Hybrid Nanocomposites of Poly(Lactic Acid)/Thermoplastic Polyurethane with Nanosilica/Montmorillonite

2019 ◽  
Vol 947 ◽  
pp. 77-81
Author(s):  
Natsuda Palawat ◽  
Phasawat Chaiwutthinan ◽  
Sarintorn Limpanart ◽  
Amnouy Larpkasemsuk ◽  
Anyaporn Boonmahitthisud

The aim of this study is to improve the physical properties of poly(lactic acid) (PLA) by incorporating thermoplastic polyurethane (TPU), organo-montmorillonite (OMMT) and/or nanosilica (nSiO2). PLA was first melt mixed with five loadings of TPU (10–50 wt%) on a twin-screw extruder, followed by injection molding. The addition of TPU was found to increase the impact strength, elongation at break and thermal stability of the blends, but decrease the tensile strength and Young’s modulus. Based on a better combination of the mechanical properties, the 70/30 (w/w) PLA/TPU blend was selected for preparing both single and hybrid nanocomposites with a fix total nanofiller content of 5 parts per hundred of resin (phr), and the OMMT/nSiO2 weight ratios were 5/0, 2/3, 3/2 and 0/5 (phr/phr). The Young’s modulus and thermal stability of the nanocomposites were all higher than those of the neat 70/30 PLA/TPU blend, but at the expense of reducing the tensile strength, elongation at break and impact strength. However, all the nanocomposites exhibited higher impact strength and Young’s modulus than the neat PLA. Among the four nanocomposites, a single-filler nanocomposite containing 5 phr nSiO2 exhibited the highest impact strength and thermal stability, indicating that there was no synergistic effect of the two nanofillers on the investigated physical properties. However, the hybrid nanocomposite containing 2/3 (phr/phr) OMMT/nSiO2 possessed a compromise in the tensile properties.

2020 ◽  
Vol 845 ◽  
pp. 39-44
Author(s):  
Woraporn Kiwjaroun ◽  
Saowaroj Chuayjuljit ◽  
Phasawat Chaiwutthinan ◽  
Anyaporn Boonmahitthisud

The aim of this study is to prepare green composites from poly (lactic acid) (PLA) and in-house epoxidized natural rubber (ENR) with coir fibers (CFs). In-house ENR with medium epoxidation degree (about 35 mole% epoxidation) was first prepared via ‘in situ’ epoxidation of natural rubber latex. PLA was melt-mixed with three loadings (10, 20 and 30 wt%) of ENR on a twin-screw extruder, followed by injection molding to observe their mechanical properties (impact strength, tensile strength, Young’s modulus and elongation at break) and thermal stability. The results showed that the addition of the ENR enhanced the impact strength and elongation at break, but deteriorated tensile strength, Young’s modulus and thermal stability of the blends. From mechanical properties consideration, the 90/10 PLA/ENR blend was selected for preparing green composites with different amounts of CFs (5, 10 and 20 phr). It was found that the incorporation of CFs improved tensile strength and Young’s modulus. However, the impact strength, elongation at break and thermal stability of the green composites decreased as compared to those of the neat 90/10 PLA/ENR blend.


2011 ◽  
Vol 410 ◽  
pp. 51-54 ◽  
Author(s):  
Arpaporn Teamsinsungvon ◽  
Yupaporn Ruksakulpiwat ◽  
Kasama Jarukumjorn

Poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend and its composite were prepared by melt blending method. Maleic anhydride grafted PLA (PLA-g-MA) prepared in-house was used as a compatibilizer to enhance the interfacial adhesion between PLA and PBAT and also to improve the dispersion of calcium carbonate (CaCO3) in polymer matrices. Increasing PBAT content (10-30 wt%) resulted in the improvement of elongation at break and impact strength of PLA. Tensile strength, Young’s modulus, and impact strength of PLA/PBAT blend improved with the presence of PLA-g-MA due to enhanced interfacial adhesion between PLA and PBAT. As CaCO3 (5 wt%) was incorporated into the compatibilized blend, tensile strength, Young’s modulus, and impact strength insignificantly changed while elongation at break decreased.


2011 ◽  
Vol 347-353 ◽  
pp. 1778-1781
Author(s):  
Zheng Hua Song ◽  
T Ruphun ◽  
T Karnjanamayul

Pottery stone (PTS) filled polypropylene (PP) composites were prepared using a twin screw extruder and injection molding machine. PTS used in this study is in a particulate form with an average particle size of 6.95 μm. The melt flow index (MFI), tensile properties (tensile strength, Young’s modulus and elongation at break), notched-impact strength, flexural strength, thermal stability and morphology of the PP/PTS composites were investigated. The results showed that the incorporation of PTS into the PP matrix caused a slight decrease in the MFI, an increase in the tensile strength (5 and 10 phr, but 10 phr optimal), Young’s modulus (all, but 20 phr optimal), impact strength (all, but 20 phr optimal), flexural strength (all, but 10 phr optimal) and thermal stability (all, but 20 phr optimal) and a decrease in the elongation at break. Therefore, PTS can be effectively used as reinforcing filler in PP. The fractured surfaces of the composites displayed the well dispersed of PTS in PP matrix and also exhibited plastic deformation feature.


