix Composites

: Puska M, Zhang M, Matinlinna JP, Vallittu PK

Publisher: SPRINGER

: 2014

: Silicon

: SILICON

: SILICON-NETH

: 6

: 1

: 57

: 63

: 7

: 1876-990X

: 1876-9918

DOI: https://doi.org/10.1007/s12633-013-9155-1

The aim of this in vitro study was to investigate the water sorption and flexural properties of fiber reinforced composites (FRC) prepared from telechelic macromer extended urethane dimethacrylate (PEG-400-E-UEDMA)(PEG), hydroxypropyl methacrylate (HPMA) and E-glass fibers. Three experimental groups of test specimens based on poly(PEG-400-E-UEDMA-HPMA) polymer matrices and continuous unidirectional E-glass fibers were light polymerized and stored in deionized water for 0, 4, 12 or 24 weeks. The weight ratios (%) of PEG-HPMA were 27.5-70.5, 49.0-49.0 and 70.5-27.5 with an initiator-activator percentage of 1.0-1.0. After each time period of storage the water absorption and flexural properties were measured. There were six test specimens in each of the test groups (N = 6) and the specimen's fracture surfaces were analyzed using scanning electron microscopy (SEM). All the PEG-HPMA groups exhibited the highest water absorption at the time point of two days (5.5 to 6.4 %), which thereafter decreased to the level of 3.8-4.7 % at the time point of 30 days. The flexural strength varied from dry specimens' 128 to 283 MPa to the 30 days water-stored specimens' of 30 to 49 MPa. The flexural modulus exhibited values from 7.9 to 14.8 GPa (dry specimens) and ca. 0.5 to 1.8 GPa after 30 days of water-storage. Both the flexural strength and modulus decrease dramatically with a longer water storage time. The SEM images showed good adhesion between the fibers and the resin matrix. In the wet conditions, the telechelic macromer based hydrophilic PEG polymer-matrix FRCs formed a plasticized composite that decreased the flexural properties.