scholarly journals Effect of Melt Mixing Time in Internal Mixer on Mechanical Properties and Crystallization Behavior of Glycidyl Methacrylate Grafted Poly (Lactic Acid)

2015 ◽  
Vol 03 (07) ◽  
pp. 102-107
Author(s):  
Nguyen Chi Thanh ◽  
Chaiwat Ruksakulpiwat ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Glycidyl Methacrylate ◽  
Crystallization Behavior ◽  
Mixing Time ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Internal Mixer

Effect of Glycidyl Methacrylate (GMA) Content on Grafting Yield and Mechanical Properties of GMA Grafted Poly(Lactic Acid) Prepared by Melt Mixing Method

2016 ◽  
Vol 709 ◽  
pp. 27-31
Author(s):  
Thanh Chi Nguyen ◽  
Ruksakulpiwat Chaiwat ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Glycidyl Methacrylate ◽  
Fracture Behaviour ◽  
Industrial Applications ◽  
Proton Nuclear Magnetic Resonance ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Molecular Weights ◽  
Grafting Reaction

Glycidyl methacrylate (GMA) was grafted onto poly (lactic acid) (PLA) by internal mixer using dicumyl peroxide (DCP) as an initiator. The results from proton nuclear magnetic resonance (1H-NMR) and gel permeation chromatograph (GPC) indicated that the grafting reaction of GMA onto PLA took place successfully. In order to obtain the optimal GMA content used to graft onto PLA chain, the GMA content was varied into 5, 10 and 15 wt% of PLA. GMA content of 10 wt% was found to give the highest elongation at break of glycidyl methacrylate grafted poly (lactic acid) (PLA-g-GMA). The weight-average molecular weights, the number-average molecular weights and polydispersity index of PLA increased after grafting with GMA. After grafting, the brittle fracture behaviour of PLA was changed to ductile fracture behaviour of PLA-g-GMA. With its superior mechanical properties compared to those of pure PLA, PLA-g-GMA can be considered to be used as a new generation of biodegradable polymer, which can be applied in many industrial applications.

Comparison of Morphology and Mechanical Properties of Polyoxymethylene/Cellulose and Poly(Lactic Acid)/Cellulose Composites

2018 ◽  
Vol 916 ◽  
pp. 19-23 ◽  
Author(s):  
Sirirat Wacharawichanant ◽  
Nisarat Wimonsupakit ◽  
Sasithorn Kuhaudomlap
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Cellulose Composites ◽  
Internal Mixer ◽  
The Impact ◽  
Morphology And Mechanical Properties

The objective of this study is to fabricate the polyoxymethylene (POM)/microcrystalline cellulose (MCC) and poly(lactic acid) (PLA)/MCC composites, and to compare the effect of MCC on the morphology and mechanical properties of POM and PLA. The polymer composites were prepared by melt mixing in an internal mixer and molded by compression molding. The MCC concentrations were 1, 3, 5, 7, 10, 15 and 10% by weight. From scanning electron microscopy study observes the fracture surface of POM and PLA composites is much rough and the roughness increases with increasing MCC content. This observation indicates MCC induces the ductile fracture characteristic of POM and PLA. The addition of MCC can improve the impact strength of PLA composite and improve Young’s modulus of both POM and PLA composites. While the tensile strength and strain at break decrease after adding MCC. In summary, MCC can enhance the morphology and mechanical properties of PLA composites is better than POM composites.

Response of Modified Poly(lactic acid) to Microwave Radiation

2012 ◽  
Vol 488-489 ◽  
pp. 1393-1397
Author(s):  
Buranin Saengiet ◽  
Wasin Koosomsuan ◽  
Phassakarn Paungprasert ◽  
Rattikarn Khankrua ◽  
Sumonman Naimlang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Microwave Radiation ◽  
Food Packaging ◽  
Impact Resistance ◽  
Poly Lactic Acid ◽  
Polypropylene Glycol ◽  
Heat Accumulation ◽  
The One ◽  
Internal Mixer

The frozen instant food packaging is the one of disposal product, which produced from petroleum–based plastic and has been accumulated worldwide pressuring on the environment. Therefore, the biodegradable plastics have become key candidates in this application. Poly(lactic acid) (PLA) was regarded as one of the most promising biodegradable polymer due to its good mechanical properties. The aim of this work was to study on the freezability and microwavability of PLA through crosslink reaction. For the improvement of the processibility of PLA, hyperbranched polymer (HBP) and polypropylene glycol (PPG) were used as plasticizer. Then the crosslinking of PLA was introduced by addition of peroxide (Luperox101) and triallyl isocyanurate (TAIC) in an internal mixer. Neat and modified PLA samples were characterized and testing for mechanical properties. From the gel content results, it was showed the increased value with the increased content of TAIC due to the denser crosslinked structure of polymer. This result was confirmed by FT-IR spectra. All modified PLA samples showed the higher %strain at break than neat PLA. In addition, impact resistance in frozen state showed the results of modified PLA with 0.1wt% of peroxide and 0.15 wt% of TAIC, was higher than neat PLA. Moreover, this composition also showed the highest microwave response and heat accumulation was suppressed when the specimen was immersed in the water during the test. From the results obtained in this work, the further investigation is needed to pursue and elucidate the relationship between the polymer structure and heat absorption when materials undergo the microwave radiation.

