Interfacial properties of all-polypropylene composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shadi Houshyar ◽  
Robert A. Shanks
Keyword(s):  
Optical Microscope ◽  
Processing Conditions ◽  
Polypropylene Composites ◽  
Melting Temperatures ◽  
Pull Out ◽  
Physico Chemical ◽  
Microbond Test ◽  
The Matrix ◽  
The Difference ◽  
Poly Propylene

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.

Investigation of Meniscus Effect on Microbond Test of Typha Fiber/Epoxy Matrix

2020 ◽  
Vol 402 ◽  
pp. 14-19
Author(s):  
Andri Afrizal ◽  
Ikramullah ◽  
Syarizal Fonna ◽  
Syifaul Huzni
Keyword(s):  
Epoxy Matrix ◽  
Maximum Stress ◽  
Interfacial Shear Strength ◽  
Von Mises Stress ◽  
Microbond Test ◽  
The Matrix ◽  
The Difference ◽  
Von Mises ◽  
The Impact ◽  
Fiber Radius

The microbond test was one of the methods to examine the interfacial shear strength (IFSS) value of fiber and polymer matrix. The meniscus angle that formed at both ends of the matrix is difficult to control while manufacturing the specimen for the microbond test. Therefore, the effect of meniscus angle must be evaluated. In this paper, we evaluated the impact of variations of the meniscus angle against the maximum von-mises stress and the IFSS value of the Typha fiber epoxy matrix by finite element method. The geometry of the microbond test specimen was modeled with 0.25 mm fiber radius, 2 mm fiber length, 1.75 mm embedded length of the matrix, and varied the meniscus angles with 22°, 30°, 45°, 60°, 75°, and 90°. The mesh type quad-dominated CAX4R is used on fiber and matrix, while quad COHAX4 is applied to the cohesive element between fiber and matrix. The constantly applied displacement was adjusted to the upper end of the fiber at 0.6 mm. The simulation results showed that the difference in maximum stress obtained in each model. Furthermore, that is not given much difference in IFSS value. It can be concluded that the meniscus angle affects the maximum von-mises stress but not too much-affected IFSS value of the fiber and epoxy matrix.

scholarly journals An Investigation of the Effect of Processing Conditions on the Interface of Flax/Polypropylene Composites

2001 ◽  
Vol 10 (6) ◽  
pp. 096369350101000 ◽  
Author(s):  
N. E. Zafeiropoulos ◽  
C. A. Baillie ◽  
F. L. Matthews
Keyword(s):  
Surface Modification ◽  
Composite Materials ◽  
Flax Fibre ◽  
Natural Fibres ◽  
Processing Conditions ◽  
Cooling Rates ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
The Matrix ◽  
The Cost

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.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Development of Prolonged Delivery of Tramadol and Dissolution Translation by Statistical Data Treatment

2011 ◽  
Vol 4 (1) ◽  
pp. 1331-1337
Author(s):  
P B Parejiya ◽  
B S Barot ◽  
P K Shelat
Keyword(s):  
Drug Release ◽  
Study Data ◽  
Stability Study ◽  
Dissolution Time ◽  
Matrix Tablet ◽  
Burst Effect ◽  
The Matrix ◽  
The Mean ◽  
The Difference ◽  
Dissolution Efficiency

The present study was carried out to fabricate a prolonged design for tramadol using Kollidon SR (Polyvinyl acetate and povidone based matrix retarding polymer). Matrix tablet formulations were prepared by direct compression of Kollidon SR of a varying proportion with a fixed percentage of tramadol. Tablets containing a 1:0.5 (Drug: Kollidon SR) ratio exhibited a rapid rate of drug release with an initial burst effect. Incorporation of more Kollidon SR in the matrix tablet extended the release of drug with subsequent minimization of the burst effect as confirmed by the mean dissolution time, dissolution efficiency and f2 value. Among the formulation batches, a direct relationship was obtained between release rate and the percentage of Kollidon SR used. The formulation showed close resemblance to the commercial product Contramal and compliance with USP specification. The results were explored and explained by the difference of micromeritic characteristics of the polymers and blend of drug with excipients. Insignificant effects of various factors, e.g. pH of dissolution media, ionic strength, speed of paddle were found on the drug release from Kollidon-SR matrix. The formulation followed the Higuchi kinetic model of drug release. Stability study data indicated stable character of Batch T6 after short-term stability study.

scholarly journals Study on the Dissolution and Precipitation Behavior of Self-Designed (NbTi)C Nanoparticles Addition in 1045 Steel

