The influence of poly(acrylic acid) molar mass and concentration on the properties of polyalkenoate cements - Part II Young's modulus and flexural strength
B. Fennell et Rg. Hill, The influence of poly(acrylic acid) molar mass and concentration on the properties of polyalkenoate cements - Part II Young's modulus and flexural strength, J MATER SCI, 36(21), 2001, pp. 5177-5183
The Young's modulus and flexural strength were determined for glass polyalk
enoate cements as a function of poly(acrylic acid), PAA molar mass, concent
ration, glass volume fraction and cement ageing time. The Young's modulus w
as independent of PAA molar mass. The Young's modulus increased dramaticall
y with the PAA concentration of the cement until concentrations greater tha
n 50% m/m were reached. The modulus increased with time for nearly all the
cements investigated consistent with a continuing ionic cross-linking proce
ss in the cement matrix. The modulus increased with an increase in the volu
me fraction of the higher modulus glass phase. Increasing the glass volume
fraction provides more surface area for acid attack resulting in a more cro
ss-linked polysalt matrix, as well as increasing the volume fraction of res
idual glass particles. Flexural strength was highly dependent on molar mass
of the PAA and its concentration. The molar mass dependence of the flexura
l strength was greatest at higher PAA concentrations. (C) 2001 Kluwer Acade
mic Publishers.