Effects of processing conditions on properties of nano-SiO2/polypropylene composites fabricated by pre-drawing technique

2007 ◽  
Vol 67 (13) ◽  
pp. 2747-2756 ◽  
Author(s):  
Wen Hong Ruan ◽  
Yu Liang Mai ◽  
Xian Hou Wang ◽  
Min Zhi Rong ◽  
Ming Qiu Zhang
2011 ◽  
Vol 33 (1) ◽  
pp. 183-187 ◽  
Author(s):  
Amir Nourbakhsh ◽  
Foad Farhani Baghlani ◽  
Alireza Ashori

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shadi Houshyar ◽  
Robert A. Shanks

AbstractPreparation and characterization of novel composites, consisting of polypropylene (PP) fibres in a random poly(propylene-co-ethylene) (PPE) matrix, were investigated. These composites possess unique properties, due to chemical compatibility of the two polymers allowing creation of strong physico-chemical interactions and strong interfacial bonds. The difference between the melting temperatures of PP fibre and PPE was exploited in order to establish processing conditions for the composites. Suitable conditions were chosen so that the matrix was a liquid, to ensure good wetting and impregnation of the fibres, though the temperature must not be high enough to melt the fibres. The morphology of the composites was investigated using optical and scanning electron microscopy. Optical microscope images showed that transcrystallization of the matrix was observed on PP fibre surfaces. SEM photographs displayed a thin layer of matrix on the reinforcement, attributed to good impregnation and wetting of the fibres. Adhesion between PPE matrix and PP fibres was characterized using a microbond test inspired by a fibre pull-out technique. The results showed that adhesion was appreciably increased when PP fibres were used instead of glass fibres in the matrix. Nevertheless, thermal processing conditions of the composites caused reduction in mechanical behaviour of the reinforcement.


2009 ◽  
Vol 69 (2) ◽  
pp. 252-259 ◽  
Author(s):  
J CHEN ◽  
M RONG ◽  
W RUAN ◽  
M ZHANG

2011 ◽  
Vol 332-334 ◽  
pp. 1659-1665
Author(s):  
Song Mei Bi ◽  
Jun Hong ◽  
Chang Liu Chu

The effect of molding temperature, pressure, packing time and cooling methods on the properties of ramie roving reinforced polypropylene composites was mainly investigated in this paper. We used moulding process to prepare the ramie fiber/PP (Polypropylene) composites with the ramie roving as the reinforcement which were loosed into a single fiber state in the case of without affecting the fiber’s longitudinal straightness, and then investigated the influence of processing conditions to the mechanical properties of composites. With the DSC (Differential Scanning Calorimetry), the effect of cooling conditions on the crystallization of composites was also discussed. The result shows that taking ramie roving as the reinforcement will improve the infiltration properties of the PP matrix to ramie fibers, the reason is that ramie fibers have good orientation and it is loosely arranged in the ramie roving , all of these are benefit to form a good interfacial bonding between fibre and PP resin. Different processing conditions have great impact on the mechanical properties of composites. And the samples gained the best merchanical properties when the process conditions such as molding temperature, pressure, packing time are selected as 165°C, 8MPa, 10min. When the composites cooled together with the heating plate, its melting enthalpy is the highest and the crystallization properties is better than other cooling methods such as home temperature cooling and quickly water-cooling, and its tensile properties is the best.


2003 ◽  
Vol 11 (7) ◽  
pp. 559-562 ◽  
Author(s):  
Chun Lei Wu ◽  
Ming Qiu Zhang ◽  
Min Zhi Rong ◽  
Björn Lehmann ◽  
Klaus Friedrich

2001 ◽  
Vol 10 (6) ◽  
pp. 096369350101000 ◽  
Author(s):  
N. E. Zafeiropoulos ◽  
C. A. Baillie ◽  
F. L. Matthews

In recent years there has been an increasing interest in using natural fibres as potential reinforcements for polymers. It is well known that the properties of composite materials are controlled by the properties of the matrix and the fibre, as well as of the interface. The most usual methods of strengthening the interface involve the application of surface modification methods on the fibres, or the application of compatibilisers in the matrix. However, it may be possible that one may achieve similar results just by simply controlling the processing conditions, and thus avoiding the application of chemicals that tend to increase the cost. In the present study the effect of cooling rates upon the interface in flax fibre/iPP composites was investigated by means of fragmentation tests. It was found that slower cooling leads to a stronger interface for two different grades of flax fibres; dew retted and green flax.


2017 ◽  
Vol 51 (24) ◽  
pp. 3365-3372 ◽  
Author(s):  
Marisa Cristina Guimarães Rocha ◽  
Gisele Fonseca Moreira ◽  
Antonio Henrique Monteiro Fonseca Thomé da Silva

Processing variables are known to have a decisive influence on the impact properties of polypopylene-nano-CaCO3 composites. Therefore, it becomes mandatory to evaluate the effect of extrusion conditions on composite impact resistance. In the present work, a response surface methodology was used to evaluate the effects of screw rotation speed, screw configuration, and nanoparticles content on the polypropylene impact properties. The concentration of the nano-CaCO3 particles, the screw rotation speed, and the interaction between these entrance factors were the processing variables of greater influence on the impact properties of nano-CaCO3/polypropylene composites. The increase of screw rotation speed led to a decrease in the impact resistance, while the increase of filler content promoted an increase of such property. However, the increase of nanoparticles content led to obtaining poor tensile properties. Therefore, the filler content has to be adjusted in order to improve the impact properties without significant loss of mechanical strength.


Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.


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