Thermomechanical Study and Thermal Behavior of Plasticized Poly(Lactic Acid) Nanocomposites

2021 ◽  
Vol 317 ◽  
pp. 333-340
Author(s):  
Mohammed Zorah ◽  
Izan Roshawaty Mustapa ◽  
Norlinda Daud ◽  
Nahida Jumah ◽  
Nur Ain Syafiqah Sudin ◽  
...  

Poly (lactic acid) (PLA) is a useful alternative to petrochemical commodity material used in such as in food packaging industries. Due to its inherent brittleness, low thermal stability, and poor crystallization, it needs to improve its properties, namely in terms of thermal and mechanical performance. The plasticized PLA composites reinforced with nanofiller were prepared by solvent casting and hot press methods. Thermal and mechanical properties, as well as the crystallinity study of these nanocomposites, were investigated to study the effect of tributyl citrate (TBC) and TiO2 on the PLA composites. The addition of TBC improved the flexibility and crystallinity of the composites. Reinforcement of TiO2 was found as a practical approach to improve the mechanical properties, thermal stability, and enhanced crystalline ability for plasticized PLA nanocomposites. Based on the results achieved in this study, the composite with 3.5% nanofiller (pPLATi3.5) presented the optimum set of mechanical properties and improved thermal stability.

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 844 ◽  
pp. 65-68
Author(s):  
Pranee Nuinu ◽  
Kittikorn Samosorn ◽  
Kittisak Srilatong ◽  
Siripa Tongbut ◽  
Sayant Saengsuwan

The aim of this research was to reduce and improve the brittleness and thermal properties of poly lactic acid (PLA), respectively. Epoxidized natural rubber (ENR) was used to enhance the toughness and rutile titanium dioxide (R-TiO2) as filler was also incorporated to improve the thermal properties of the PLA. 10wt% ENR with epoxidation contents of 25 mol% (ENR25) and 50 mol% (ENR50) and various R-TiO2contents (0-10 phr)were compounded with PLA by using a twin-screw extruder at 155-165°C and a rotor speed of 40 rpm. The pellets of blends were then formed a thin film using a cast film extruder machine and cooled down under air flow. Thermal and mechanical properties and morphology of PLA/ENR/R-TiO2thin film were investigated. The crystallinity of PLA was found to increase with addition of ENR. The mechanical properties of thin film showed that the ENR50 enhanced the elongation but reduced the tensile strength of PLA with addition of R-TiO2at 5 and 10 phr, respectively. The TGA indicated that the addition of 10 phr R-TiO2increased in the decomposition temperature at 5% weight loss (Td5%) of PLA/ENR film. Thus the thermal stability of PLA/ENR50 was found to improve with addition of R-TiO2. From morphology study, the ENR50 phase showed a good dispersion in the PLA matrix. In conclusion, the addition of ENR and R-TiO2was found to enhance both toughness and thermal stability of PLA.


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.


2015 ◽  
Vol 54 (43) ◽  
pp. 10945-10951 ◽  
Author(s):  
Hui Ma ◽  
Jiajia Shen ◽  
Qun Yang ◽  
Jie Zhou ◽  
Shuangshuang Xia ◽  
...  

2019 ◽  
Vol 33 (10) ◽  
pp. 1383-1395
Author(s):  
Hongjuan Zheng ◽  
Zhengqian Sun ◽  
Hongjuan Zhang

Poly(lactic acid) (PLA) has good environmental compatibility, however, its high brittleness, slow rate of crystallization, and low heat distortion temperature restrict its widespread use. To overcome these limitations, in this study, PLA was mixed with walnut shell (WS) powders. The effects of WS powders on the morphology and the thermal and mechanical properties of PLA were investigated. The products were characterized by differential scanning calorimetry (DSC), infrared (IR) spectroscopy, polarizing optical microscopy (POM), and various mechanical property testing techniques. The results showed that WS powders had a significant effect on the morphology and the thermal and mechanical properties of PLA. The tensile strength, impact strength, and elongation at break of the PLA/WS composites first increased and then decreased with the increasing addition of WS powders. When the addition of WS powders was about 0.5 wt%, they reached maximum values of 51.2 MPa, 23.3 MPa, and 19.0%, respectively. Compared with neat PLA, the spherulite grain size of the composites could be reduced and many irregular polygons were formed during crystallization. The melting, cold crystallization, and glass-transition temperatures of the composites were lower than those of neat PLA.


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