Effect of a Multifunctional Chain Extender on the Mechanical Properties and Thermal Stability of Poly (lactic acid) Synthesized via Direct Polycondensation

Nowadays, PLA is increasingly used as a packaging material, therefore it may appear in the petrol-based polymer waste stream. However, with the today’s mechanical recycling technologies PLA and PET bottles cannot be easily or cheaply separated. Therefore, our goal was to investigate the mechanical, morphological and thermal properties of different PET and PLA compounds in a wide range of compositions. We made different compounds from poly(ethylene-terephthalate) (PET) and poly(lactic acid) (PLA) by extrusion, and injection molded specimens from the compounds. We investigated the mechanical properties and the phase morphology of the samples and the thermal stability of the regranulates. PET and PLA are thermodynamically immiscible, therefore we observed a typical island-sea type morphology in SEM micrographs. When PLA was added, the mechanical properties (tensile strength, modulus, elongation at break and impact strength) changed significantly. The Young’s modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. The TGA results indicated that the incorporation of PLA decreased the thermal stability of the PET/PLA blends.

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Morphologies, mechanical properties and thermal stability of poly(lactic acid) toughened by precipitated barium sulfate

Russian Journal of Physical Chemistry A ◽

10.1134/s0036024415110242 ◽

2015 ◽

Vol 89 (11) ◽

pp. 2092-2096 ◽

Cited By ~ 7

Author(s):

Jinian Yang ◽

Chuang Wang ◽

Kaiyun Shao ◽

Guoxin Ding ◽

Yulun Tao ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Lactic Acid ◽

Barium Sulfate ◽

Poly Lactic Acid ◽

Thermal Stability Of

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Thermal and Mechanical Properties of Mulch Film from Poly(Lactic Acid)/Expoxidized Natural Rubber Blends Filled with Rutile TiO2 as Fillers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.844.65 ◽

2013 ◽

Vol 844 ◽

pp. 65-68

Author(s):

Pranee Nuinu ◽

Kittikorn Samosorn ◽

Kittisak Srilatong ◽

Siripa Tongbut ◽

Sayant Saengsuwan

Keyword(s):

Thin Film ◽

Mechanical Properties ◽

Thermal Stability ◽

Lactic Acid ◽

Thermal Properties ◽

Natural Rubber ◽

Decomposition Temperature ◽

Poly Lactic Acid ◽

Thermal And Mechanical Properties ◽

Thermal Stability Of

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.

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Study on the Mechenical Properties of PPC/PLA Blends Modified by POSS

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.741.28 ◽

2013 ◽

Vol 741 ◽

pp. 28-32 ◽

Cited By ~ 2

Author(s):

Yi Chen ◽

Yue Peng ◽

Wen Yong Liu ◽

Guang Sheng Zeng ◽

Xiang Gang Li ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Tensile Strength ◽

Lactic Acid ◽

Impact Strength ◽

Rheological Properties ◽

Poly Lactic Acid ◽

Melt Blending ◽

Aliphatic Polycarbonate ◽

Thermal Stability Of

Aliphatic polycarbonate Polycarbonate/poly (lactic acid)/(PPC/PLA) blends were prepared by melt blending, 1,2-propanediol isobutyl POSS (P-POSS) were added into the blends as a compatilizer and reinforcer. The morphologies, mechanical properties and rheological properties of blends were investigated systematically. The results showed that the adding of P-POSS could improve the compatibilization of PPC and PLA obviously. The thermal stability of the blends was enhanced but the crystallization was effected slightly. Moreover, the tensile strength and impact strength of blends exhibited a considerably increase.

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The Mechanical Characteristics of Straw/poly(Lactic Acid) Composite Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.153 ◽

2011 ◽

Vol 335-336 ◽

pp. 153-156

Author(s):

Xue Li Wu ◽

Jian Hui Qiu ◽

Lin Lei ◽

Yang Zhao ◽

Eiichi Sakai

Keyword(s):

Thermal Stability ◽

Grain Size ◽

Lactic Acid ◽

Mechanical Characteristics ◽

Fracture Strain ◽

Filler Content ◽

Agricultural Wastes ◽

Poly Lactic Acid ◽

Effective Utilization ◽

Thermal Stability Of

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.

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Morphology, Mechanical and Thermal Properties of Poly(Lactic Acid)/Propylene-Ethylene Copolymer/Cellulose Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.972.172 ◽

2019 ◽

Vol 972 ◽

pp. 172-177

Author(s):

Sirirat Wacharawichanant ◽

Patteera Opasakornwong ◽

Ratchadakorn Poohoi ◽

Manop Phankokkruad

Keyword(s):

Thermal Stability ◽

Lactic Acid ◽

Thermal Properties ◽

Tensile Stress ◽

Cellulose Fibers ◽

Phase Morphology ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Ethylene Copolymer ◽

Thermal Stability Of

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.

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Morphology and Properties of Poly(Lactic Acid)/Ethylene-Octene Copolymer Blends with Different Organoclay Types

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.837.174 ◽

2020 ◽

Vol 837 ◽

pp. 174-180

Author(s):

Sirirat Wacharawichanant ◽

Attachai Sriwattana ◽

Kulaya Yaisoon ◽

Manop Phankokkruad

Keyword(s):

Thermal Stability ◽

Lactic Acid ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Two Phase ◽

Copolymer Blends ◽

Ethylene Octene Copolymer ◽

Surface Modified ◽

Thermal Stability Of ◽

Observation Results

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.

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