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

More documents

Recommendations

Info

Figure 4.28: Incremental Intrusion vs Pore size. ........................................................................................... 108 Figure 4.29: Set up <strong>of</strong> CT and Flow chart <strong>of</strong> CT measurement process. .................................................. 109 Figure 4.30: CT slice view from different direction for different bone scaffold presenting <strong>the</strong> interconnectivity. ....................................................................................................................... 110 Figure 4.31: Stress strain graph <strong>of</strong> PLGA foam obtained showing <strong>the</strong> three regions. .................................. 111 Figure 5.1: Courbe size distribution <strong>of</strong> various PLAs after knife mill grinding. ........................................... 115 Figure 5.2: Thermograms <strong>of</strong> various PLAs. .................................................................................................. 116 Figure 5.3: Thermograms <strong>of</strong> PLGA 50:50 . ........................................................................................................ 117 Figure 5.4: Thermograms <strong>of</strong> 3 different PLGA 85:15 . ...................................................................................... 117 Figure 5.5: Stress strain curve obtained from Brazilian Test for P L,D LA (PAB RL 68). ............................... 119 Figure 5.6: (A)-Kinetics and modelling <strong>of</strong> <strong>the</strong> sorption <strong>of</strong> CO 2 in PLGA 50:50 at 125 bar and 36.5°C, (B) Desorption <strong>of</strong> CO 2 from PLGA 50:50 <strong>of</strong> CO 2 in PLGA 50:50 at 125 bars and 36.5°C. .................... 121 Figure 5.7: Desorption <strong>of</strong> CO 2 from PLGA 50:50 after 100 and 200 bars, at T sat = 36.5°C and t sat = 120 min. 122 Figure 5.8: Sorption iso<strong>the</strong>rm <strong>of</strong> CO 2 into PLGA 50:50. ................................................................................... 123 Figure 5.9: The depression <strong>of</strong> PLGA 50:50 T g as a function <strong>of</strong> <strong>the</strong> weight fraction <strong>of</strong> sorbed CO 2 : (♦) 100 bars; (●) 200 bars. ............................................................................................................................... 124 Figure 5.10: Micrographs <strong>of</strong> <strong>the</strong> P L,DL LA and PLGA 50:50 blend scaffolds. .................................................... 125 Figure 5.11: Average pore diameter <strong>of</strong> polymer blends as a function <strong>of</strong> P L,DL LA ratio. ............................... 125 Figure 5.12: Average pore diameter <strong>of</strong> polymer blends as a function <strong>of</strong> P L,DL LA ratio. ............................... 126 Figure 5.13: Average pore diameter as a function <strong>of</strong> PLGA 50:50 ratio in <strong>the</strong> PLGA 50:50 /PLGA 85:15 blends. .. 128 Figure 5.14: Variation <strong>of</strong> foam porosity. ....................................................................................................... 130 Figure 5.15: Average pore diameters <strong>of</strong> PLGA 50:50 scaffolds as a function <strong>of</strong> <strong>the</strong> process parameters. ........ 130 Figure 5.16: Micrographs <strong>of</strong> <strong>the</strong> cross-section <strong>of</strong> <strong>the</strong> foams processed at P = 125 bars. ............................... 131 Figure 5.17: Variation <strong>of</strong> <strong>the</strong> porosity <strong>of</strong> <strong>the</strong> foams as a function <strong>of</strong> depressurization rate. .......................... 132 Figure 5.18: <strong>Influence</strong> <strong>of</strong> dP/dt on <strong>the</strong> pore size <strong>of</strong> <strong>the</strong> foams processed at scCO 2 condition P sat = 100 bars, T sat = 36.5°C and t sat = 60 min. ................................................................................................... 133 Figure 5.19: (A) Variation <strong>of</strong> pore diameter <strong>of</strong> <strong>the</strong> PLGA 50:50 scaffolds as <strong>the</strong> function <strong>of</strong> P sat ; (B) Variation <strong>of</strong> <strong>the</strong> energy barrier for PLGA 50:50 -CO 2 system. ....................................................................... 134 Figure 5.20: T g -w diagram <strong>of</strong> <strong>the</strong> P L,D LA (---) and PLGA 50 : 50 (—); (●) and (♦), are <strong>the</strong> weight fraction <strong>of</strong> CO 2 in P L,D LA and PLGA 50:50 at 100 bars, respectively. The value for <strong>the</strong> weight fraction <strong>of</strong> P L,D LA at 100 bars and 35°C is taken from [Pini et al., 2008]. ................................................. 