Interface compatibility and mechanisms of improved mechanical performance of starch/poly(lactic acid) blend reinforced by bamboo shoot shell fibers

2019 ◽  
Vol 136 (35) ◽  
pp. 47899 ◽  
Author(s):  
Mingjie Guan ◽  
Zhiwei Zhang ◽  
Cheng Yong ◽  
Keke Du
2019 ◽  
Vol 821 ◽  
pp. 89-95
Author(s):  
Wanasorn Somphol ◽  
Thipjak Na Lampang ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
...  

Poly (lactic acid) or PLA was reinforced by nanocellulose and polyethylene glycol (PEG), which were introduced into PLA matrix from 0 to 3 wt.% to enhance compatibility and strength of the PLA. The nanocellulose was prepared by TEMPO-mediated oxidation from microcrystalline cellulose (MCC) powder and characterized by TEM, AFM, and XRD to reveal rod-like shaped nanocellulose with nanosized dimensions, high aspect ratio and high crystallinity. Films of nanocellulose/PEG/PLA nanocomposites were prepared by solvent casting method to evaluate the mechanical performance. It was found that the addition of PEG in nanocellulose-containing PLA films resulted in an increase in tensile modulus with only 1 wt% of PEG, where higher PEG concentrations negatively impacted the tensile strength. Furthermore, the tensile strength and modulus of nanocellulose/PEG/PLA nanocomposites were higher than the PLA/PEG composites due to the existence of nanocellulose chains. Visual traces of crazing were detailed to describe the deformation mechanism.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4910 ◽  
Author(s):  
Alejandro Aragón-Gutierrez ◽  
Marina P. Arrieta ◽  
Mar López-González ◽  
Marta Fernández-García ◽  
Daniel López

Bionanocomposites based on poly (lactic acid) (PLA) and silica aerogel (SiA) were developed by means of melt extrusion process. PLA-SiA composite films were plasticized with 15 wt.% of acetyl (tributyl citrate) (ATBC) to facilitate the PLA processability as well as to attain flexible polymeric formulations for films for food packaging purposes. Meanwhile, SiA was added in four different proportions (0.5, 1, 3 and 5 wt.%) to evaluate the ability of SiA to improve the thermal, mechanical, and barrier performance of the bionanocomposites. The mechanical performance, thermal stability as well as the barrier properties against different gases (carbon dioxide, nitrogen, and oxygen) of the bionanocomposites were evaluated. It was observed that the addition of 3 wt.% of SiA to the plasticized PLA-ATBC matrix showed simultaneously an improvement on the thermal stability as well as the mechanical and barrier performance of films. Finally, PLA-SiA film formulations were disintegrated in compost at the lab-scale level. The combination of ATBC and SiA sped up the disintegration of PLA matrix. Thus, the bionanocomposites produced here show great potential as sustainable polymeric formulations with interest in the food packaging sector.


2017 ◽  
Vol 900 ◽  
pp. 7-11
Author(s):  
Muhammad Shoaib Butt ◽  
Jing Bai ◽  
Feng Xue

High-strength magnesium alloy (AZ31) reinforced poly-lactic acid (PLA) composite rods for potential application of bone fracture fixation prepared by plastic injection process on Mg rod.Thecomposities possess improved the interfacial bonding between poly-lactic acid and Mg rod due to the micro-anchoring which lead to better mechanical performance in Simulated body fluid solution.The present results indicated that this new PLA-clad Mg composite rods show good potential for biomedical applications.


2019 ◽  
pp. 089270571986461
Author(s):  
Kubra Coskun ◽  
Aysenur Mutlu ◽  
Mehmet Dogan ◽  
Ebru Bozacı

The effects of enzymatic treatments on the properties of coir fiber-reinforced poly(lactic acid) (PLA) were not found in the literature. Accordingly, the effects of various enzymatic treatments on the mechanical performance of the coir fiber-reinforced PLA composites were investigated in the current study. Four different enzymes, namely lipase, lactase, pectinase, and cellulase, were used. The mechanical properties of the composites were determined by the tensile, flexural, impact tests, and dynamic mechanical analysis. According to the test results, the use of enzyme treated coir fibers affected the mechanical properties except for the flexural properties with different extents depending upon their type. The tensile strength increased with the treatments of lipase and lactase, while the treatments with pectinase and cellulase had no remarkable effect. The impact strength was improved with enzymatic treatments except for pectinase. All enzymatic treatments improved the elastic modulus below the glass transition temperature. In brief, enzymatic treatments improved the interfacial adhesion between coir fiber and PLA via the waxes and fatty acids removal and/or the increment in surface roughness.


2017 ◽  
Vol 52 (6) ◽  
pp. 835-850 ◽  
Author(s):  
Hossein Mohammad Khanlou ◽  
Wayne Hall ◽  
Peter Woodfield ◽  
John Summerscales ◽  
Gaston Francucci

Bio-composites are increasingly being perceived as a green alternative to synthetic composites in many applications. However, the overall long-term durability of bio-composites is a major concern, particularly their ability for sustained performance under harsh and changing environmental conditions. This paper reports a detailed study on the effect of environmental conditions on the performance of flax/poly(lactic acid) bio-composites. Neat poly(lactic acid) and bio-composite samples were exposed to environments similar to those found outdoors: wet, freezing and humid. Moisture absorption and physical changes of specimens were periodically examined. Flexural and tensile properties were evaluated periodically to determine the detrimental effect of each exposure condition on the mechanical performance of bio-composites. Direct contact with liquid water is the most deteriorating environment for bio-composites. A drying process can partially restore the mechanical performance of these materials. Bio-composites can survive reliably in warm humid environments and in those that could create freeze and thaw cycles for short-term outdoor applications. The mechanisms and reasons involved in the degradation of the properties of green composites are discussed.


2016 ◽  
Vol 50 (30) ◽  
pp. 4189-4198 ◽  
Author(s):  
JM Ferri ◽  
I Gisbert ◽  
D García-Sanoguera ◽  
MJ Reig ◽  
R Balart

Orthophosphates are bioactive crystals with similar structure, in terms of elemental composition and crystal nature, to human bone. In this work, biocomposite materials were prepared with poly(lactic acid) (PLA) as matrix, and beta-tricalcium phosphate (β-TCP) as osteoconductive filler by extrusion-compounding followed by conventional injection molding. The β-TCP load content was varied in the 10–40 wt% range and the influence of the β-TCP load on mechanical performance of PLA/β-TCP composites was evaluated. Mechanical properties of composites were obtained by standardized tensile, flexural, impact, and hardness tests. Thermal analysis of composites was carried out by means of differential scanning calorimetry; degradation at high temperatures was studied by thermogravimetric analysis; and the effect of the β-TCP load on dynamical response of composites was studied by mechanical thermal analysis in torsion mode. The best-balanced properties were obtained for PLA composites containing 30 wt% β-TCP with a remarkable increase in the Young’s modulus. These materials offer interesting properties to be used as base materials for medical applications such as interference screws due to high stiffness and mechanical resistance.


Polymers ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 213 ◽  
Author(s):  
Hua-Mo Yin ◽  
Jing Qian ◽  
Jin Zhang ◽  
Zai-Fu Lin ◽  
Jian-Shu Li ◽  
...  

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