Crystallization behavior, mechanical properties, and enzymatic degradation of biosourced poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/graphene nanocomposites

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

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Enhancement of the Mechanical Properties of PEBAX Graphene Nanocomposite Using Supercritical Fluid Assisted Extrusion Polymer Processing Technique

Materials Science Forum ◽

10.4028/www.scientific.net/msf.883.75 ◽

2017 ◽

Vol 883 ◽

pp. 75-84 ◽

Cited By ~ 3

Author(s):

Nireeksha Karode ◽

Laurence Fitzhenry ◽

Siobhán Matthews ◽

Philip Walsh ◽

Austin Coffey

Keyword(s):

Mechanical Properties ◽

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

Mechanical Performance ◽

Mechanical Analysis ◽

Polymer Processing ◽

Processing Technique ◽

Graphene Nanocomposites ◽

Mechanical Tensile ◽

Supercritical Carbon

Medical tubing used in minimally invasive devices presents a number of design considerations depending on the material used, design requirements (such as sufficient stiffness, flexibility and biocompatibility) and processing conditions. Currently, manufacturing industries adopt co-extrusion systems to meet design specifications, by using multilayer configuration leading to higher cost per device and increased complexity. This paper investigates the mechanical performance of nanocomposites using supercritical carbon dioxide assisted polymer processing technique. The use of innovative medical compounds such as PEBAX graphene nanocomposites have resulted in measurable improvements in mechanical properties. This study also presents the effect of supercritical carbon dioxide on the mechanical and physical properties of the polymer matrix. The mechanical properties have been investigated using dynamic mechanical analysis (DMA) and mechanical tensile test, where sufficient reinforcement was observed depending on the composition of graphene within PEBAX matrix. ATR-FTIR was used to further analyze the effect of supercritical carbon dioxide and interactions within the polymer composite matrix.

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Impact of the processing temperature on the crystallization behavior and mechanical properties of poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)]

Polymer ◽

10.1016/j.polymer.2021.123987 ◽

2021 ◽

pp. 123987

Author(s):

Julie Bossu ◽

Nicolas Le Moigne ◽

Philippe Dieudonné-George ◽

Loïc Dumazert ◽

Valérie Guillard ◽

...

Keyword(s):

Mechanical Properties ◽

Crystallization Behavior ◽

Processing Temperature

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Research on compatibility and surface of high impact bio-based polyamide

High Performance Polymers ◽

10.1177/09540083211005511 ◽

2021 ◽

pp. 095400832110055

Author(s):

Yang Wang ◽

Yuhui Zhang ◽

Yuhan Xu ◽

Xiucai Liu ◽

Weihong Guo

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Scanning Electron Microscopy ◽

Differential Scanning Calorimetry ◽

Crystallization Behavior ◽

High Impact ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

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Mechanical properties and toughening mechanisms of epoxy/graphene nanocomposites

Journal of Polymer Engineering ◽

10.1515/polyeng-2014-0134 ◽

2015 ◽

Vol 35 (3) ◽

pp. 257-266 ◽

Cited By ~ 10

Author(s):

Rahim Eqra ◽

Kamal Janghorban ◽

Habib Daneshmanesh

Keyword(s):

Mechanical Properties ◽

Fracture Surface ◽

Flexural Strength ◽

Young’S Modulus ◽

Young's Modulus ◽

Graphene Nanosheets ◽

Flexural Modulus ◽

Mechanical Tests ◽

Toughening Mechanism ◽

Graphene Nanocomposites

Abstract Because of extraordinary physical, chemical and mechanical properties, graphene nanosheets (GNS) are suitable fillers for optimizing the properties of different polymers. In this research, the effect of GNS content (up to 1 wt.%) on tensile and flexural properties, morphology of fracture surface, and toughening mechanism of epoxy were investigated. Results of mechanical tests showed a peak for tensile and flexural strength of samples with 0.1 wt.% GNS such that the tensile and flexural strength improved by 13% and 3.3%, respectively. The Young’s modulus and flexural modulus increased linearly with GNS content, although the behavior of the Young’s modulus was more remarkable. Morphological investigations confirmed this behavior because the GNS dispersion in the epoxy matrix was uniform at lower contents and agglomerated at higher contents. Finally, microscopical observation showed that the major toughening mechanism of graphene-epoxy nanocomposites was crack path deflection, which changed the mirror fracture surface of the pure epoxy to rough surface.

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Effects of Glycerol and Tween 60 on the Crystallization Behavior, Mechanical Properties, and Microstructure of a Plastic Fat

Crystal Growth & Design ◽

10.1021/cg034136v ◽

2004 ◽

Vol 4 (1) ◽

pp. 161-168 ◽

Cited By ~ 26

Author(s):

Jerrold W. Litwinenko ◽

Anand Pal Singh ◽

Alejandro G. Marangoni

Keyword(s):

Mechanical Properties ◽

Crystallization Behavior ◽

Tween 60 ◽

Plastic Fat

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Mechanical properties and adhesive behavior of epoxy-graphene nanocomposites

International Journal of Adhesion and Adhesives ◽

10.1016/j.ijadhadh.2017.12.004 ◽

2018 ◽

Vol 84 ◽

pp. 119-125 ◽

Cited By ~ 38

Author(s):

C. Salom ◽

M.G. Prolongo ◽

A. Toribio ◽

A.J. Martínez-Martínez ◽

I. Aguirre de Cárcer ◽

...

Keyword(s):

Mechanical Properties ◽

Graphene Nanocomposites

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Crystallization behavior, Al-Ce intermetallic formation, and microstructure refinement of near-eutectic Al–Si alloys by rare-earth element additions

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1111108 ◽

2020 ◽

Vol 111 (11) ◽

pp. 938-952

Author(s):

Bo Chi ◽

Zhiming Shi ◽

Cunquan Wang ◽

Liming Wang ◽

Hao Lian ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Rare Earth ◽

Rare Earth Element ◽

Crystallization Behavior ◽

Earth Element ◽

Microstructural Refinement ◽

Preferential Growth ◽

Intermetallic Formation ◽

The Matrix

Abstract Near-eutectic Al-Si alloys have low strength and high brittleness because of the presence of many eutectic b-Si flakes, needle-like Al-Fe-Si intermetallics, and coarse α-Al grains. This study disclosed the effects of cerium-rich RE (rare earth) element modification on orientation characters of crystals, formation of Al-Ce compounds, and microstructural refinement to improve the microstructure and mechanical properties of the alloys. The RE addition depressed preferential growth along the close-packed and/or sub-closepacked planes and promoted growth along the non-closepacked planes, in which La and other elements were dissolved into needle-like Al11Ce3 phase. When the temperature decreased, Al11Ce3 was preferentially crystallized from the melts and then devitrified by attaching to the surface of β-Al5FeSi needles. Moreover, many small Al11Ce3 particles were precipitated in the matrix and on the Si surface by a T6 heat treatment. Eutectic β-Si phases were constructed into discontinuous networks, short rods, and even particles by RE additions, which were further transformed into fine nodules following the T6 treatment. α-Al grains and primary β-Al5FeSi needles were simultaneously refined. The addition of 1.0 wt.% REs and subsequent T6 treatment yielded the highest tensile strength, elongation, and hardness of the alloy.

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