Effects of Aspect Ratio of Carbon Nanotubes on Crystallization Behavior of Polylactide Composites

<div><div><div><p>Nanocomposites based on poly(ethylene terephthalate-ethylene dilinoleate) (PET-DLA) copolymers of different hard to soft segment ratios (40:60 and 60:40) and three different carbon nanofillers of different aspect ratios (dimensions), as 0D carbon black, 1D multiwalled carbon nanotubes, and 2D graphene, have been prepared in situ during two-stage polymerization. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the chemical structures of the obtained nanocomposites. Scanning electron microscopy (SEM) indicated very good dispersions of all carbon nanofillers in both polymer matrices. Differential scanning calorimetry (DSC) results revealed that the addition of nano-sized fillers eliminated cold crystallization of materials containing 40% hard segments in polymer matrix. We found that the high aspect ratio, 1D nano-filler (multiwalled carbon nanotubes) strongly nucleated crystallization of materials containing 60% of hard segments. This nanofiller also yielded the greatest improvement in the Young’s modulus as assessed by tensile tests, both at 24 oC and 37 oC. We did not observe reduced bacterial adhesion to nanocomposites, likely due to increased roughness. Importantly, in vitro cytocompatibility tests with L929 murine fibroblasts demonstrated cell viability and growth on all materials except those containing carbon nanotubes. Finally, both high aspect ratio nanofillers markedly improved the barrier properties of obtained nanocomposites. New materials were successfully used for manufacturing of prototype of heart assist device, with pneumatic membrane made of graphene nanocomposite.</p></div></div></div>

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The effects of nano-sized carbon fillers on the physico-chemical, mechanical, and biological properties of polyester nanocomposites

10.26434/chemrxiv.6300095.v2 ◽

2018 ◽

Author(s):

Zygmunt Staniszewski ◽

Peter Sobolewski ◽

Agnieszka Piegat ◽

Miroslawa El Fray

Keyword(s):

Carbon Nanotubes ◽

Aspect Ratio ◽

Multiwalled Carbon Nanotubes ◽

High Aspect Ratio ◽

Soft Segment ◽

Multiwalled Carbon ◽

Chemical Structures ◽

Aspect Ratios ◽

Hard Segments ◽

Carbon Nanofillers

<div><div><div><p>Nanocomposites based on poly(ethylene terephthalate-ethylene dilinoleate) (PET-DLA) copolymers of different hard to soft segment ratios (40:60 and 60:40) and three different carbon nanofillers of different aspect ratios (dimensions), as 0D carbon black, 1D multiwalled carbon nanotubes, and 2D graphene, have been prepared in situ during two-stage polymerization. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the chemical structures of the obtained nanocomposites. Scanning electron microscopy (SEM) indicated very good dispersions of all carbon nanofillers in both polymer matrices. Differential scanning calorimetry (DSC) results revealed that the addition of nano-sized fillers eliminated cold crystallization of materials containing 40% hard segments in polymer matrix. We found that the high aspect ratio, 1D nano-filler (multiwalled carbon nanotubes) strongly nucleated crystallization of materials containing 60% of hard segments. This nanofiller also yielded the greatest improvement in the Young’s modulus as assessed by tensile tests, both at 24 oC and 37 oC. We did not observe reduced bacterial adhesion to nanocomposites, likely due to increased roughness. Importantly, in vitro cytocompatibility tests with L929 murine fibroblasts demonstrated cell viability and growth on all materials except those containing carbon nanotubes. Finally, both high aspect ratio nanofillers markedly improved the barrier properties of obtained nanocomposites. New materials were successfully used for manufacturing of prototype of heart assist device, with pneumatic membrane made of graphene nanocomposite.</p></div></div></div>

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Experimental and theoretical investigation on the non-isothermal crystallization kinetics of polypropylene reinforced with multiwalled carbon nanotubes

Materials Today Proceedings ◽

10.1016/j.matpr.2020.04.137 ◽

2020 ◽

Vol 33 ◽

pp. 2264-2273

Author(s):

S. Sruthi ◽

R. Abhilash ◽

K. Tharun ◽

P. Gopi Krishna ◽

K. Jayanarayanan ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Crystallization Kinetics ◽

Theoretical Investigation ◽

Isothermal Crystallization ◽

Multiwalled Carbon ◽

Isothermal Crystallization Kinetics ◽

Kinetics Of

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Effect of Functionalized MWCNTs with Surfactant and Coupling Agent on Properties of LDPE/POE Blends

Journal of Elastomers & Plastics ◽

10.1177/0095244311413439 ◽

2011 ◽

Vol 43 (6) ◽

pp. 543-558 ◽

Cited By ~ 1

Author(s):

Z. Chen ◽

S. Chen ◽

J. Zhang

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Tensile Strength ◽

Multiwalled Carbon Nanotubes ◽

Crystallization Behavior ◽

Low Density Polyethylene ◽

Favorable Effect ◽

Low Density ◽

Multiwalled Carbon ◽

Polyolefin Elastomer

The surfactant, sodium dodecylbenzenesulfonate (NaDDBS) and coupling agents, γ-aminopropyltriethoxy sliane (KH550) and isopropyl dioleic(dioctylphosphate) titanate (NDZ101) were used to treat multiwalled carbon nanotubes in this work. The effects of surface modification of multiwalled carbon nanotubes on crystallization behavior, mechanical properties, and electrical properties of low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites were studied. The results showed that NaDDBS, KH550, and NDZ101 had a favorable effect of improving the dispersion of multiwalled carbon nanotubes, but it cannot improve the interfacial interactionbetween multiwalled carbon nanotubes and the matrix. The improvement in dispersion favored the crystallization behavior and mechanical properties. Modified multiwalled carbon nanotubes had a better acceleration nucleation effect than raw multiwalled carbon nanotubes on low density polyethylene/polyolefin elastomer blends at low content (≤1 wt%). The tensile strength of low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites with modified multiwalled carbon nanotubes increased with lower multiwalled carbon nanotubes content (≤1 wt%), and KH550 and NDZ101 led low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites to possess a higher tensile strength than that of NaDDBS with 1 wt% content. NaDDBS, KH550, and NDZ101 had a minor influence on the dielectric properties of the composites and even caused a decrease in the dielectric loss of composites with 10 wt% multiwalled carbon nanotubes content.

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