scholarly journals Poly(Lactic Acid) Filled with Cassava Starch-g-Soybean Oil Maleate

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nopparut Kiangkitiwan ◽  
Kawee Srikulkit
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Soybean Oil ◽  
Interfacial Adhesion ◽  
Cassava Starch ◽  
Poly Lactic Acid ◽  
Starch Granules ◽  
Screw Extruder ◽  
Surface Appearance ◽  
Twin Screw

Poly(lactic acid), PLA, is a biodegradable polymer, but its applications are limited by its high cost and relatively poorer properties when compared to petroleum-based plastics. The addition of starch powder into PLA is one of the most promising efforts because starch is an abundant and cheap biopolymer. However, the challenge is the major problem associated with poor interfacial adhesion between the hydrophilic starch granules and the hydrophobic PLA, leading to poorer mechanical properties. In this paper, soybean oil maleate (SOMA) was synthesized by grafting soybean oil with various weight percents of maleic anhydride (MA) using dicumyl peroxide (DCP) as an initiator. Then, SOMA was employed for the surface modifying of cassava starch powder, resulting in SOMA-g-STARCH. The obtained SOMA-g-STARCH was mixed with PLA in various weight ratios using twin-screw extruder, resulting in PLA/SOMA-g-STARCH. Finally, the obtained PLA/SOMA-g-STARCH composites were prepared by a compression molding machines. The compatibility, thermal properties, morphology properties, and mechanical properties were characterized and evaluated. The results showed that the compatibility, surface appearance, and mechanical properties at 90 : 10 and 80 : 20 ratios of PLA/SOMA-g-STARCH were the best.

scholarly journals Properties of Poly(Lactic Acid) Filled with Hydrophobic Cellulose/SiO2 Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kittithorn Lertphirun ◽  
Kawee Srikulkit
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Hydrolytic Degradation ◽  
Poly Lactic Acid ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Hydrolysis Of Cellulose ◽  
One Step ◽  
Hydrolysis Of

Hydrophobic cellulose/SiO2 composites were prepared. Resultant hydrophobic cellulose/SiO2 composites were melt mixed with PLA using a twin-screw extruder to obtain 10 wt% masterbatch. Again, 10 wt% masterbatch was melt mixed with virgin PLA, resulting in PLA containing hydrophobic cellulose/SiO2 at various contents (1 wt%, 3 wt%, and 5 wt%) using a twin-screw extruder (barrel zone temperature: 150/160/170/180/190°C (die zone)). Injection-molded samples were prepared for mechanical properties evaluation. Results showed that poor mechanical properties found at low percent loadings were associated with a significant depolymerization of masterbatch composition due to twice thermal treatments. Note that 10 wt% masterbatch was subjected to injection molding straight away in a one-step process. Results showed that 10 wt% hydrophobic cellulose/SiO2/PLA composites exhibited mechanical properties equivalent to neat PLA. Importantly, the addition of hydrophobic cellulose/SiO2 at high percent loading could favor landfill degradation of PLA via water absorption ability of cellulose. It was expected that enzymatic hydrolysis of cellulose resulted in the formation of lactic acid and silicic acid which consequently catalyzed the hydrolytic degradation (acid hydrolysis) of PLA. The hydrolytic degradation produced carboxylic acid end group which further accelerated the degradation rate.

scholarly journals Mechanical Properties and Bioactivity of Poly(Lactic Acid) Composites Containing Poly(Glycolic Acid) Fiber and Hydroxyapatite Particles

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 249
Author(s):  
Han-Seung Ko ◽  
Sangwoon Lee ◽  
Doyoung Lee ◽  
Jae Young Jho
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flexural Strength ◽  
Interfacial Adhesion ◽  
Glycolic Acid ◽  
Compact Bone ◽  
Poly Lactic Acid ◽  
Coupling Reactions ◽  
The Poor ◽  
Human Compact Bone

To enhance the mechanical strength and bioactivity of poly(lactic acid) (PLA) to the level that can be used as a material for spinal implants, poly(glycolic acid) (PGA) fibers and hydroxyapatite (HA) were introduced as fillers to PLA composites. To improve the poor interface between HA and PLA, HA was grafted by PLA to form HA-g-PLA through coupling reactions, and mixed with PLA. The size of the HA particles in the PLA matrix was observed to be reduced from several micrometers to sub-micrometer by grafting PLA onto HA. The tensile and flexural strength of PLA/HA-g-PLA composites were increased compared with those of PLA/HA, apparently due to the better dispersion of HA and stronger interfacial adhesion between the HA and PLA matrix. We also examined the effects of the length and frequency of grafted PLA chains on the tensile strength of the composites. By the addition of unidirectionally aligned PGA fibers, the flexural strength of the composites was greatly improved to a level comparable with human compact bone. In the bioactivity tests, the growth of apatite on the surface was fastest and most uniform in the PLA/PGA fiber/HA-g-PLA composite.

Effect of Compatibilizers on Composite Materials of Bio-Ethanol Byproduct-Poly(lacticacid)

2012 ◽  
Vol 204-208 ◽  
pp. 4088-4092
Author(s):  
Ming Ming Zhang ◽  
Xiao Huan Liu ◽  
Chun Peng Wang ◽  
Li Wei Jin
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Composite Materials ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Twin Screw Extrusion ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Process Effects ◽  
Properties Of Composites

The blend composite materials of bio-ethanol byproduct-Poly(lactic acid) (PLA) were produced by a twin-screw extrusion process. Effects of bio-ethanol byproduct (BEB) contents and different compatibilizers on properties of composite materials were investigated. The research showed that with the increase of contents of bio-ethanol byproduct, the mechanical properties decreased. The mechanical properties of composites were improved by adding the compatibilizers, especially the polypropylene grafted maleic anhydride (PP-MAH). When the PP-MAH content was 2.5%, the mechanical properties of the composite materials were superior to others.