136 Figure 5.21: Micrographs <strong>of</strong> scaffolds processed at P sat = 200 bars; T sat = 36.5°C, t sat = 20 min. and dP/dt = 20 bar /s. ..................................................................................................................................... 137 Figure 5.22: Micrographs revealing <strong>the</strong> effect <strong>of</strong> P sat on pore size. ............................................................... 138 Figure 5.23: Micrographs revealing <strong>the</strong> effect <strong>of</strong> T sat on pore size. ............................................................... 138 Figure 5.24: Micrographs revealing <strong>the</strong> effect <strong>of</strong> t sat on pore size. ................................................................ 139 Figure 5.25: Micrographs revealing <strong>the</strong> effect <strong>of</strong> dP/dt and dT/dt on pore size. ........................................... 140 Figure 5.26: Representation <strong>of</strong> <strong>the</strong> effect <strong>of</strong> <strong>the</strong> geometry <strong>of</strong> <strong>the</strong> pressure chamber on <strong>the</strong> porous structure. ................................................................................................................................................... 140 Figure 5.27: Micrographs depicting coalescence and collapse <strong>of</strong> pores. ....................................................... 141 Figure 5.28: Porosity <strong>of</strong> PLGA 50:50 foams for pellets with different initial thickness. .................................. 142 Figure 5.29: Pore density <strong>of</strong> PLGA 50:50 foams with different initial pellet thickness. ................................... 142 Figure 5.30: PLGA 50:50 foams obtained with different initial pellet thicknesses. .......................................... 143 Figure 5.31: Different distribution <strong>of</strong> pores in PLGA 50:50 foams. .................................................................. 143 Figure 5.32: Variation in PLGA 50:50 foams geometric porosity for different process parameters. ................ 144 - xxiii -
Figure 5.33: Distribution <strong>of</strong> pores at different process condition. ................................................................. 145 Figure 5.34: Cell densities <strong>of</strong> pores produced at different process condition. ............................................... 145 Figure 5.35: Percentage <strong>of</strong> surface area for Distribution <strong>of</strong> Pores. ................................................................ 145 Figure 5.36: Effective pore diameter for each process parameter. ................................................................ 145 Figure 6.1: Micrographs <strong>of</strong> P L,D LA foams processed by wet and dry methods. ............................................ 149 Figure 6.2: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> P L,D LA foams. ...................... 150 Figure 6.3: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> porosity <strong>of</strong> P L,D LA foams. ............................. 150 Figure 6.4: Micrographs <strong>of</strong> P L,D LA foams processed by wet and dry methods. ............................................ 152 Figure 6.5: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> P L,D LA foams. ...................... 153 Figure 6.6: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> geometric porosity <strong>of</strong> P L,D LA foams. ............ 153 Figure 6.7: Micrographs <strong>of</strong> P L,DL LA foams processed by wet and dry methods. ........................................... 155 Figure 6.8: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> P L,DL LA foams. .................... 155 Figure 6.9: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> geometric porosity <strong>of</strong> P L,DL LA foams. .......... 156 Figure 6.10: Micrographs <strong>of</strong> P L,DL LA foams processed by wet and dry methods. ......................................... 158 Figure 6.11: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> P L,DL LA foams. .................. 158 Figure 6.12: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> porosity <strong>of</strong> P L,DL LA foams. ......................... 159 Figure 6.13: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> equivalent pore diameter and porosity <strong>of</strong> P L,D LA and P L,DL LA foams by wet and dry methods from initial Taguchi plan. ........................ 159 Figure 6.14: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> equivalent pore diameter and porosity <strong>of</strong> P L,D LA and P L,DL LA foams by wet and dry methods from complementary Taguchi plan. ........ 