Effect of cellulose nanofibers from cassava pulp on physical properties of poly(lactic acid) biocomposites

2019 ◽  
Vol 33 (8) ◽  
pp. 1094-1108
Author(s):  
Thanh Chi Nguyen ◽  
Chaiwat Ruksakulpiwat ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanofibers ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Melt Mixing ◽  
Cassava Pulp ◽  
Lower Temperature ◽  
Alkali Hydrolysis ◽  
Internal Mixer

Biocomposites of poly(lactic acid) (PLA) and cellulose nanofibers (CNFs) extracted from cassava pulp were successfully prepared by melt mixing in an internal mixer. CNFs were prepared from cassava pulp by submitting to alkali hydrolysis, bleaching treatment, and acid hydrolysis. The compatibility between CNFs and PLA matrix was improved using glycidyl methacrylate (GMA) grafted PLA (PLA-g-GMA) as an effective compatibilizer. Higher elongation at break and impact strength of PLA/PLA-g-GMA/CNFs biocomposites was achieved compared to that of neat PLA. PLA-g-GMA shows a strong effect on the crystallization behavior of the biocomposites. The PLA/PLA-g-GMA/CNFs biocomposites induce cold crystallization to take place at lower temperature. Higher degree of crystallinity of PLA/PLA-g-GMA/CNFs biocomposites was obtained compared to PLA/CNFs biocomposites. The mechanical and thermal properties of PLA/CNFs biocomposites at various ratios were investigated. With increasing CNFs contents, the modulus of the biocomposites increases. Thermal stability of PLA/CNFs and PLA/PLA-g-GMA/CNFs biocomposites did not change significantly compared to that of neat PLA.

Crystallization behavior and mechanical properties of poly(lactic acid) complex fiber toughened by carbon nanotube nanocapsules

2017 ◽  
Vol 88 (14) ◽  
pp. 1616-1627 ◽  
Author(s):  
Shu-qiang Liu ◽  
Gai-hong Wu ◽  
Yun-chao Xiao ◽  
Hong-xia Guo ◽  
Fen-juan Shao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Carbon Nanotube ◽  
Crystallization Behavior ◽  
Poly Lactic Acid ◽  
Acid Complex ◽  
Main Obstacle ◽  
Industrial Areas

Poly(lactic acid) (PLA) fiber, owing to its biocompatibility and biodegradability, could be widely used in many related industrial areas. However, high brittleness has been the main obstacle to expanding its applications. So in this paper, carbon nanotube (CNT) nanocapsules were designed to toughen PLA and further reported their effect on the crystallization behavior and mechanical properties of PLA complex fiber. These designed CNT nanocapsules successfully solved the agglomeration of CNTs within the PLA matrix as well as the compatibility issue. In addition, the morphological, mechanical, optical and thermal properties of PLA complex fibers were also studied. The addition of CNT nanocapsules obviously improved the crystallization behavior of PLA fiber. Furthermore, compared with pure PLA, the tensile strength of PLA complex fiber was enhanced by 30.62% and the elongation by 32.2%, so the designed CNT nanocapsules could be used as a toughener for PLA fiber. This research benefits the extension of PLA applications where toughness is an important factor.

scholarly journals Barrier Properties and Hydrophobicity of Biodegradable Poly(lactic acid) Composites Reinforced with Recycled Chinese Spirits Distiller’s Grains

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2861
Author(s):  
Zhi-Jun Chen ◽  
Chi-Hui Tsou ◽  
Meng-Lin Tsai ◽  
Jipeng Guo ◽  
Manuel Reyes De Guzman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Control Group ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Distiller's Grains ◽  
The Matrix ◽  
Section Structure

Adding natural biomass to poly(lactic acid) (PLA) as a reinforcing filler is a way to change the properties of PLA. This paper is about preparing PLA/biomass composites by physically melting and blending Chinese Spirits distiller’s grains (CSDG) biomass and PLA to optimize the composite performance. Composites of modified PLA (MPLA) with varying amounts of CSDG were also prepared by the melt-mixing method, and unmodified PLA/CSDG composites were used as a control group for comparative analysis. The functional groups of MPLA enhanced the compatibility between the polymer substrate and CSDG. The composite water vapor/oxygen barrier and mechanical properties were studied. It was found that the barrier and mechanical properties of MPLA/CSDG composites were significantly improved. SEM was adopted to examine the tensile section structure of the composites, and the compatibility between the filler and the matrix was analyzed. An appropriate amount of CSDG had a better dispersibility in the matrix, and it further improved the interfacial bonding force, which in turn improved the composite mechanical properties. X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were conducted to determine the crystalline properties and to analyze the stability of the composites. It was found that the CSDG content had a significant effect on the crystallinity. Barrier and biodegradation mechanisms were also discussed.

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