Composites of Poly(lactic Acid) with Rice Straw Fibers Modified by Poly(butyl Acrylate)

2011 ◽  
Vol 675-677 ◽  
pp. 357-360
Author(s):  
Li Jun Qin ◽  
Jian Hui Qiu ◽  
Ming Zhu Liu ◽  
Sheng Long Ding ◽  
Liang Shao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Rice Straw ◽  
Butyl Acrylate ◽  
Interfacial Adhesion ◽  
Suspension Polymerization ◽  
Water Solution ◽  
Poly Lactic Acid ◽  
Biodegradable Composites

The modified rice straw fibers (MRSF) were prepared by suspension polymerization technique of butyl acrylate (BA) monomer and rice straw fibers (RSF) in water solution. FTIR test indicated that PBA was coated and absorbed on RSF.The biodegradable composites were prepared with the MRSF and poly(lactic acid) (PLA) by HAAKE rheometer. Mechanical properties showed that the tensile strength of PLA/MRSF composites were (W (%) =7.98%) increased by 6 MPa compared with blank sample. The possible reason was that the good interfacial adhesion between PLA and MRSF, which was demonstrated by SEM.

Morphological, Thermal and Mechanical Properties of Poly(Lactic Acid)/Cellulose/ Nano-Clay Composite

2020 ◽  
Vol 856 ◽  
pp. 331-338
Author(s):  
Sirisart Ouajai ◽  
Suttinun Phongtamrug
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Poly Lactic Acid ◽  
Thermal And Mechanical Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Chemically Modified ◽  
Nano Clay ◽  
Twin Screw ◽  
Modified Cellulose

This research has focused on the effect of modified cellulose and clay on the thermal and mechanical properties of PLA bio-nanocomposite. Cellulose was chemically modified with silane coupling agent in order to enhance compatiblization with PLA. Successful modification was confirmed by Fourier Transform Infrared Spectroscopy and EDX-SEM. PLA was compounded with various amounts and ratios of the modified cellulose and clay by a twin-screw extruder. Thermal properties of the bio-nanocomposites were characterized by Thermogravimetric Analysis and Differential Scanning Calorimetry. Glass transition temperature of the bio-nanocomposite slightly decreased whereas melting temperature remained constant when the amount of both fillers was increased. In addition, crystallization behaviour of PLA has been influenced by the type and amount of the fillers. Clay showed a greater effect on the crystallization of PLA than the modified cellulose and unmodified one, respectively. The flexural modulus of the composite containing equal amount between clay and cellulose was increased with an increasing in fillers contents. But the flexural and impact strength of composite were gradually decreased with an increase in fillers contents. Variation of clay and cellulose ratio resulted in the change of mechanical properties. The composite containing higher ratio between clay:cellulose or cellulose:clay showed a better mechnical properties comparing to the ratio of clay:cellulose equal to 1:1.

Mechanical Properties of Poly(lactic acid) / Thermoplastic Starch Blends Crosslinked by Gamma Radiation

2013 ◽  
Vol 781-784 ◽  
pp. 467-470 ◽  
Author(s):  
Siriruck Kalapakdee ◽  
Thirawudh Pongprayoon ◽  
Kasinee Hemvichian ◽  
Phiriyatorn Suwanmala ◽  
Wararat Kangsumrith
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Gamma Radiation ◽  
Crosslinking Agent ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Optimum Dose ◽  
Gel Fraction ◽  
Twin Screw ◽  
Starch Blends

This research aims to determine the influences of radiation-induced crosslinking on the mechanical properties of polymer blends between poly (lactic acid) (PLA) and thermoplastic starch (TPS). PLA and TPS were mixed at different ratios (90:10, 80:20, 70:30, 60:40) in the presence of a crosslinking agent using a twin screw extruder. The blends were compression molded into films. The film samples were irradiated by gamma radiation at different doses. Gel fraction was used to determine crosslinking efficiency. Results showed that gamma radiation was able to induce crosslinking for PLA/TPS blends. The gel fraction and mechanical properties decreased with increasing TPS content. The optimum ratio of PLA:TPS with the maximum gel fraction and mechanical properties was 90:10 and the optimum dose was 40 kGy by gamma radiation.

Preparation and Characterization of Poly(Lactic Acid) (PLA)/Polyoxymethylene (POM) Blends

2018 ◽  
Vol 917 ◽  
pp. 3-6 ◽  
Author(s):  
Muhammad Haniff ◽  
Mohd Bijarimi ◽  
M.S. Zaidi ◽  
Ahmad Sahrim
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Chemical Analysis ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Twin Screw

PLA has limited applications due to its inherent brittleness, toughness and low elongation at break. One of the options for improvement is through blending with polyoxymethylene (POM). Melt blending of polylactic acid (PLA) and polyoxymethylene (POM) at 90/10 PLA/POM composition was carried out in a twin-screw extruder. The PLA/POM was loaded with 1 – 5 wt.% of nanoclay (Cloisite C20). The blends were then characterized for mechanical, morphological, chemical and thermal properties. It was found that tensile strength, Young's modulus, and elongation at break improved when the loadings of nanoclay were increased. Chemical analysis by FTIR revealed that PLA/POM blend is immiscible.

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