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Glass Filler (glass + filler)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Tailoring Cell Behavior on Polymers by the Incorporation of Titanium Doped Phosphate Glass Filler,

ADVANCED ENGINEERING MATERIALS, Issue 7 2010
Wojciech Chrzanowski
Abstract Understanding tissue response to materials, to enable modulation and guided tissue regeneration is one of the main challenges in biomaterials science. Nowadays polymers, glasses, and metals dominate as biomaterials. Often native properties of those materials are not sufficient and there is a need to combine them, so as to modify and adjust their properties to the application. The primary aim of this study was to improve cell response to polymer (PLDL) using phosphate glass as filler (titanium doped phosphate glass). As a control ,-tricalcium phosphate (TCP) filler was used. Various concentrations of the filler were used (10,40 vol%). Wetting behavior, , -potentials, mechanical and thermal properties, and human cells response to the materials were evaluated. Results showed that with increase in glass filler loading wettability improved, , -potentials dropped, and increase in stiffness of materials was observed. Importantly cell culture experiments showed more developed and well spread cells on the samples with glass content up to 20 vol%. Cells responded much more positively to the glass filled samples than to TCP filled. However, expression of osteocalcin and osteopontin, proteins that indicate formation of the mineralized structures was positive for all the samples including pure PLDL. It was concluded that due to improved wetting behavior, lower , -potentials, and specific chemistry of the glass filler it was possible to alter cells response, improve bioactivity of the polymer, and vary mechanical properties. [source]

Hyperbranched polyesters and their application in dental composites: monomers for low shrinking composites

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2001
J. E. Klee
Abstract Using trimethylolpropane (TMP) and 2,2-bishydroxymethylpropionic acid (Bis-MPA), aliphatic hyperbranched polyesters (HBP) were synthesized, with a degree of branching of DB,=,0.47 and a degree of polymerization of Pn,=,16.5. Aromatic HBPs with repetitive units of 2,2-bis(4-hydroxyphenyl)pivalonic acid (Bis-PVA) lead to a higher DB,=,0.48 and Pn,=,30.5 compared to the aliphatic HBP. Reactive functionalization of the hyperbranched polymers was achieved via esterification of mixtures of methacrylic acid and carboxylic acids. In this manner, i -butyric acid and methacryloyl terminated HBPs were obtained. They have a low viscosity ranging from 200 to 364,Pa*s and exhibit relatively low volume shrinkage (1.9 to 3.6%) during photoinitiated cure. Dental composites with volume shrinkage of 0.5 to 1.5% have been prepared using these methacryloyl terminated HBPs in combination with a Ba/alumosilicate glass filler. Copyright © 2001 John Wiley & Sons, Ltd. [source]

The effect of interface characteristics on the static and dynamic mechanical properties of three-component polymer alloys

POLYMER COMPOSITES, Issue 3 2002
I. Fisher
The effect of interfacial characteristics on the structure-property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene-vinyl alcohol copolymer (EVOH) and glass beads (GB) or fibers (GF) was investigated. The systems studied were based on a binary PP/EVOH immiscible blend, representing a blend of a semi-crystalline apolar polymer with a semi-crystalline highly polar copolymer. The ternary systems studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfacial properties was done using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA-g-PP) for the PP/EVOH interface. Both glass fillers increased the dynamic modulus and decreased the damping of the neat polymers and of their binary blends, especially in the rubbery region. GF has a more profound effect on both the modulus and the damping. Glass surface treatments and compatibilization have only a marginal effect on the dynamic mechanical behavior of the ternary blends. Yet, compatibilization shifted the polymers' TgS to higher temperatures. Both glass fillers increased the elastic modulus of the binary blends, where GF performed better than GB as a reinforcing agent. GF slightly increased the strength of the binary blends while, GB reduced it. Both fillers reduced the ductility of the binary blends. The blends' mechanical properties were related to the morphology and their components' crystallinity. The compatibilizer increases both stiffness and strength and reduces deformability. [source]