Biocompatibility tensile test

In contrast to PPSu which is a new polyester, PCL is well-known and extensively studied polymer. It is also biocompatible and has found many applications in pharmaceutical technology and medicine. Thus, it was also an interesting idea to explore miscibility and biodegradation behavior of blends made of these two very important polyesters. PCL/PPSu blends with concentrations 90/10, 80/20, 70/30 and 60/40 w/w were prepared by solutioncasting [47]. Proper amounts of both polymers were dissolved in chloroform as common solvent, at room temperature. Sonication was applied in order to achieve complete dissolution and fine mixing of the components. The blends in the form of thin films (200-250 pm) were set up after solvent evaporation at room temperature, under a gentle air stream. They were characterized by DSC, WAXD, HNMR, SEM, and Tensile testing. Finally, their enzymatic hydrolysis was studied. The PCL/PPSu blend system however proved to be only partially... 

Various tests and analytical methods are used for the characterisation and evaluation of the properties of vegetable oil-based polymer composites. Mechanical tests for properties such as tensile, flexural, compressive, impact, hardness and wear are carried out by a universal testing machine (UTM), and by equipment for testing impact, hardness, abrasion loss, and so on. Weather and chemical resistance tests are performed in UV/ozone, an artificial environmental chamber and in different chemical media. Water uptake and biodegradability tests are carried out by standard ASTM methods. Biodegradability and biocompatibility may be studied by the same procedure as described in Chapter 2. However, in practice only a few such studies have been performed for vegetable oil-based composites. 

Equivalency can be established through a series of data. Replacement materials can be compared with the original material in terms of chemical (structure, molecular weight, thermal properties, etc.) and mechanical properties (strength, tensile modulus, endurance, etc.). Data from actual devices fabricated from the new material should be compared with those from the original device. Biocompatibility data may be available from the material manufacturer, although the agency will request that additional data be supplied if the process used to fabricate the test samples differs from the process used to fabricate the device. 

Zhijiang et al. reported an improvement in the mechanical properties of a PHB nanocomposite made of bacterial cellulose nanofibrils that was prepared by the solution casting method. In addition, they found that the nanocomposite showed better biocompatibility and mechanical properties than pure PHB based on cell-adhesion analysis using Chinese hamster lung (CHL) fibroblast cells and stress strain tests, respectively. In comparison to pure PHB, the nanocomposite of PHB/bacterial cellulose was observed to exhibit about a 202% increase in tensile stress and a 2.2-fold increase in elongation to break, respectively (Figure 5.3). ... 

---