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

Shuta Hara,Shuto Watanabe,Kohki Takahashi,Hiroki Ikake,Shigeru Shimizu

doi:10.3390/polym10101083

Abstract

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.

Highlights

In recent years, poly(L-lactic acid) (PLLA) has been well-known as a novel material which can be used to save petroleum resources and reduce carbon dioxide
We focused on the crystallization of Poly-L-lactic acid (PLLA) using the cast method under a magnetic field because of the low viscous environment this provided during crystallization, crystal growth, and the orientation process
The X-ray diffraction (XRD) pattern of neat PLLA cast film (PLLA0T) and oriented film (PLLA10T) is shown in Figure 2 shows the result of X-ray azimuthal scans along the (110)/(200) plane of PLLA0T and PLL10T

Summary

Introduction

Poly(L-lactic acid) (PLLA) has been well-known as a novel material which can be used to save petroleum resources and reduce carbon dioxide. PLLA has attracted increasing attention in ecological fields, in the biomedical field [1,2], and in electronic devices [3] because of its unique properties, such as its nontoxicity to the human body and the piezoelectric effect [2,4]. Much effort has been made to regulate the PLLA crystal due to how greatly this influences its macro-physical properties. Depending on the crystallization conditions, PLLA exhibits different crystalline forms, such as alpha-, beta-, and gamma-forms and their mixtures [5,6,7,8]. The alpha-crystal of PLLA is usually prepared under ordinary conditions, such as through melting or solutions. It is orthorhombic and has a 103 helical chain conformation [5]

Methods

Results

Conclusion