Influence of the Processes Parameters on the Properties of The ...

Chapter 4.
Experimental Procedures and Protocols for Analyses
just after <strong>the</strong> initial linear portion, elastic region, <strong>of</strong> <strong>the</strong> stress-strain curve. (cf. Figure 4.31). The
compressive modulus was defined as <strong>the</strong> initial linear modulus. The compressive strength ( ) was
estimated by determining <strong>the</strong> stress at 10% deformation.
6 Conclusion
Figure 4.31: Stress strain graph <strong>of</strong> PLGA foam obtained showing <strong>the</strong> three regions.
In this chapter, all <strong>the</strong> experimental procedures and <strong>the</strong>ir limitations have been discussed in detail
with respect to <strong>the</strong> equipment used for <strong>the</strong> experimentation. For size reduction <strong>of</strong> <strong>the</strong> polymeric granulates or
fibres we introduced knife mill, tumbling ball mill and mortar used in our studies. The procedures to make
pellets by dry method using <strong>the</strong> hydraullic press and wet method preparation has been described. Two
different types <strong>of</strong> supercritical fluid equipment were under utilization to produce biopolymer foams. One <strong>of</strong>
<strong>the</strong> equipment was bound for limited number <strong>of</strong> foams per batch due to low chamber volume while o<strong>the</strong>r
was used to process foams in semi-industrial quantities. We <strong>the</strong>n presented <strong>the</strong> various protocols <strong>of</strong> analysis
techniques for characterizing <strong>the</strong> physicochemical and use properties <strong>of</strong> initial, ground and co-ground
products such as granulometry for particle size and <strong>the</strong>ir distribution.
Analytical techniques such as differential scanning calorimetry for glass transition temperature
and o<strong>the</strong>r <strong>the</strong>rmal properties, sieving for powder gradation, mixing <strong>of</strong> materials for homogenization, SEM
for size morphology, geometric and Hg intrusion porosimetry for pore size and distribution and contact
angle for surface properties were discussed. SCION ® image analysis technique has been explained with an
example to calculate <strong>the</strong> number or pores, pore distribution and types <strong>of</strong> pores. Then micro-CT protocol for
<strong>the</strong> structural assessment <strong>of</strong> polymer foam and to elaborate <strong>the</strong> interconnectivity has been presented. Finally,
mechanical properties <strong>of</strong> <strong>the</strong> polymer by using Brazilian testing and compression testing <strong>of</strong> <strong>the</strong> foamed
product are elaborated.
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