5.2.5 Silane treatment
Silanes are one of the widely used coupling agent in glass fiber filled, mineral filled and natural fiber filled polymer composites [8], [9], [24], [62]. Silane molecules have bifunctionl groups that may respectively react with the two phases there by forming bridge and increase the interfacial adhesion in between them. Silanes used in natural fiber composites are generally trialkoxy silanes having general structure R- (CH2)n – Si- (OR1)3, Where n = 0 to3, R1 is the hydrolyzable alkoxy group generally methoxy and ethoxy, and R the functional organic group. The functional group R of the silane interacts with the polymer matrices and the mode of interaction depends on reactivity or compatibility of the functional group towards the polymer. A non- reactive alkyl group of the silane may increase the compatibility with non-polar matrix due to their similar polarities; whereas the reactive functional
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Two organic peroxides namely, benzoyl peroxide (BP) and dicumyl peroxide (DCP) are commonly used to for fiber modification. Solution of the peroxide in acetone is commonly employed for coating of fiber after alkaline pretreatment. The organic peroxide easily decomposed to produce free radical (RO•). Thus formed free radical react with hydrogen of the polymer matrix and wood polymer and hence the fiber is covalently bonded with polymer. The reaction scheme is given below [8], [9].
Fig: Peroxide treatment
Similarly, the potassium permanganate treatment of the fiber is carried out by dipping the fiber in potassium permanganate solution for few minutes in acetone after alkaline pre-treatment. This treatment leads to formation of reactive cellulose radical (as shown in scheme) that enhance the chemical interlocking at the interface
The papermaking process begins with pulp. Pulp is cellulosic fibrous material extracted from cellulosic fiber from wood. Glatfelter uses the Kraft Process to make both hardwood and softwood pulps. Hardwood pulps are taken from oaks, beeches, poplars, birches and eucalyptus tress. They have short fibre of average length of 1 millimeter. The primary purpose of hardwoods is for the paper to achieve bulkiness, smoothness and opacity. Softwood on the other hand is taken from pine and spruce with long fibre averaging 3 millimeters, it provides addition strength to paper. Both softwood and hardwood are produce independently of each other and are mixed end at desire ratio in the paper plant. The process starts from wood chips. Trees are chipped to make wood chips from half an inch to an inch long and up to two fifth inches thick. The chips are feed into a digester, which with cooking liquor would create a chemical reaction, which delignificate the wood. The cooking liquor is composed of white and black liquor. White liquor is composed of mainly sodium hy...
Chemically all polymeric materials comprise of hydro-carbon chains and usually have high heat of combustion. When they are exposed to fire, they burn rapidly with the release of high amount of heat, flame and smoke. Similarly the natural fibers, wood flour, are highly combustible and burn rapidly. So for safely use of the composites materials they must have flame retardant properties as well.
The Crystallinity of Kevlar Polymer strands, contributes to the unique strength and stiffness of the material. Kevlar is very similar to other common synthetic polymers, including Nylon, Teflon and Lycra. In all Polated to strength. Aromatic refers to the Carbon atoms attached in a ring, and Amides refers to a group of Carbon, Nitrogen and Hydrogen atoms. Kevlar fiber is therefore a “Polyaromatic amide”, as it has a high breaking strength.
The benefits of silica are generally targeted towards women. It is marketed as the perfect beauty supplement for hair, skin, and nails.
If the part or piece still has its structural strength then an epoxy product could be used. Some of these epoxies that are used bondo and POR 15. When using these pro...
In this experiment the purpose was to synthesize a synthetic dye, methyl orange, and test its effectiveness by performing a dye test with fabric. Methyl orange is an azo dye made from a synthesis reaction between sulfanilic acid and N,N-dimethylaniline. The preparation for this synthesis involves two steps: diazotization and coupling reaction. The diazotization step is the first step where the sulfanilic acid sodium salt reacts with the sodium nitrite in HCl to form an unstable diazonium salt. The coupling reaction is the second step where the diazonium ion is used in the reaction mixture and reacts with N,N-dimethylaniline to form an acidic azo dye.
