scholarly journals Isolation, Preparation and Characterization of Polylactic Acid Film Reinforced with Nano silica

2021 ◽  
Vol 2063 (1) ◽  
pp. 012028
Author(s):  
Zainab A Ali ◽  
Alaa Karem Niamah ◽  
Hannosh Widad Salih

Abstract Lactic acid was isolated by using microbial fermentation in whey media which was carried out by local strain Lactobacillus paraplantarum then polymerized using the acidic medium’s polycondensation method. FTIR and H-NMR were used to characterize the isolated lactic acid monomer and polyalctic acid (PLA), and the results confirmed the chemical structures of the isolated lactic acid and PLA. GPC techniques were used to determine the molecular weight and molecular weight distribution of the prepared PLA; the result showed that the Polydispersity index (PDI) was 2.51. The Biodegradable composite films of poly lactic acid (PLA)/Nano silica powder were prepared by the composite film casting method using dichloromethane as solvent. In contrast, Nano silica was synthesis from hydrolysis of tetra ethoxysilane and was loaded in PLA in 1 to5 wt. %. The films were subjected to a tensile strength study. Thermogravimetric analysis (TGA) and differential thermal analysis (DSC) were used to evaluate PLA. Also, water absorption of the prepared composites was studied, and the result showed that the thermal stability and water absorption of these prepared films were increased with an increasing percentage of Nano silica, while the percentage of crystallinity of the PLA evaluated from DSC was 28 %.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  

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.


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.


2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.


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

2016 ◽  
Vol 852 ◽  
pp. 10-15
Author(s):  
Sahas Bansal ◽  
M. Ramachandran ◽  
Pramod Raichurkar

Green composites shaped by mixture of biodegradable polymers and natural fibers have spellbound massive interest in current years due to their environmentally valuable properties and also to decrease our dependency on the non-renewable resources. Due to the environmental advantages and light weight of natural fibers, an increasing quantity of natural fibers has been used to replace synthetic fibers composites. Coir fiber poly-lactic acid (PLA)/ poly-propylene (PP) resin reinforced polymeric composites have been developed with 90o orientation. The composition of PLA and PP for resin preparation is taken in the ratio 95:05 whereas for the composite, resins and coir fiber in 80:20. The compression molding technique is applied and then the tests are carried out. Mechanical tests (Impact and Hardness), Micro structural analysis (Fourier Transform Infrared Spectroscopy and Optical Imaging) and Differential Scanning Calorimetry are conducted. According to the investigational verification, the new biodegradable composite shows significant results on par with synthetic/ man made composites and the advantages of using bio-composites has been indicated with simplicity.


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.


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