Comprehensive characterization sea purslane (Sesuvium portulacastrum) fiber and the effect of surface modifications on physical, mechanical and thermal properties

2021 ◽  
pp. 1-13
Author(s):  
Janaki Dehury ◽  
Subhakanta Nayak ◽  
Jyoti Ranjan Mohanty
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
David Cisneros-Rosado ◽  
Jorge Alonso Uribe-Calderon

The effect of surface modification of palygorskite (Pal) on filler dispersion and on the mechanical and thermal properties of polypropylene (PP)/polypropylene grafted maleic anhydride (PP-g-MAH)/palygorskite (Pal) nanocomposites was evaluated. A natural Pal mineral was purified and individually surface modified with hexadecyl tributyl phosphonium bromide and (3-Aminopropyl)trimethoxysilane; the pristine and modified Pals were melt-compounded with PP to produce nanocomposites using PP-g-MAH as compatibilizer. The grafting of Pal surface was verified by FT-IR and the change in surface hydrophilicity was estimated by the contact angle of sessile drops of ethylene glycol on Pal tablets. The extent of Pal dispersion and the degree of improvement in both the mechanical and thermal properties were related to the surface treatment of Pal. Modified Pals were better dispersed during melt processing and improved Young’s modulus and strength; however, maximum deformation tended to decrease. The thermal stability of PP/PP-g-MAH/Pal nanocomposites was considerably improved with the content of modified Pals. The degree of crystallinity increased with Pal content, regardless of the surface modification. Surfactant modified Pal exhibited better results in comparison with silane Pal; it is possible that longer alkyl chains from surfactant molecules promoted interactions with polymer chains, thereby improving nanofiller dispersion and enhancing the properties.


2020 ◽  
Vol 847 ◽  
pp. 108-113
Author(s):  
Yeng Fong Shih ◽  
Venkata Krishna Kotharangannagari ◽  
You Ting Lin

In this study, a series of nanocomposites were prepared by melt-blending method using Nylon (Nylon12, PA12) and multi-walled carbon nanotubes (MWCNTs) with various contents such as 0.0 wt.%, 0.5 wt.%, 1.0 wt.%, 3.0 wt.%. In order to improve the dispersion of MWCNTs in composites, the MWCNTs were first acid treated by the HNO3 solution to functionalize the carboxylic groups on the surface. Subsequently, this acid treated MWCNTs were reacted with Polyetheramine (Jeffamine® M2070) and Polyethylenimine under mild conditions, respectively, to obtain the chemically modified MWCNTs (M-M2070 and M-PEI). The amide groups formed on these chemically modified MWCNTs will enhance the compatibility of MWCNTs and Nylon. The effects of different modification methods on the thermal properties, mechanical properties and electrical resistance of these Nylon12/MWCNTs composites were investigated. The results showed that M-M2070 and M-PEI dispersed in Nylon12 homogeneously, and can improve the mechanical and thermal properties of the composite materials effectively. The DMA analysis revealed that the storage moduli of nanocomposites were increased with increasing MWCNTs content. Among all, the nanocomposites containing 3wt% of M-M2070 and M-PEI were shown increased storage moduli 48.2% and 29.8%, respectively. TGA analysis showed that pyrolysis temperature of neat Nylon12 was 412.7 °C, and was increased about 43 °C by addition of M-M2070 and 36.7 °C by addition of M-PEI. Moreover, the surface resistance of neat Nylon12 was 1.68×1014 ohm/sq, and was decreased to 1.33×105 and 4.34×106 ohm/sq by addition of 3wt% M-M2070 and M-PEI, respectively. The resistance values of these nanocomposites have achieved the level of static dissipation, and can prevent the harm of static electricity.


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