Structure and Properties of Chitosan/Poly-Lactic Acid Blend Scaffold and Chitosan Powder/Poly-Lactic Acid Blend Scaffold

2013 ◽  
Vol 647 ◽  
pp. 9-15
Author(s):  
Dan Ying Zuo ◽  
Hong Jun Li
Keyword(s):  
Lactic Acid ◽  
Cross Section ◽  
Poly Lactic Acid ◽  
Inversion Method ◽  
Plla Scaffold ◽  
The Difference ◽  
Phase Separation Behavior ◽  
Phase Inversion Method ◽  
Precipitation Phase ◽  
Chitosan Powder

The chitosan (CS) /poly-L-lactic (PLLA) acid blend scaffolds were prepared by two kinds of blend solutions through immersion precipitation phase inversion method. CS/PLLA blend scaffold was fabricated by mixing the CS-HAc solution and PLLA-DMF solution, CSP/PLLA blend scaffold was fabricated by mixing chitosan powder (CSP) and PLLA-DMF solution. The results revealed that CS content in CSP/PLLA scaffold was 126 times higher than that in CS/PLLA scaffold. The difference of CS content made the structures of CS/PLLA scaffold and CSP/PLLA scaffold exhibit an obvious discrepancy, which resulted from the different thermodynamics and phase separation behavior of two blend solutions. CS/PLLA scaffold with a higher porosity took on an unsymmetrical structure with a compact upper surface and a porous cross-section containing the fingerlike macrovoids, while CSP/PLLA scaffold displayed a symmetrical structure with a porous upper surface and the sponge-like cross-section. WVTR and equilibrium swelling of CSP/PLLA blend scaffold were higher than that of CS/PLLA blend scaffold. WAXD analysis revealed that PLLA and CS did not crystallize in the course of CS/PLLA scaffold formation, while there were the diffraction peaks of PLLA and CS in the CSP/PLLA scaffold.

Effect of Solvent Evaporation Time on CO2/CH4 Gas Performance for Poly(Lactic) Acid Membranes

2015 ◽  
Vol 1113 ◽  
pp. 660-666 ◽  
Author(s):  
Wahida Nor Rasyiada Jami’an ◽  
H. Hasbullah ◽  
Fadilah Mohamed ◽  
Ahmad Rashid Ahmad Rani ◽  
Muhamad Farhan Kamarun Saman ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Gas Separation ◽  
Polymer Concentration ◽  
Skin Layer ◽  
Conventional Technique ◽  
Poly Lactic Acid ◽  
Inversion Method ◽  
Separation Performance ◽  
Evaporation Time ◽  
Gas Separation Performance

Membrane technology in gas separation application was commercialized approximately 30 years ago because of a number of advantages offered compare to the conventional technique. The use of poly (lactic acid) (PLA), a biodegradable polymer, as a membrane material would assist the reduction of depending to petroleum-based polymer. This study investigated the effect of evaporation time to the gas separation performance of PLA membrane. Membrane prepared from polymer solution consist of PLA and dicholoremethane (DCM) as solvent was fabricated using pneumatically controlled casting system with dry/wet phase inversion method. Permeation test was conducted using pure carbon dioxide and methane gas. The results revealed that as the evaporation time increased, the pore size and surface porosity decreased, while the skin layer thickness increased. Although the morphology of the prepared membranes showed the desirable structure, the gas separation performance of the membrane prepared with polymer concentration of 15wt% and 60s evaporation time was found to be promising but not yet commercially ready.

scholarly journals Investigation on compatibility of PLA/PBAT blends modified by epoxy-terminated branched polymers through chemical micro-crosslinking

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Bo Wang ◽  
Yujuan Jin ◽  
Kai’er Kang ◽  
Nan Yang ◽  
Yunxuan Weng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Sem Analysis ◽  
Branched Polymers ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Butylene Terephthalate ◽  
The Difference ◽  
Physical And Chemical ◽  
The Impact

AbstractIn this study, a type of epoxy-terminated branched polymer (ETBP) was used as an interface compati- bilizer to modify the poly lactic acid (PLA)/poly(butylene adipate-co-butylene terephthalate) (PBAT) (70/30) blends. Upon addition of ETBP, the difference in glass transition temperature between PLA and PBAT became smaller. By adding 3.0 phr of ETBP, the elongation at break of the PLA/PBAT blends was found increased from 45.8% to 272.0%; the impact strength increased from 26.2 kJ·m−2 to 45.3 kJ·m−2. In SEM analysis, it was observed that the size of the dispersed PBAT particle decreased with the increasing of ETBP content. These results indicated that the compatibility between PLA and PBAT can be effectively enhanced by using ETBP as the modifier. The modification mechanism was discussed in detail. It proposes that both physical and chemical micro-crosslinking were formed, the latter of which was confirmed by gel content analysis.