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 184
Author(s):  
Hongwei Zhu ◽  
Haonan Li ◽  
Furen Xiao ◽  
Zhixiang Gao
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Cast Steels ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Thermo Calc Software ◽  
Particle Strengthening ◽  
1045 Steel ◽  
Addition Amount

Self-designed (NbTi)C nanoparticles were obtained by mechanical alloying, predispersed in Fe powder, and then added to 1045 steel to obtain modified cast steels. The microstructure of cast steels was investigated by an optical microscope, scanning electron microscope, X-ray diffraction, and a transmission electron microscope. The results showed that (NbTi)C particles can be added to steels and occur in the following forms: original ellipsoidal morphology nanoparticles with uniform dispersion in the matrix, cuboidal nanoparticles in the grain, and microparticles in the grain boundary. Calculations by Thermo-Calc software and solubility formula show that cuboidal (NbTi)C nanoparticles were precipitated in the grain, while the (NbTi)C microparticles were formed by eutectic transformation. The results of the tensile strength of steels show that the strength of modified steels increased and then declined with the increase in the addition amount. When the addition amount was 0.16 wt.%, the modified steel obtained the maximum tensile strength of 759.0 MPa, which is an increase of 52% compared with to that with no addition. The hardness of the modified steel increased with the addition of (NbTi)C nanoparticles. The performance increase was mainly related to grain refinement and the particle strengthening of (NbTi)C nanoparticles, and the performance degradation was related to the increase in eutectic (NbTi)C.

scholarly journals Microencapsulation of Flaxseed Oil—State of Art

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 295
Author(s):  
Asma Yakdhane ◽  
Sabrine Labidi ◽  
Donia Chaabane ◽  
Anita Tolnay ◽  
Arijit Nath ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gum Arabic ◽  
Tween 80 ◽  
Flaxseed Oil ◽  
Review Article ◽  
Wall Material ◽  
Physico Chemical ◽  
Comprehensive Information ◽  
The Matrix

Microencapsulation is a well-known technology for the lipid delivery system. It prevents the oxidation of fatty acids and maintains the quality of lipid after extraction from oil seed and processing. In flaxseed oil, the amount of ω-3 and ω-6 polyunsaturated fatty acids are 39.90–60.42% and 12.25–17.44%, respectively. A comprehensive review article on the microencapsulation of flaxseed oil has not been published yet. Realizing the great advantages of flaxseed oil, information about different technologies related to the microencapsulation of flaxseed oil and their characteristics are discussed in a comprehensive way, in this review article. To prepare the microcapsule of flaxseed oil, an emulsion of oil-water is performed along with a wall material (matrix), followed by drying with a spray-dryer or freeze-dryer. Different matrices, such as plant and animal-based proteins, maltodextrin, gum Arabic, and modified starch are used for the encapsulation of flaxseed oil. In some cases, emulsifiers, such as Tween 80 and soya lecithin are used to prepare flaxseed oil microcapsules. Physico-chemical and bio-chemical characteristics of flaxseed oil microcapsules depend on process parameters, ratio of oil and matrix, and characteristics of the matrix. As an example, the size of the microcapsule, prepared with spray-drying and freeze-drying ranges between 10–400 and 20–5000 μm, respectively. It may be considered that the comprehensive information on the encapsulation of flaxseed oil will boost the development of functional foods and biopharmaceuticals.

scholarly journals Effect of natural disinfectant (Moringa oleifera) and a chemical disinfectant (calcium hypochlorite) on nematode eggs: bioefficiency and impact of physico-chemical variables

2020 ◽  
Vol 10 (2) ◽  
pp. 335-346
Author(s):  
Arnold Landry Fotseu Kouam ◽  
Gideon Aghaindum Ajeagah
Keyword(s):  
Petri Dish ◽  
Nematode Species ◽  
Optical Microscope ◽  
Chemical Parameters ◽  
Calcium Hypochlorite ◽  
Physico Chemical ◽  
Before And After ◽  
Nematode Eggs ◽  
Chemical Disinfectant ◽  
Physical And Chemical

Abstract The aim of this study is to determine the effectiveness of disinfectant on the viability of eggs from three nematode species (Ascaris, Trichuris, Ankylostoma). It was conducted in a microcosm from June 2018 to June 2019. The wastewater scan was sampled using 5 L sterile containers, the sample was arranged in four replicas, three tests and one control. The test samples received three disinfectants (Moringa, calcium hypochlorite and Moringa associated with calcium hypochlorite) at varying concentrations. The physical and chemical parameters were measured before and after the application of each disinfectant. The samples were then observed under an optical microscope. The viability of the eggs was determined by incubating the Petri dish samples at 30 °C for 30 days. The analyses show that some physicochemical parameters can significantly influence the efficacy of disinfectant on the eggs. The calcium hypochlorite associated with Moringa at 0.6 g/L showed greater efficacy on reducing viability and inactivation of eggs with 100% efficacy yield rates on Ankylostoma and Trichuris trichiuria and 97% on Ascaris lumbricoides eggs; this efficacy is significantly different from that observed on samples treated with Moringa and simple calcium hypochlorite. Of the three parasites tested, A. lumbricoides showed greater resistance to the disinfectant.

