Polypropylene-Based Biocomposites Reinforced by Tailor-Modified Cellulose Fibers and Microfibrils

2013 ◽  
Vol 671-674 ◽  
pp. 1826-1829
Author(s):  
Yuan Feng Pan ◽  
Shu Zhao Li ◽  
Hui Ning Xiao
Keyword(s):  
Cellulose Fibers ◽  
Optimal Dosage ◽  
Reinforced Composites ◽  
Cellulose Fibres ◽  
Natural Cellulose ◽  
Cellulose Fibrils ◽  
Core Shell Structure ◽  
Cationic Latex ◽  
Modified Cellulose

Two approaches of improving the toughness of polypropylene (PP)-based composites reinforced by natural cellulose fibers were developed. The surface modification of cellulose fibrils (CMF) or fiber by either in-situ grafting polymerization of butyl acrylate (BA) on CMF surface via an atom transfer radical polymerization (ATRP) or adsorbing the cationic polymeric latex with core-shell structure on fiber surfaces was performed; and resulting fibers or CMF were used as reinforments in an attempt to enhance the toughness of the PP-based composites. The results of mechanical properties indicated that the flexure, tensile, and impact strengths of the CMF-g-PBA reinforced composites were all improved. The cellulose fibres treated by cationic latex also showed the same trend. The optimal dosage of latex for hydrophobic-modifying fibers was also identified.

scholarly journals In Situ Synthesis of Core-Shell-Structured SiCp Reinforcements in Aluminium Matrix Composites by Powder Metallurgy

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1201
Author(s):  
Xinghua Ji ◽  
Cheng Zhang ◽  
Shufeng Li
Keyword(s):  
Particle Size ◽  
Powder Metallurgy ◽  
Shell Structure ◽  
Ex Situ ◽  
Aluminium Matrix ◽  
Core Shell ◽  
Matrix Composites ◽  
Aluminium Matrix Composites ◽  
Core Shell Structure

SiCp reinforced aluminium matrix composites (AMCs), which are widely used in the aerospace, automotive, and electronic packaging fields along with others, are usually prepared by ex situ techniques. However, interfacial contamination and poor wettability of the ex situ techniques make further improvement in their comprehensive performance difficult. In this paper, SiCp reinforced AMCs with theoretical volume fractions of 15, 20, and 30% are prepared by powder metallurgy and in situ reaction via an Al-Si-C system. Moreover, a combined method of external addition and an in situ method is used to investigate the synergistic effect of ex situ and in situ SiCp on AMCs. SiC particles can be formed by an indirect reaction: 4Al + 3C → Al4C3 and Al4C3 + 3Si → 3SiC + 4Al. This reaction is mainly through the diffusion of Si, in which Si diffuses around Al4C3 and then reacts with Al4C3 to form SiCp. The in situ SiC particles have a smooth boundary, and the particle size is approximately 1–3 μm. A core-shell structure having good bonding with an aluminium matrix was generated, which consists of an ex situ SiC core and an in situ SiC shell with a thickness of 1–5 μm. The yield strength and ultimate tensile strength of in situ SiCp reinforced AMCs can be significantly increased with a constant ductility by adding 5% ex situ SiCp for Al-28Si-7C. The graphite particle size has a significant effect on the properties of the alloy. A criterion to determine whether Al4C3 is a complete reaction is achieved, and the forming mechanism of the core-shell structure is analysed.

Manufacture and Microstructures of Fe-Cr-C Hypereutectic In Situ Composites

2007 ◽  
Vol 336-338 ◽  
pp. 1406-1408 ◽  
Author(s):  
Xiao Hui Zhi ◽  
Jian Dong Xing ◽  
Yi Min Gao ◽  
Xiao Jun Wu ◽  
Xiao Le Cheng
Keyword(s):  
Hypereutectic Alloy ◽  
Reinforced Composites ◽  
In Situ Composites ◽  
In Situ Composite ◽  
Particle Reinforced Composites ◽  
Primary Carbides

In the present study, a Fe-Cr-C hypereutectic alloy was prepared from industry-grade materials and subjected to modification and fluctuation, through which new types of particle reinforced composites, hypereutectic in-situ composite, was generated. The structures of the composite modified or not with the range of fluctuation addition from 0% to 2.8wt.%, were investigated. The primary carbides were refined with the addition of modifying agents and fluctuations. Increasing the amount of fluctuation resulted in finer primary carbides. At 1380oC, with the addition of modifying agents and 2.8wt.% fluctuation addition, the structure was well modified.

Effect of Surface Grafting-Modified on Structure and Property of Cellulose Fibers

2012 ◽  
Vol 627 ◽  
pp. 43-48
Author(s):  
Shu Hua Wang ◽  
Jin Ming Dai ◽  
Hu Sheng Jia ◽  
Bing She Xu
Keyword(s):  
Cellulose Fibers ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Wet Strength ◽  
Structure And Property ◽  
Chemically Modified ◽  
Crosslinking Process ◽  
Acrylamide Polymerization ◽  
Modified Cellulose ◽  
Effect Of Surface

Cellulose fibers were chemically modified on surface by acrylamide polymerization and glutaraldehyde crosslinking. The chemical and morphological structures of modified cellulose fibers were investigated with X-ray diffraction, FTIR spectra, and scanning electron microscopy (SEM). The crystalline conformations of the cellulose fibers were slightly changed in polymerization and crosslinking process. The wet strength of modified cellulose fibers was improved. Appreciable difference between the surfaces of native and modified cellulose fibers was observed from SEM images.

Sign in / Sign up

Export Citation Format

Share Document