Poly(lactic acid)

7 Chapter 6 FIGURE 6.1 Sample preparations and phase transitions of the various crystal ... FIGURE 6.2 2D‐WAXD patterns of PLLA (a) mesophase, (b) δform, (c) α... FIGURE 6.3 Crystal structure of PLLA α form. The space group is P 12 11. No sy... FIGURE 6.4 Comparison between the observed (broken line) and calculated (sol... FIGURE 6.5 (a) Comparison of the observed 00 l reflection profile with the ca... FIGURE 6.6 Temperature dependence of the 1D WAXD profile measured in the pha... FIGURE 6.7 Observed X‐ray 00 l reflection profiles of PLLA αand δ... FIGURE 6.8 Crystal structure of PLLA βform (model 2). FIGURE 6.9 Comparison of the observed X‐ray diffraction profiles with those ... FIGURE 6.10 Temperature dependence of 2D X‐ray diffraction patterns of the o... FIGURE 6.11 The temperature dependence of the crystallite size estimated for... FIGURE 6.12 (a) and (b) Time dependence of normalized intensity of the cryst... FIGURE 6.13 The 2D WAXD patterns measured at 25°C for the uniaxially oriente... FIGURE 6.14 Temperature dependence of 2D X‐ray diffraction pattern of highly... FIGURE 6.15 (a) Comparison of the unit cell ab ‐plane structure between the α... FIGURE 6.16 (a) and (b) Various chain packing modes of PLA stereocomplex wit... FIGURE 6.17 Temperature dependence of X‐ray diffraction profiles of the solu... FIGURE 6.18 2‐Dimensional X‐ray diffraction diagrams of the uniaxially orien... FIGURE 6.19 Crystal structure of PLLA (L)/PDLA (R) stereocomplex. One lattic... FIGURE 6.20 (a) Comparison of the observed X‐ray diffraction profiles along ... FIGURE 6.21 (a) IR circular dichroism ΔAbs and IR spectra measured for ... FIGURE 6.22 A model of stereocomplex formation from the solution cast L/D bl... FIGURE 6.23 (a) Chain conformation and (b) chain packing mode obtained for t... FIGURE 6.24 The 2D X‐ray diffraction patterns of PHB. (a) The mixture of the... FIGURE 6.25 (a) Images of the higher‐order structure of the αand β... FIGURE 6.26 (a) (A) polarized optical microscopic image and (B) and (C) SEM ...

8 Chapter 7 FIGURE 7.1 Percent transmission versus wavelength for PLA (98% L‐lactide), P... FIGURE 7.2 Index of refraction for PLA as a function of wavelength from a gl... FIGURE 7.3 Infrared spectra of poly(L‐lactic acid)s: PLA 100 (semicrystallin... FIGURE 7.4 Infrared spectra of semicrystalline 98 : 2 (L : D)poly(lactic aci... FIGURE 7.5 Infrared spectra of amorphous 80 : 20 (L : D)poly(lactic acid) [4... FIGURE 7.6 Infrared spectra of L‐crystalline (L‐C), L‐amorphous (L‐A), and r... FIGURE 7.7 VSFG spectra of the delocalized modes of L‐crystalline (L‐C), L‐a... FIGURE 7.8 FTIR spectra (a) and corresponding second derivatives (b) in the ... FIGURE 7.9 Raman spectra of poly(L‐lactic acid)s: PLA 100 (semicrystalline),... FIGURE 7.10 Raman spectrum of a 4.1% D‐PLA unoriented cast film. FIGURE 7.11 Raman spectrum of a 4.1% D‐PLA‐oriented cast film. FIGURE 7.12 Diagram illustrating the alternative interpretation of 1H and 13 FIGURE 7.13 1H and 13C solution NMR spectra of PLA synthesized using 5% L‐la... FIGURE 7.14 13C NMR spectra of PLA synthesized using (a) 5% fully 13C‐labele... FIGURE 7.15 (a) Methine resonances in the 13C NMR spectra of poly(lactide) s...

