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.

scholarly journals Poly(lactic Acid): A Versatile Biobased Polymer for the Future with Multifunctional Properties—From Monomer Synthesis, Polymerization Techniques and Molecular Weight Increase to PLA Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Practical Applications ◽  
Decomposition Reactions ◽  
Melt Polycondensation ◽  
Polymerization Conditions ◽  
Molecular Weight Increase

Environmental problems, such as global warming and plastic pollution have forced researchers to investigate alternatives for conventional plastics. Poly(lactic acid) (PLA), one of the well-known eco-friendly biodegradables and biobased polyesters, has been studied extensively and is considered to be a promising substitute to petroleum-based polymers. This review gives an inclusive overview of the current research of lactic acid and lactide dimer techniques along with the production of PLA from its monomers. Melt polycondensation as well as ring opening polymerization techniques are discussed, and the effect of various catalysts and polymerization conditions is thoroughly presented. Reaction mechanisms are also reviewed. However, due to the competitive decomposition reactions, in the most cases low or medium molecular weight (MW) of PLA, not exceeding 20,000–50,000 g/mol, are prepared. For this reason, additional procedures such as solid state polycondensation (SSP) and chain extension (CE) reaching MW ranging from 80,000 up to 250,000 g/mol are extensively investigated here. Lastly, numerous practical applications of PLA in various fields of industry, technical challenges and limitations of PLA use as well as its future perspectives are also reported in this review.

scholarly journals An investigation on the degradation behaviors of Mg wires/PLA composite for bone fixation implants: influence of wire content and load mode

2021 ◽  
Vol 28 (1) ◽  
pp. 39-47
Author(s):  
Xuan Li ◽  
Yu Cong ◽  
Jisheng Sui ◽  
Xiaolong Li
Keyword(s):  
Lactic Acid ◽  
Dynamic Load ◽  
Degradation Rate ◽  
Convective Transport ◽  
Poly Lactic Acid ◽  
Mechanical Loss ◽  
Bone Fixation ◽  
Load Mode ◽  
Degradation Behaviors ◽  
Ph Decrease

Abstract Poly-lactic acid based biocomposite strengthened with magnesium alloy wires (Mg wires/PLA composite) is prepared for bone fixation implantation. The influence of wire content and load mode on the degradation performances of the composite and its components is studied. The result suggests the degradation of Mg wires could slow down the pH decrease originated from the degradation of PLA, while a relatively high wire content contributes to descend the degradation rate of Mg wire in the composite. Dynamic load significantly promotes the mechanical loss of the specimens. After 30 days immersion, the Sb retention is about 65%, 52% and 55%, respectively for pure PLA, the composite at 10 vol% and 20 vol% under dynamic load, comparing to 75%, 70% and 72% under no load. Moreover, dynamic load could further mitigate the degradation of Mg wires by increasing convective transport of acidic products out of the composite.

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.

scholarly journals Blends of low molecular weight of poly lactic acid (PLA) with gondorukem (gum rosin)

2018 ◽  
Author(s):  
Mujtahid Kaavessina ◽  
Sperisa Distantina ◽  
Achmad Chafidz ◽  
Aditya Utama ◽  
Venisa Mega Puteri Anggraeni
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Low Molecular Weight ◽  
Gum Rosin

Study of the Properties of Plasticised Poly(Lactic Acid) with Poly(1,3-Butylene Adipate)

2008 ◽  
Vol 16 (9) ◽  
pp. 597-604 ◽  
Author(s):  
Wang Ning ◽  
Zhang Xingxiang ◽  
Yu Jiugao ◽  
Fang Jianming
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Glass Transition ◽  
Renewable Resources ◽  
Migration Rate ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Migration Resistance ◽  
Area Of Application

Poly(lactic acid) (PLA) is a biodegradable thermoplastic that can be produced from renewable resources, and so was considered as a major alternative to petroleum-based plastics for packaging applications. However, plasticisation of PLA was required in order to obtain films with sufficient flexibility. Poly(1, 3-butylene adipate) (PBA) was used as a novel plasticiser for PLA, and acetyltributyl citrate (ATBC) was used as the control. FTIR revealed that interaction took place between PLA and plasticiser. With an increasing plasticiser content, storage modulus and glass transition temperature decreased, but elongation at break increased. The elongation at break of PBA-plasticised PLA (PBA content 30 wt.%) could be above 600%, higher than that of ATBC-plasticised PLA (ATBC content 30 wt.%). Moreover, PBA was able to restrain thermally induced migration of plasticiser in plasticised PLA. It was also found that the migration rate of ATBC was directly proportional to the ATBC content in the blends. The rheology showed that the plasticiser could obviously decrease the shear viscosity and improve the fluidity of the blends. PBA was therefore recognised as a novel plasticiser for enhancing the properties of PLA. In particular, as a biodegradable polymer, PBA, when used as a plasticiser in PLA, can enhance migration resistance for its proper molecular weight. Moreover, the area of application of plasticised PLA is broadened.

scholarly journals Fused Deposition Modeling of Poly (lactic acid)/Macadamia Composites—Thermal, Mechanical Properties and Scaffolds

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 258 ◽  
Author(s):  
Xiaohui Song ◽  
Wei He ◽  
Huadong Qin ◽  
Shoufeng Yang ◽  
Shifeng Wen
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Fused Deposition Modeling ◽  
Poly Lactic Acid ◽  
Porous Scaffolds ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Structural Parts

In this work Macadamia nutshell (MS) was used as filler in fused deposition modeling (FDM) of Poly (lactic acid) (PLA) composites filaments. Composites containing MS both treated and untreated with alkali and silane were investigated by means of Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), Thermogravimetry (TG), scanning electron microscopy (SEM). The results showed that the treated MS composites had better thermal stability. Furthermore, compression tests were carried out. The PLA with 10 wt% treated MS composite was found possessing the best mechanical properties which was almost equivalent to that of the pure PLA. Finally, porous scaffolds of PLA/10 wt% treated MS were fabricated. The scaffolds exhibited various porosities in range of 30–65%, interconnected holes in size of 0.3–0.5 mm, micro pores with dimension of 0.1–1 μm and 37.92–244.46 MPa of elastic modulus. Those values indicated that the FDM of PLA/MS composites have the potential to be used as weight lighter and structural parts.

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