2019 ◽  
Vol 953 ◽  
pp. 47-52
Author(s):  
Sirirat Wacharawichanant ◽  
Attachai Sriwattana ◽  
Kulaya Yaisoon ◽  
Manop Phankokkruad

The effects of the montmorillonite clay surface modified with 0.5-5 wt% aminopropyltriethoxysilane and 15-35% octadecylamine (Clay-APTSO) on morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/ethylene-octene copolymer (EOC)/Clay-APTSO composites were investigated. The blends of PLA/EOC with and without Clay-APTSO were prepared by melt mixing in an internal mixer. Scanning electron microscopy analysis observed the morphology of PLA/EOC blends demonstrated a phase separation of minor phase and matrix phase. The addition of Clay-APTSO in PLA/EOC blends showed significant decreased in droplet size of dispersed EOC phase, thus, Clay-APTSO acted as an effective compatibilizer in the PLA/EOC blends. The results of tensile properties found the decrease of Young’s modulus of PLA when added EOC due to the low modulus and flexibility of EOC. While the incorporation of Clay-APTSO increased significantly Young’s modulus of PLA/EOC blends at low EOC and Clay-APTSO content. The strain at break of the blends increased with the increase of EOC loading, this indicated the presence of EOC enhanced the elongation at break of PLA, while the addition Clay-APTSO reduced the strain at break of PLA/EOC blends. The tensile strength of all blend compositions improved when added Clay-APTSO and the tensile strength showed the highest value at 3 phr of Clay-APTSO. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-APTSO in the blends could improve the thermal stability of the PLA/EOC blends.


2012 ◽  
Vol 488-489 ◽  
pp. 691-695
Author(s):  
Saowaroj Chuayjuljit ◽  
Thitima Rupunt

The focus of this study is to investigate the influences of ethylene octene copolymer (EOC) and carbon nanotubes (CNTs) on the mechanical properties (tensile and flexural properties) and thermal stability of polypropylene (PP)-based thermoplastic elastomer nanocomposites. The PP/EOC blends were prepared at two different weight ratios, 80/20 and 70/30 (w/w) PP/EOC, and each blend was compounded with a very low loading of CNTs (0.5-2 parts by weight per hundred of the PP/EOC resin). Both PP/EOC blends exhibited a higher elongation at break but a lower tensile strength, Young’s modulus and flexural strength as compared with those of the neat PP. However, the addition of CNTs caused a slightly change in the tensile strength and flexural strength but a more significant change in the Young’s modulus and elongation at break. The Young’s modulus and elongation at break of the PP/EOC blends were improved by filling with the appropriate loading of the CNTs. Thus, the combined use of EOC and CNTs can provide the balanced mechanical properties to the PP. Moreover, thermogravimetric analysis showed an improvement in the thermal stability of PP by the presence of both EOC and CNTs.


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.


2012 ◽  
Vol 488-489 ◽  
pp. 945-949 ◽  
Author(s):  
Saowaroj Chuayjuljit ◽  
Thatisorn Karnjanamayul

In this study, tensile properties, thermal stability and morphology of polypropylene/ethylene propylene diene rubber/wollastonite (PP/EPDM/wollastonite) thermoplastic elastomer composites were tested and evaluated as a function of their compositions in comparison with PP/EPDM blends and native PP. PP was melt mixed with two loadings of EPDM (20 and 30% (w/w)) and for the composites each of these with three loadings of wollastonite (10, 20 and 30 parts by weight per hundred of the PP/EPDM resin) on a twin screw extruder and then injection molded. Both PP/EPDM blends provided a higher elongation at break but a lower tensile strength and Young’s modulus as compared with those of the neat PP. However, the addition of wollastonite microparticles (particle size of 1200 mesh) into the blends increased the Young’s modulus in a dose-dependent manner with increasing wollastonite loadings, whilst the tensile strength and elongation at break were decreased. Moreover, the thermal stability was improved by the presence of either EPDM or wollastonite in the PP matrix.


2019 ◽  
pp. 089270571987823 ◽  
Author(s):  
Md RH Mazumder ◽  
F Numera ◽  
A Al-Asif ◽  
M Hasan

Present research investigates the effect of bentonite clay and polypropylene (PP) matrix on the properties of silk and glass fiber hybrid composites. Three types of composite were prepared with 10 wt% silk and fiber at 1:1 ratio using hot press machine. In two composites commercial and recycled PP were used as matrix, while in third composite bentonite clay was added to silk and glass-reinforced commercial PP. Mechanical (tensile, flexural, impact, and hardness) tests, water absorption test, and thermogravimetric analysis were subsequently conducted. Tensile strength, flexural modulus, and hardness decreased, whereas Young’s modulus, impact strength, water absorption, and thermal stability increased with the addition of bentonite clay. On the other hand, change of matrix from commercial PP to recycled PP increased Young’s modulus, flexural strength, impact strength, and thermal stability and decreased tensile strength, flexural modulus, and hardness.


2019 ◽  
Vol 253 ◽  
pp. 02005
Author(s):  
Daniel Gere ◽  
Tibor Czigany

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.


2018 ◽  
Vol 26 (8-9) ◽  
pp. 454-460 ◽  
Author(s):  
Ahmad Fikri Abdul Karim ◽  
Hanafi Ismail

Thermoplastic elastomer composites of polystyrene (PS) blended with styrene–butadiene rubber (SBR)–filled wollastonite were prepared using a laboratory scale internal mixer. The compatibiliser used in this study was maleic anhydride (MAH). The torque developments, morphology, and mechanical properties such as tensile strength, elongation at break, Young’s modulus and impact strength were studied. PS/SBR/wollastonite composites with the addition of MAH had higher torque than PS/SBR/wollastonite composites without MAH. Tensile strength, impact strength and elongation at break were reduced by increasing filler loading, both for composites with and without MAH. Composites with MAH had higher tensile strength but lower impact strength and elongation at break as compared with composites without MAH. The Young’s modulus increased with the wollastonite loading, whereas at a similar wollastonite loading, composites with MAH exhibited higher values of Young’s modulus than composites without MAH. Scanning electron microscopy on fracture surfaces showed better filler–matrix adhesion for composites with MAH.


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