9 Chapter 8FIGURE 8.1 Differential scanning calorimetry thermograms of amorphous PLLA a...FIGURE 8.2 DSC thermal cycles of PLLA 200 kDa (first heating, cooling, and s...FIGURE 8.3 Effect of annealing time on crystallinity of compression‐molded P...FIGURE 8.4 T mof PLLA (▾) and T gof PLLA (•) and PDLLA (⚬) polymer as a func...FIGURE 8.5 Storage modulus E′, loss modulus E″, and damping tan δ of PDLLA. ...FIGURE 8.6 Storage modulus E′, loss modulus E″, and damping tan δ of PLLA wi...FIGURE 8.7 Effect of crystallinity on the intensity of the transition S of c...FIGURE 8.8 Storage modulus E ′ and damping factor tan δ of PLLA samples at va...FIGURE 8.9 Height (▵) and width (▾) of damping peak of PLLA as a function of...FIGURE 8.10 Radius growth rate G as function of crystallization temperature FIGURE 8.11 Crystallinity of melt‐spun PLLA fiber drawn at 160°C (⚬) and cry...FIGURE 8.12 DSC curves of melt‐spun PLLA fibers collected at different rates...FIGURE 8.13 First and second DSC scans of as‐spun PLLA fibers produced by so...FIGURE 8.14 DSC thermograms of solution‐spun fibers after drawing at various...FIGURE 8.15 Effect of composition on T g, T m(a), and crystallinity (b) of L‐...FIGURE 8.16 T gand T mof poly‐L‐D,L‐lactide as a function of D,L‐lactide con...FIGURE 8.17 DSC thermograms of selected commercial pellets (a), PLA products...FIGURE 8.18 Crystallinity percentage (▵, ▴) and molecular weight (⚪, ⚫) as a...

10 Chapter 9FIGURE 9.1 Stockmayer–Fixman plots, reconstructed from published Mark–Houwin...FIGURE 9.2 Stockmayer–Fixman plots for three separate solvents from the stud...FIGURE 9.3 Stereochemistry of L, D, and D,L‐PLA backbones.FIGURE 9.4 Element undergoing shear deformation due to an applied force.FIGURE 9.5 Effect of changing the zero shear viscosity parameter in the HN m...FIGURE 9.6 Effect of changing the characteristic time parameter in the HN mo...FIGURE 9.7 Effect of changing α, the breadth parameter, in the HN model.FIGURE 9.8 Effect of changing the high‐frequency ν parameter in the HN model...FIGURE 9.9 Master curves for an amorphous PLA sample with a weight‐average m...FIGURE 9.10 Scaling of the zero shear viscosity against molecular weight for...

11 Chapter 10FIGURE 10.1 Dynamic mechanical spectrum of poly(L‐lactic acid) Resomer L 214...FIGURE 10.2 Influence of aging on the dynamic mechanical spectrum of PLLA. A...FIGURE 10.3 Polarizing micrographs of crack behavior of PLA: (a) quenched st...FIGURE 10.4 Polarized micrographs of PLLA annealed microstructures: (a) 70°C...FIGURE 10.5 Tensile stress‐stain behavior of neat PLA compared with that of ...FIGURE 10.6 Brittle fracture of amorphous PLA: (a) specimen before deformati...FIGURE 10.7 Stress–strain curves for blend film and nonblended PLLA film. Th...FIGURE 10.8 Representative polarizing microscopic photographs of 1 : 1 PLLA:...FIGURE 10.9 (a) Storage modulus curves as a function of temperature from DMA...FIGURE 10.10 Tensile mechanical properties of TPS/PLA (70w/30w) blends with ...FIGURE 10.11 The processing‐morphology‐tensile properties relationship of PL...FIGURE 10.12 (a) Elongation at break, (b) impact strength, (c) tensile stren...

12 Chapter 11FIGURE 11.1 Comparisons of permeability coefficients ( P ) of O 2, CO 2, and N 2...FIGURE 11.2 Permeation of permeant molecules from a higher to a lower chemic...FIGURE 11.3 Arrhenius plot of permeability coefficients ( P ) of O 2, CO 2, N 2, ...FIGURE 11.4 Arrhenius plots of diffusion coefficients ( D ) for O 2, CO 2, N 2, a...FIGURE 11.5 Arrhenius plots of solubility coefficients ( S ) for O 2, CO 2, N 2, ...FIGURE 11.6 Permeability coefficients of oxygen ( ) in PLA films between 5 ...FIGURE 11.7 (a–c) , , and measured at 23°C and 0% RH shown in origina...FIGURE 11.8 Arrhenius plots of water vapor permeability coefficients ( ) in...FIGURE 11.9 P of different volatile organic compounds in PLA films grouped b...FIGURE 11.10 Correlation between the molecular volume of the permeants and t...FIGURE 11.11 Gas permeabilities of PLA and PLA/organoclay (Cloisite 30B) wit...