Effect of Size on Degradation of Porous Poly(Lactic Acid) Scaffold

2011 ◽  
Vol 311-313 ◽  
pp. 1741-1745
Author(s):  
Chao Guo ◽  
Xiao Bo Sheng ◽  
Cheng Lin Chu ◽  
Yin Sheng Dong
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Mass Loss ◽  
Porous Scaffold ◽  
Repeat Unit ◽  
Poly Lactic Acid ◽  
Porous Scaffolds ◽  
Degradation Behaviors ◽  
The Difference ◽  
Autocatalytic Effect

Poly (lactic acid) (PLA) scaffolds with different sizes are often fabricated for various requirements. A cellular automaton simulation was used to investigate the effect of the size on the degradation behaviors of porous PLA scaffolds. Four porous PLA scaffolds with 90% initial porosity and different sizes were established by a novel repeat unit method. Mass loss and the change in molecular weight during the degradation were simulated. The results indicate that mass loss is related to the size of the porous scaffold while molecular weight change is independent on the size. With the size of the porous scaffold increasing, the mass loss increases while the difference in mass loss between the scaffolds with different sizes decreases. All these changes can be attributed to the difference in the autocatalytic effect and corresponding oligomer diffusion ability of the porous scaffolds with different sizes.

Surface Modification of Poly(Lactic Acid) Microspheres via Gamma Irradiation

2017 ◽  
Vol 264 ◽  
pp. 128-131 ◽  
Author(s):  
Zahroh Hasanah Augustini Ninaya ◽  
Zuratul Ain Abdul Hamid
Keyword(s):  
Lactic Acid ◽  
Maleic Anhydride ◽  
Gamma Irradiation ◽  
Polymer Surface ◽  
Poly Lactic Acid ◽  
Γ Irradiation ◽  
Sem Images ◽  
Dose Irradiation ◽  
Before And After ◽  
The Difference

Irradiation technique is one of methods used in modification of polymer surface although it has been used in sterilization for decades. It allows establishing simple and compact technique, non-contaminated with residues of toxic initiators, crossing agents or other additives. This study is to evaluate the effects of different gamma (γ) irradiation doses on poly (lactic acid) (PLA) microsphere surface grafted with maleic anhydride (MAH). Source of γ-irradiation used is 60Co and dose irradiation used in this study is10, 30, 50, 70, 90 and 110 kGy. Characterization was performed on samples before and after irradiation by FTIR, SEM and DSC. Results of FTIR suggest maleic anhydride successfully grafted onto PLA microsphere. Data from DSC shows thermal property of PLA changed after irradiation where the crystallization is increased compared to neat PLA. SEM images showed the difference of the PLA microspheres before and after γ irradiation. Neat PLA microspheres had a smooth surface, while after irradiation, the surface become rough. Degradation of microspheres observed by SEM as in suggest that PLA microspheres is degrade by bulk degradation. Gamma irradiation not only modified the surface of PLA microspheres by successfully grafting the maleic anhydride and increase surface roughness, it also affected the bulk properties of PLA microspheres.

Compatibility of Polyvinylidene Difluorid/Polyurethane and Preparation of Composite Tubular Membrane

2014 ◽  
Vol 936 ◽  
pp. 212-217
Author(s):  
Dan Ying Zuo ◽  
Hong Jun Li ◽  
Chang Hai Yi ◽  
Hou Lei Gan
Keyword(s):  
Phase Inversion ◽  
Water Flux ◽  
Mixing Enthalpy ◽  
Inversion Method ◽  
Membrane Porosity ◽  
Phase Inversion Method ◽  
Tubular Membranes ◽  
Parameter Theory ◽  
Precipitation Phase ◽  
Liquid Liquid Phase Separation

The compatibility of polyvinylidene difluorid (PVDF) and polyurethane (PU), the thermodynamics of the PVDF/PU/DMF (N-N-Dimethylformamide) membrane-forming systems were studied, and the composite tubular membranes of PVDF/PU-PET knitted fabric tube were prepared by the immersion precipitation phase inversion method. The results showed that the PVDF/PU system was partly compatible by the measurements of the solubility parameter theory, the mixing enthalpy, the viscosity. With PU content increasing, the gelation values increased and the instantaneous liquid-liquid phase separation was preferred to occur. The water flux of the composite tubular membranes were enhanced from 1264.81 to 2165.35 L/m2.h with PU content increasing from 10wt% to 40wt%, which resulted from the an increment of the membrane porosity and the improvement of the hydrophilicity.