scholarly journals Accelerated aging of WPCs Based on Polypropylene and Birch plywood Sanding Dust

2021 ◽  
Vol 11 (1) ◽  
pp. 319-328
Author(s):  
Janis Kajaks ◽  
Karlis Kalnins ◽  
Juris Matvejs
Keyword(s):  
Accelerated Aging ◽  
Degree Of Crystallinity ◽  
Accelerated Weathering ◽  
Recrystallization Process ◽  
Surface Layers ◽  
Uv Aging ◽  
Polypropylene Composites ◽  
Weathering Processes ◽  
Melting Temperatures ◽  
Dsc Measurements

Abstract A lot of researchers are closely related with natural, lignocellulose fibre containing bio-composites production and studies. Various of polymer matrices, mainly polyolefins, combinations with natural fibres as a reinforcement are used. Our studies are focused on polypropylene based bio-composites containing birch plywood production by-product sanding dust (PSD) accelerated weathering processes. The obtained results showed the following sight. After the aging the surface of all samples had faded, the changes of the gloss (decreasing) and of the whiteness degree (increasing) also had taken place, but microhardness of the surface of specimens significantly has decreased. The tensile strength and modulus of the samples after UV aging diminished about 30–35%. That indicates to the changes not only in the surface layers of polymer but also inside of the polymer structure. The FTIR measurements showed that during UV aging process occurs significant changes of chemical structure of the weathered surface of all samples. DSC measurements showed an increase of degree of crystallinity of the weathered polypropylene composites after the first heating due to the recrystallization process in the polypropylene matrix and a small decreasing after second heating. The melting temperatures of all composites after UV aging considerably diminish up to 30°C.

Effect of Sisal Fiber Surface Treatments on Sisal Fiber Reinforced Polypropylene (PP) Composites

2014 ◽  
Vol 906 ◽  
pp. 167-177 ◽  
Author(s):  
Hou Lei Gan ◽  
Lei Tian ◽  
Chang Hai Yi
Keyword(s):  
Surface Morphology ◽  
Morphological Changes ◽  
Fiber Surface ◽  
Atmospheric Plasma ◽  
Single Fiber ◽  
Sisal Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Pull Out ◽  
Debonding Process

Abstract: The Interface of sisal fiber which was treated by using alkali, potassium permanganate, atmospheric plasma and silane reinforced polypropylene composites were investigated by single fiber pull-out testes and surface morphology were studied. The results indicated that the morphological changes observed on the sisal fiber surface were obviously evident. Untreated, permanganate and plasma treated sisal fiber reinforced PP show a stable debonding process. Silane treated sisal fiber reinforced PP show an unstable debonding process. Single fiber pull-out tests indicated that the IFSS value was in the order of FIB < FIBKMnO4 < FIBP < FIBKH-550 < FIBKH-570. As can be seen from surface morphology of pull-out fiber, a little of PP resin was adhered to the pull-out FIB, FIBKMnO4, FIBP of sisal fiber. In contrast, PP resin at the surface of pull-out fiber was flaked off and sisal fibril was drawn out from sisal fiber were observed from pull-out fibers of FIBKH-550 and FIBKH-570.

Physico-chemical Characterization of Forest and Agricultural Residues for Energy Conversion Processes

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Nguyen Hong Nam ◽  
Le Gia Thanh Truc ◽  
Khuong Duy Anh ◽  
Laurent Van De Steene
Keyword(s):  
Energy Conversion ◽  
Chemical Characterization ◽  
Calorific Value ◽  
Forest Residues ◽  
Physico Chemical ◽  
Wide Range ◽  
Biomass Resources ◽  
Thermochemical Processes ◽  
The Difference

Agricultural and forest residues are potential sources of renewable energy in various countries. However, the difference in characteristics of biomass resources presents challenges for energy conversion processes which often require feedstocks that are physically and chemically consistent. This study presented a complete and comprehensive database of characteristics of a wide range of agricultural and forest residues. Moisture, bulk density, calorific value, proximate and elemental compositions, as well as cellulose, hemicellulose, and lignin compositions of a wide range of biomass residues were analyzed. The major impacts of the variability in biomass compositions to biochemical and thermochemical processes were also discussed.

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