160 Figure 6.15: Micrographs <strong>of</strong> PLGA 50:50 foams processed by wet and dry methods. ..................................... 162 Figure 6.16: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> PLGA 50:50 foams. ............... 162 Figure 6.17: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> geometric porosity <strong>of</strong> PLGA 50:50 foams. ..... 163 Figure 6.18: Micrographs <strong>of</strong> PLGA 50:50 foams processed by wet and dry methods. ..................................... 165 Figure 6.19: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> PLGA 50:50 foams. ............... 165 Figure 6.20: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> porosity <strong>of</strong> PLGA 50:50 foams. ...................... 166 Figure 6.21: Micrographs <strong>of</strong> PLGA 85:15 foams processed by wet and dry methods. ..................................... 167 Figure 6.22: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> PLGA 85:15 foams. ............... 168 Figure 6.23: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> porosity <strong>of</strong> PLGA 85:15 foams ....................... 168 Figure 6.24: Micrographs <strong>of</strong> PLGA 85:15 foams processed by wet and dry methods. ..................................... 170 Figure 6.25: Average effect <strong>of</strong> each parameter on equivalent pore diameter <strong>of</strong> PLGA 85:15 foams. ............... 170 Figure 6.26: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> porosity <strong>of</strong> PLGA 85:15 foams. ...................... 171 Figure 6.27: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> equivalent pore diameter and porosity <strong>of</strong> PLGA 50:50 and PLGA 85:15 foams by wet and dry method for initial Taguchi plan. ..................... 172 Figure 6.28: Average effect <strong>of</strong> each parameter on variation <strong>of</strong> equivalent pore diameter and porosity <strong>of</strong> PLGA 50:50 and PLGA 85:15 foams for complementary Taguchi plan. ........................................... 173 Figure 6.29: PLGA 50:50 scaffold pore morphology with detail inside view obtained by dry method and foams processed at 50 o C-150 bars-25 min-6 bar/s. ............................................................................... 174 Figure 6.30: Pore Morphology <strong>of</strong> different types <strong>of</strong> scaffold processed by wet and dry methods. ............... 175 Figure 6.31: Comparison <strong>of</strong> pore morphology for PLAs and PLGAs foams processed at T sat = 50 o C, P sat = 100 bars, t sat = 20 min and dP/dt = 3 bar/s. ................................................................................. 176 Figure 6.32: Slice images <strong>of</strong> P L,D LA foams structure by CT analysis. ........................................................ 176 Figure 6.33: Slice images <strong>of</strong> P L,DL LA foams structure by CT analysis. ...................................................... 176 Figure 6.34: Slice images <strong>of</strong> PLGA 50:50 foam structure by CT analysis. ..................................................... 177 Figure 6.35: Slice images <strong>of</strong> PLGA 85:15 foam structure by CT analysis. ..................................................... 177 - xxiv -
Page 1 and 2: Institut National Polytechnique de
Page 4: iii Dedicated to My Fathe</
Page 7 and 8: pleased I was to work with all memb
Page 10 and 11: Publications and Conferences The wo
Page 12 and 13: Nomenclature and Abbreviations Abbr
Page 14: ρ p Pellet density Splitting (Bra
Page 17 and 18: Chapter 2 .........................
Page 19 and 20: 6.2.1 Surface Tensions of</
Page 21 and 22: 4.1 Effect of <str
Page 23 and 24: 3.2 Experiments on PLA/Waxes Scaffo
Page 26 and 27: List of Figures Fi
Page 30 and 31: Figure 6.36: Micrographs of
Page 32 and 33: Figure 8.32: Slice images o
Page 34 and 35: List of Tables Tab
Page 36 and 37: Table 8.1: Polymers with different
Page 38 and 39: iological performance. Biocompatibi
Page 40 and 41: Thesis Introduction Chapter 1 Chapt
Page 42 and 43: Chapter 1. Polylactide Based Bio-Ma
Page 64 and 65: Chapter 2. Processes</stron
Page 78 and 79:
Chapter 2. Processes</stron
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Chapter 3. Analytical Methods and D
Page 100 and 101:
Page 102 and 103:
. Chapter 3. Analytical Methods and
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Chapter 4. Experimental Procedures
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Chapter 5 - 112 -
Page 150 and 151:
Chapter 5. Characterization <strong
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
show all

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

Create successful ePaper yourself

Delete template?

Save as template?