Preparation and Morphology of SMPU/PNIPAM Semi-IPN Microporous Membrane

2011 ◽  
Vol 399-401 ◽  
pp. 1547-1551 ◽  
Author(s):  
Shu Mei Zhao ◽  
Zheng Wei Dai ◽  
Hai Ning Lv ◽  
Yuan Xue
Keyword(s):  
Pore Structure ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Coagulation Bath ◽  
Inversion Method ◽  
Large Pore ◽  
Ft Ir ◽  
Phase Inversion Method ◽  
Shape Memory Polyurethane ◽  
Precipitation Phase

Microporous membranes were prepared by immersion precipitation phase inversion method from the semi-interpenetrating polymer network (semi-IPN) of shape memory polyurethane (SMPU) and poly (N-isopropylacrylamide) (PNIPAM). The influence of material compostion and preparation procedure on the morphology of membranes such as pore structure and porosity was investigated by methods including Fourier-transform infrared (FT-IR) spectroscopy and scanning electronic microscopy (SEM). Both sponge-like structure and large-pore structure were found in the membranes. The introduction of PNIPAM content in the semi-IPN promotes the formation of large-pore structures and increases the porosity of membranes, due to the improvement of water diffusion into the casting solution. We also found that by increasing the temperature of coagulation bath and the concentration of DMF in the coagulation solution, the formation of large pores could be impeded, and membranes with more sponge-like structure could be prepared.

scholarly journals Innovative Bio-based Poly(Lactic Acid)/Poly(Alkylene Furanoate)s Fiber Blends for Sustainable Textile Applications

2021 ◽  
Author(s):  
Davide Perin ◽  
Daniele Rigotti ◽  
Giulia Fredi ◽  
George Z. Papageorgiou ◽  
Dimitrios N. Bikiaris ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Cross Section ◽  
Wet Spinning ◽  
Poly Lactic Acid ◽  
Future Research ◽  
Drawing Process ◽  
Microstructural Investigation ◽  
First Time ◽  
Thermal Stability Of

AbstractThis work aims at producing and investigating, for the first time, the microstructural and thermo-mechanical properties of fibers constituted by poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAFs) blends for textile applications. Two different PAFs have been investigated, i.e., poly(octylene furanoate) (P8F) and poly(dodecylene furanoate) (P12F), which have been blended with PLA in different concentrations and spun through a lab-made wet spinning device. The microstructural investigation of the fiber cross-section evidenced domains of PAFs homogeneously dispersed within the PLA matrix. The immiscibility of the produced blends was also suggested by the fact that the glass transition temperature of PLA was unaffected by the presence of PAF. The thermal stability of PLA was not substantially influenced by the PAF content, whereas the water absorption tendency decreased with an increase in P12F fraction. The mechanical properties of PLA/P8F blends decreased with the P8F amount, while for PLA/P12F fiber blends the stiffness and the strength were approximatively constant by increasing the P12F content. The drawing process, performed at 70 °C and with two different draw ratios, brought an interesting increase in the mechanical properties of PLA fibers upon P12F introduction. These promising results constitute the basis for future research on these innovative bio-based fibers.

scholarly journals New Understanding of the Difference in Filtration Performance between Anatase and Rutile TiO2 Nanoparticles through Blending into Ultrafiltration PSF Membranes

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 841
Author(s):  
Iulian-Gabriel Birsan ◽  
Stefan Catalin Pintilie ◽  
Laurentia Geanina Pintilie ◽  
Andreea Liliana Lazar ◽  
Adrian Circiumaru ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Crystalline Structure ◽  
Performance Index ◽  
Phase Inversion ◽  
Membrane Properties ◽  
Inversion Method ◽  
Overall Performance ◽  
The Difference ◽  
Phase Inversion Method ◽  
Tio2 Rutile

The blending of nanomaterials into a polymeric matrix is a method known for its ability, under certain circumstances, to lead to an improvement in membrane properties. TiO2 nanoparticles have been used in membrane research for the last 20 years and have continuously shown promise in this field of research. Polysulfone (PSf) membranes were obtained through the phase inversion method, with different TiO2 nanoparticle concentrations (0, 0.1, 0.5, and 1 wt.%) and two types of TiO2 crystalline structure (anatase and rutile), via the addition of commercially available nanopowders. Research showed improvement in all studied properties. In particular, the 0.5 wt.% TiO2 rutile membrane recorded an increase in permeability of 139.7% compared to the control membrane. In terms of overall performance, the best nanocomposite membrane demonstrated a performance index increase of 71.1% compared with the control membrane.

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