Measurement and Simulation of Thermal Stability of Poly(Lactic Acid) by Thermogravimetric Analysis

2009 ◽  
Vol 37 (4) ◽  
pp. 102271 ◽  
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Mu-Hoe Yang ◽  
Yeuh-Hui Lin
2011 ◽  
Vol 335-336 ◽  
pp. 153-156
Author(s):  
Xue Li Wu ◽  
Jian Hui Qiu ◽  
Lin Lei ◽  
Yang Zhao ◽  
Eiichi Sakai

To consider the effective utilization of plastics and agricultural wastes, rice straw fibre was extracted from agricultural wastes, and then composited with polylactic acid(PLA). The thermal stability of straw/poly(lactic acid)(straw/PLA) composites decreased (Thermogravimetric Analysis, TGA). Tensile strength, fracture strain and sharply impact strength of straw/PLA were decreased with the increase of filler content and grain size of straw. Yong’s modulus were increased as the increasing of straw content.


2019 ◽  
Vol 972 ◽  
pp. 172-177
Author(s):  
Sirirat Wacharawichanant ◽  
Patteera Opasakornwong ◽  
Ratchadakorn Poohoi ◽  
Manop Phankokkruad

This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.


2020 ◽  
Vol 837 ◽  
pp. 174-180
Author(s):  
Sirirat Wacharawichanant ◽  
Attachai Sriwattana ◽  
Kulaya Yaisoon ◽  
Manop Phankokkruad

This work studied the morphology, mechanical and thermal properties of poly (lactic acid) (PLA)/ethylene-octene copolymer (EOC) (80/20) blends with different organoclay types. Herein, EOC was introduced to toughening PLA by melt blending and organoclay was used to improve compatibility and tensile properties of the blends. The two organoclay types were nanoclay surface modified with aminopropyltriethoxysilane 0.5-5 wt% and octadecylamine 15-35% (Clay-ASO) and nanoclay surface modified with dimethyl dialkyl (C14-C18) amine 35-45 wt% (Clay-DDA). The organoclay contents were 3, 5 and 7 phr. Scanning electron microscope (SEM) observation results revealed PLA/EOC blends demonstrated a two-phase separation of dispersed EOC phase and PLA matrix phase. The addition of organoclay significantly improved the compatibility between PLA and EOC phases due to EOC droplet size decreased dominantly in PLA matrix, so organoclay could act as an effective compatibilizer. The incorporation of organoclay increased significantly tensile strength of PLA/EOC/organoclay composites while Young’s modulus increased with 5 phr of organoclay. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-ASO in the blends could improve the thermal stability of the PLA/EOC blends.


2012 ◽  
Vol 24 (8) ◽  
pp. 738-746 ◽  
Author(s):  
Rui Zhang ◽  
Xifu Xiao ◽  
Qilong Tai ◽  
Hua Huang ◽  
Jian Yang ◽  
...  

Lignin–silica hybrids (LSHs) were prepared by sol–gel method and characterized by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). LSH and ammonium polyphosphate (APP) were added into poly(lactic acid) (PLA) as a novel intumescent flame-retardant (IFR) system to improve the flame retardancy of PLA. The flame-retardant effect of APP and LSH in PLA was studied using limiting oxygen index (LOI), vertical burning (UL-94) tests and cone calorimeter. The thermal stability of PLA/APP/LSH composites was evaluated by thermogravimetric analysis (TGA). Additionally, the morphology and components of char residues of the IFR-PLA composites were investigated by SEM and XPS. With the addition of APP/LSH to PLA system, the morphology of the char residue has obviously changed. Compared with PLA/APP and PLA/APP/lignin, a continuous and dense intumescent charring layer with more phosphor in PLA composites is formed, which exhibits better flame retardancy. All the results show that the combination of APP and LSH can improve the flame-retardant property and increase the thermal stability of PLA composites greatly.


1999 ◽  
Vol 48 (10) ◽  
pp. 980-984 ◽  
Author(s):  
A Babanalbandi ◽  
D J T Hill ◽  
D S Hunter ◽  
L Kettle

2018 ◽  
Vol 37 (12) ◽  
pp. 841-852 ◽  
Author(s):  
Guang Hu ◽  
Shenyang Cai ◽  
Yinghui Zhou ◽  
Naiwen Zhang ◽  
Jie Ren

Three different kinds of surface treatment procedures were used to modify the surface of bamboo fiber: alkali solution treatment (NaOH), alkali and silane coupling agent treatment (NaOH–KH550) and alkali and titanate coupling agent treatment (NaOH–NDZ201). Then the bamboo fiber reinforced poly (lactic acid) composites were prepared by Haake Mixer and characterized by FTIR spectroscopy, mechanics performance tests, differential scanning calorimetry analysis, thermogravimetric analysis, Vicat softening temperature, X-ray diffraction analysis and scanning electron microscopy. The results showed that incorporation of surface-treated bamboo fiber obviously improved the mechanical properties of poly (lactic acid). Especially, the tensile, flexural and impact strengths of poly (lactic acid) containing NaOH–NDZ201-treated bamboo fiber were higher than those of poly (lactic acid) containing NaOH and NaOH–KH550-treated bamboo fiber. Moreover, the NaOH–NDZ201-treated bamboo fiber also greatly enhanced the thermal stability of poly (lactic acid). The improvement of mechanical strengths and thermal stability of poly (lactic acid)/bamboo fiber composites might be due to the better interfacial adhesion between poly (lactic acid) and NaOH–NDZ201-treated bamboo fiber.


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