Effect of Surface Modified Cellulose Nanocrystal Fillers on the Mechanical Properties of Thiol-ene Photopolymerized Nanocomposites Using Diallyl Ether Monomer

Microcrystalline cellulose (MCC) was surface modified by two approaches, namely a plasma treatment in liquid using a Y-shaped tube for oxygen flow (MCC-P) and a TEMPO mediated oxidation (MCC-T). Both treatments led to the surface functionalization of cellulose as illustrated by FTIR and XPS results. However, TEMPO oxidation had a much stronger oxidizing effect, leading to a decrease of the thermal stability of MCC by 80 °C. Plasma and TEMPO modified celluloses were incorporated in a poly(3-hydroxybutyrate) (PHB) matrix and they influenced the morphology, thermal, and mechanical properties of the composites (PHB-MCC-P and PHB-MCC-T) differently. However, both treatments were efficient in improving the fiber–polymer interface and the mechanical properties, with an increase of the storage modulus of composites by 184% for PHB-MCC-P and 167% for PHB-MCC-T at room temperature. The highest increase of the mechanical properties was observed in the composite containing plasma modified cellulose although TEMPO oxidation induced a much stronger surface modification of cellulose. This was due to the adverse effect of more advanced degradation in this last case. The results showed that Y-shaped plasma jet oxidation of cellulose water suspensions is a simple and cheap treatment and a promising method of cellulose functionalization for PHB and other biopolymer reinforcements.

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Effect of Surface-Modified Si-Al-C® Fibre Addition on the Mechanical Properties of Silicon Carbide Composite

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.71.127 ◽

2010 ◽

Vol 71 ◽

pp. 127-132 ◽

Cited By ~ 2

Author(s):

H. Moriyasu ◽

J. Kita ◽

H. Suemasu ◽

Ian J. Davies ◽

S. Koda ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Silicon Carbide ◽

Specific Surface ◽

Acid Treatment ◽

Polar Solvent ◽

Sintering Aid ◽

C Fibre ◽

Surface Modified ◽

Effect Of Surface

The effect of surface modified Si-Al-C® fibre with carbon interface (SA/C fibre) addition on the densification of silicon carbide (SiC) composite was examined. An acid treatment (H2SO4 and HNO3) was carried out at 50°C for 3 h in order to add COO- group to the surface of SA/C fibre and to enhance the dispersibility of SA/C fibre in the SiC powder due to the mixing operation in the polar solvent. Commercially available ultrafine SiC powder (specific surface area: 47.5 m2∙g-1) was mixed with acid-treated SA/C fibre and sintering aid (4.8 mass% Al4C3 and 1.2 mass% B4C) in the presence of acetone. The relative density of the SiC composite with non-acid-treated SA/C fibre addition hot-pressed at 1800°C for 1 h in Ar atmosphere under a pressure of 62 MPa was 98.4%, whereas that of the SiC composite with acid-treated SA/C fibre addition increased to 98.7%. Furthermore, the fracture toughness increased from 5.6 MPa∙m1/2 to 7.0 MPa∙m1/2 for the acid-treated SA/C fibre addition.

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Mechanical and Optical Properties of Polylactic Acid Films Containing Surfactant-Modified Cellulose Nanocrystals

Journal of Nanomaterials ◽

10.1155/2018/7124260 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Jose Luis Orellana ◽

Derek Wichhart ◽

Christopher L. Kitchens

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Optical Properties ◽

Polylactic Acid ◽

Cellulose Nanocrystals ◽

Cetyltrimethylammonium Bromide ◽

Polymeric Matrices ◽

Nanoscale Structure ◽

Surface Modified ◽

Modified Cellulose

The addition of surface-modified cellulose nanocrystals (CNCs) to polymeric matrices can lead to an enhancement of the mechanical and optical properties of host polymers. The use of surfactants can provide an easy and effective way to change the CNC functionality and to evaluate the effects of surface chemistry in the reinforcement mechanisms. In this work, CNCs were solution blended with polylactic acid (PLA) and melt extruded into films. The PLA toughness increased from 1.70 MJ/m3to 2.74 MJ/m3, a 61% increase, with the addition of 1% of decylamine-modified CNCs without a decrease of the tensile strength or modulus. In this work, we investigated the use of two surfactants, decylamine and cetyltrimethylammonium bromide, to enhance CNC compatibility with the hydrophobic PLA matrix. Decylamine at 1.0 wt.% with respect to CNC loading was found to significantly enhance CNC compatibility and property enhancement. The low concentration of surfactant is notable, as other works typically use significantly higher loadings for CNC incorporation and property enhancement. At high CNC concentrations, mechanical properties decreased but the aligned assembly of the CNCs provided intricate colors to the films when observed between crossed polars. The alignment and nanoscale structure of CNCs within the films play an important role in the properties obtained.

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