scholarly journals Preparation of Crystallites for Oriented Poly(Lactic Acid) Films Using a Casting Method under a Magnetic Field

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1083 ◽  
Author(s):  
Shuta Hara ◽  
Shuto Watanabe ◽  
Kohki Takahashi ◽  
Shigeru Shimizu ◽  
Hiroki Ikake

Poly-l-lactic acid (PLLA) has biocompatibility and unique characteristics such as piezoelectric properties. This attracts attention not only in the environmental field but also in the biomedical and electronic materials fields. In recent years, the literature about orienting PLLA crystals has been promoting new applications for PLLA such as high strength fiberization and piezoelectric properties. This paper presents a new technique to orient the PLLA crystalline through casting under magnetic irradiation. The advantage of this technique is that it is possible to radiate the magnetic field to the PLLA crystalline in an extremely low viscosity environment. Moreover, the heat treatment condition was optimized in order to improve the low crystallinity of casting, and it succeeded in producing a PLLA film with a high degree of orientation and high crystallinity. Furthermore, PLLA/1-butyl-3-methylimidazolium dibutylphosphate (bmimjdbp) composite films were prepared under the same conditions, and this also succeeded in the further improvement of crystallinity.

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2621 ◽  
Author(s):  
Hai Chi ◽  
Wenhui Li ◽  
Chunli Fan ◽  
Cheng Zhang ◽  
Lin Li ◽  
...  

The microstructure, thermal properties, mechanical properties and oxygen and water vapor barrier properties of a poly(lactic acid) (PLA)/nano-TiO2 composite film before and after high pressure treatment were studied. Structural analysis showed that the functional group structure of the high pressure treated composite film did not change. It was found that the high pressure treatment did not form new chemical bonds between the nanoparticles and the PLA. The micro-section of the composite film after high pressure treatment became very rough, and the structure was depressed. Through the analysis of thermal and mechanical properties, high pressure treatment can not only increase the strength and stiffness of the composite film, but also increase the crystallinity of the composite film. Through the analysis of barrier properties, it is found that the barrier properties of composite films after high pressure treatment were been improved by the applied high pressure treatment.


Materials ◽  
2017 ◽  
Vol 10 (6) ◽  
pp. 659 ◽  
Author(s):  
Zhuangzhuang Chu ◽  
Tianrui Zhao ◽  
Lin Li ◽  
Jian Fan ◽  
Yuyue Qin

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chaitra Venkatesh ◽  
Yuanyuan Chen ◽  
Zhi Cao ◽  
Shane Brennan ◽  
Ian Major ◽  
...  

Abstract Poly (lactic acid)/halloysite nanotube (PLA/HNT) nanocomposites have been studied extensively over the past few years owing to the interesting properties of the polymer, PLA, and the nanoclay, HNT, individually and as composites. In this paper, the influence of the screw speed during extrusion was investigated and was found to have a significant impact on the mechanical and thermal performance of the extruded PLA/HNT nanocomposites. To determine the effect of screw speed on PLA/HNT nanocomposites, 5 and 10 wt% of HNTs were blended into the PLA matrix through compounding at screw speeds of 40, 80, and 140 rpm. Virgin PLA was compounded for comparison. The resultant polymer melt was quench cooled onto a calendar system to produce composite films which were assessed for mechanical, thermal, chemical, and surface properties. Results illustrate that in comparison to 40 and 80 rpm, the virgin PLA when compounded at 140 rpm, indicated a significant increase in the mechanical properties. The PLA/HNT 5 wt% nanocomposite compounded at 140 rpm showed significant improvement in the dispersion of HNTs in the PLA matrix which in turn enhanced the mechanical and thermal properties. This can be attributed to the increased melt shear at higher screw speeds.


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.


2013 ◽  
Vol 53 (11) ◽  
pp. 2308-2317 ◽  
Author(s):  
E.D. Pereira ◽  
F.G. Souza ◽  
C.I. Santana ◽  
D.Q. Soares ◽  
A.S. Lemos ◽  
...  

2007 ◽  
Vol 106 (2) ◽  
pp. 801-810 ◽  
Author(s):  
L. S. Liu ◽  
V. L. Finkenstadt ◽  
C.-K. Liu ◽  
T. Jin ◽  
M. L. Fishman ◽  
...  

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.


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