A facile strategy for preparation of strong tough poly(lactic acid) foam with a unique microfibrillated bimodal micro/nano cellular structure

2022 ◽  
Author(s):  
Pei Xiang ◽  
Liangcheng Gou ◽  
Yuan Zou ◽  
Binyi Chen ◽  
Siwen Bi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Cellular Structure ◽  
Poly Lactic Acid

scholarly journals Tuning cell structure and expansion ratio of thick-walled biodegradable poly(lactic acid) foams prepared using supercritical CO2

2019 ◽  
Vol 56 (1) ◽  
pp. 89-104 ◽  
Author(s):  
Lin-Qiong Xu ◽  
Han-Xiong Huang
Keyword(s):  
Lactic Acid ◽  
Constant Temperature ◽  
Cellular Structure ◽  
Cell Structure ◽  
Expansion Ratio ◽  
Poly Lactic Acid ◽  
Time Range ◽  
Formation Mechanisms ◽  
Saturation Time ◽  
Temperature Mode

Thick-walled poly(lactic acid) samples are foamed using supercritical carbon dioxide as physical foaming agent over a wide saturation time range using a constant-temperature mode and a wide foaming pressure range using the constant-temperature mode and a varying-temperature mode. Using the constant-temperature mode, three regions with no-celled core and two regions with cells of different diameters appear on the fractured surfaces of the foamed samples prepared at 5 and 10 min saturation times, respectively, whereas a relatively uniform cellular structure is obtained at 20–180 min saturation times. Raising the foaming pressure can improve the cellular structure uniformity. Moreover, prolonging saturation time or raising foaming pressure results in rupture of more cell walls and so formation of open-celled structure to a certain extent. Using the varying-temperature mode, a bimodal cellular structure with stamen-like cells and a trimodal cellular structure with an extraordinarily high expansion ratio (76.2) are successively achieved during raising the foaming pressure (18–22 MPa). The formation mechanisms for the bimodal and trimodal cellular structures are analyzed based on the result of the foaming pressure effect on the cellular structure in the foamed poly(lactic acid) samples prepared using the constant-temperature mode.

Effects of Poly(butyleneadipate-co-terephthalate) as a Macromolecular Nucleating Agent on the Crystallization and Foaming Behavior of Biodegradable Poly(lactic acid)

2017 ◽  
Vol 36 (2) ◽  
pp. 75-96 ◽  
Author(s):  
Wei Liu ◽  
Peng Chen ◽  
Xiangdong Wang ◽  
Fuchun Wang ◽  
Yujiao Wu
Keyword(s):  
Lactic Acid ◽  
Cellular Structure ◽  
Crystal Morphology ◽  
Nucleating Agent ◽  
Expansion Ratio ◽  
Poly Lactic Acid ◽  
Surrounding Area ◽  
Foaming Behavior ◽  
Biodegradable Poly ◽  
Macromolecular Crystallization

The effect of a bio-based macromolecule, poly(butylene adipate-co-terephthalate) (PBAT), on the crystallization and foaming behavior of poly(lactic acid) (PLA) was evaluated. The crystallization kinetics results show that the addition of PBAT improved the crystallization of PLA by increasing the overall crystallinity and enhancing the crystal morphology of PLA. The massive crystallization zones may have prevented the escape of foaming gases to the surrounding area; the expansion ratio of the PLA foams increased from 4.87 to 10.94. Thus, a novel macromolecular crystallization nucleating agent for PLA was developed; the effect of the crystallization of PLA on its foaming behavior was also investigated. A high expansion ratio and finer cellular structure of PLA foam were obtained by optimizing the PBAT content.

Preparation and properties of flexible poly(lactic acid) blend foams

2018 ◽  
Vol 37 (4-6) ◽  
pp. 189-205 ◽  
Author(s):  
Liu Wei ◽  
He Shicheng ◽  
Zhou Hongfu
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Constitutive Model ◽  
Rheological Behavior ◽  
Cellular Structure ◽  
High Performance ◽  
Poly Lactic Acid ◽  
Compression Property ◽  
Rigid Particles ◽  
Foaming Behavior

High-performance poly(lactic acid) (PLA) foam has been recognized as a promising material because of its biodegradability. However, low flexibility and foamability of PLAs has limited its use in different fields. In this study, a blend-toughening technology was used to toughen PLA and prepare flexible foams. The mechanical properties of PLA blends were evaluated, and the cellular structure of these foaming blends was characterized. The results show that the blending components significantly affected the overall mechanical properties and foaming behavior of PLA. The toughness of PLA was enhanced by adding poly(butylene adipate- co-terephthalate) (PBAT) and rigid particles. The rheological behavior of PLA was also affected by adding PBAT. Therefore, the cellular structure of the PLA foams was affected. A constitutive model was also used to fit the experimental results of the compression property of the PLA foam.

Fabrication of poly (lactic acid) foams using supercritical nitrogen

2020 ◽  
Vol 39 (4) ◽  
pp. 172-182 ◽  
Author(s):  
Fatemeh Farhanmoghaddam ◽  
Azizeh Javadi
Keyword(s):  
Lactic Acid ◽  
Electrical Resistance ◽  
Cellular Structure ◽  
High Cell Density ◽  
Cell Structure ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
High Cell ◽  
Blowing Agent ◽  
Foaming Process

In this article, poly (lactic acid) (PLA) was foamed via batch foaming using supercritical nitrogen as a physical blowing agent by two methods, conventional foaming process (CFP) and low-temperature foaming process (LTFP). The fabrication processes, cell morphologies, thermal properties, crystallization behavior, and electrical resistance of resulted foams were studied to investigate the effect of foaming on these properties of PLA. It was found that the foams resulted from CFP method have micrometric cell sizes, while LTFP method led to nanometric cell structure and high cell density. Also scanning electron microscopy showed that the PLA foams have a heterogeneous cellular structure. The results showed that the foaming process increased the melting point and degree of crystallinity of PLA, which led to decrease in the electrical resistance of samples.

Electrical Properties of Heat-Treated Poly-Lactic Acid

2011 ◽  
Vol 131 (5) ◽  
pp. 395-400 ◽  
Author(s):  
Toru Oi ◽  
Katsuyoshi Shinyama ◽  
Shigetaka Fujita
Keyword(s):  
Lactic Acid ◽  
Electrical Properties ◽  
Poly Lactic Acid ◽  
Heat Treated

Dielectric Breakdown Properties of Poly-Lactic Acid with Spherulites Growth

2014 ◽  
Vol 134 (4) ◽  
pp. 237-242
Author(s):  
Naru Matsugasaki ◽  
Katsuyoshi Shinyama ◽  
Shigetaka Fujita
Keyword(s):  
Lactic Acid ◽  
Dielectric Breakdown ◽  
Poly Lactic Acid
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