Mechanical properties, degradable

The mechanical properties, degradation, and surface characteristics of poly(diol citrates) could be controlled by choosing different diols and by controUing synthesis conditions such as cross-linking temperature and time, vacuum, and initial monomer molar ratio. 

Figure 14.15 for a quench temperature of 800°C shows that for pure MgO there is very severe mechanical property degradation at low values of R... 

Coherently, as expected for immiscible blends, Tg values measured by DSC show very small variations with respect to the pure components while the mechanical properties degrade with respect to neat sPS. In particular, for minimum polyolefin contents <40 wt%, uniaxial tensile tests revealed a decrease in Young s modulus, elongation at break and energy to break. For higher contents, a phase inversion of the morphology occurs and the blend properties approach progressively those of the pure polyolefins. 

Yuan Y et al (2008) Mechanical property, degradation rate, and bone cell growth of chitosan coated titanium influenced by degree of deacetylation of chitosan. J Biomed Mater Res B Appl Biomater 86(l) 245-252... 

Both of processes run spontaneous, and their competition (connected with the differences of the reacting particles nature and the various reaction conditions) is characterized by a ratio of the thermolysis and the M particles diffusion to the hot metal centers in a solid polymer matrix. If the big particles (i.e., big in relation to the distances between the chains, crystalline blocks, or polymer lattice points) are introduced in the system, the polymer structure and its physical and mechanical properties degrade. 

By adjusting postpolymerization temperature and cross-linking (curing) time, the mechanical properties, degradation profiles, and surface energies of the cross-linked polyester networks, POC can be tuned to fit a wide range of tissue engineering applications (see Table 16.2) [2,16-18,35,50-56]. An increase in postpolymerization temperature and cross-... 

Cortical bone exhibits mechanical property degradations characteristic of a damaging ma-... 

Pattin, C. A., Caler, W. E., and Carter, D. R. (19%), Cyclic mechanical property degradation during fatigue loading of cortical bone, J. Biomech. 29(l) 69-79. 

PTFE is most well known by the DuPont brand name Teflon. It is highly resistant to chemicals and wear. According to DuPont, its melting point is 327 °C, but its mechanical properties degrade above 260 °C. Therefore, PTFE allows for processing steps in the 250 °C range. 

R. Censi, T. Vermonden, H. Deschout, K. Braeckmans, P. di Martino, S.C. De Smedt, et al, Photopolymerized thermosensitive poly(HPMAlactate)-PEG-based hydrogels Effect of network design on mechanical properties, degradation, and release behavior. Biomacromolecules, 11, 2143-51,2010. 

The requirements for an implant material are determined by the respective application. The key properties of degradable biomaterials are their mechanical properties, degradation rate and behaviour, their functionality and their biocompatibility. For each application, a specific set of the properties mentioned is needed. With the growing number of potential applications, the number of required materials with specific combinations of properties is also increasing. As the variability of properties is limited for those... 

Susceptible to this kind of mechanisms are cast stainless steels, to a lesser extent weld metal and some Cr rich martensitic steels. Several research projects funded by the USNRC, EPRI, George Fisher Limited of Switzerland, and a consortium of Westinghouse, Framatome and EDF have evaluated mechanical property degradation which results from thermal ageing embrittlement in typical cast duplex stainless steel materials [5.3],... 

Acetyl cellulose already degrades at small radiation doses with a reduction of its mechanical properties. Degradation in a vacuum or in oxygen proceeds similarly. Figure 5.154. 

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