In order to gain strong insight into the surface chemistry of silica we have perform a thorough literature search. Our goal is to identify the pioneer research performed on silica and silica supported catalyst. Particular interest lies in silica-water-cobalt and silica-alcohol-cobalt systems. This study is both on macro and micro level so that a complete theoretical base can be established. From this theoretical knowledge, key areas to look upon will be identified and a design of experiments will be established. The goal is to develop a both efficient and effective product (catalyst) using a novel methodology developed from past research.
however, is a synthetic fiber. It is a polyamide whose molecular chains are formed by regularly
In this experiment we produced a Nylon-6,10 polymer from a reaction with a sebacoyl chloride (decanedioyl dichloride)/dichloromethane mixture and a mixture of water, 1,6-hexanediamine and sodium carbonate. The name ‘Nylon-6,10’ indicates that the diamine that it was made from has 6 carbons and the diacid it was made from has 10 carbons. The sodium carbonate was used in the preparation of Nylon-6,10 because it is a strong base that will lower the acidity of the solution and neutralize the hydrochloric acid that was produced as a by-product. The HCl was produced as a by-product instead of water because we used milder conditions by substituting decanedioyl dichloride for decanedioic acid. The decanedioyl dichloride is a better alternative because it is more reactive towards the
There are two popular ways of creating nylon for fiber applications. One, ¡°molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH©ü) groups on each end.¡± The nylon 6,6 is made in this fashion. The other common way of making nylon fibers is by polymerizing a compound containing an amine at one end and an acid at the other, to form a chain with reoccurring groups of (-NH-[CH©ü]n-CO-)x. If the x=5, the fiber is named nylon 6 (Nylon Fiber).
BACKGROUND Types of Silica Crystalline silica may be of several distinct types. Quartz, a form of silica and the most common mineral in the earth's crust, is associated with many types of rock. Other types of silica include cristobalite and tridymite. Potential for Exposure During Construction Concrete and masonry products contain silica, sand and rock containing silica. Since these products are primary materials for construction, construction workers may be easily exposed to respirable crystalline silica during activities such as the following: Chipping, hammering, and drilling of rock Crushing, loading, hauling, and dumping of rock   high dust concentrations.
chains instead of hydrogen atoms. Cross-linking is another way in which the polymer can be made stronger. This involves ultraviolet radiation that bombards the polymer with electrons and formulates bonds between the molecular chains of the polymers. This is like linear polyethylene but different in that it is more impact resistant, and it has a much higher density. This allows it to be stored or be used with different chemicals that would normally cause the polymer to desolve.3 This can start to become a problem because as the polymer continues to become chemically enhanced. So the ways of dissolving and recycling the polymer become more difficult.
Rubber on exposure to air or sun light produces cracks, and if any tensile stress is applied the cracks appears clearly. To avoid these cracks so far it has been known to use the antioxidants from amines and those from wax. Usually amines are subjected to a chemical reaction selectively with ozone and consumes the ozone in the surface layer of rubber to prevent the rubber from aging under statical or dynamical conditions, whereas wax incorporated in a rubber exudes to the surface to form a thin film, which prevents the rubber from contacting with ozone to produce an antioxidizing effect, particularly under statical conditions. Moreover, generally the above two kinds of agents are used together at the same time. The antioxidant wax for rubber relates to the latter, namely, the statical antioxidant [27].
The preparation of making wood into a pulp for papermaking is accomplished in two different ways. In the groundwood process, blocks of wood are held against a fast revolving grindstone that shreds off short wood fibbers from the block. The fibbers produced by this process are short and are used only in the production of cheap newsprint and used to be added with other types of wood fibber in the making of high-quality paper. Another technique uses a chemical-solvent processes where wood chips are treated with solvents that remove “resinous material and lignin” from the wood, leaving pure fibbers of cellulose.
present at all times but it must retain some of them. All plant life on Earth benefits from the ability of water to make a hydrogen bond with another substance of similar electronegative charge. Cellulose, the substance that makes up cell walls and paper products, is a hydrophilic substance ("water-loving"). It interacts with water but, unlike other hydrophilic substances, it will not dissolve in it. Cellulose can form strong hydrogen bonds with water molecules. This explains why a paper towel will "wick" water upwards when it comes in contact with it.