Bonding agent EBA consist of:
OR
What does Enamel bonding agent (EBA) consist of:
- a- Unfilled resin ***
- B- primer and bonding agent
- c- A mixture of resins in an acetone or ethanol solvent
- d- A wetting agent and resins
- e- A mixture of priming and bonding agents.
Ethanol:
It is the most important commercial alcohol, it is used as a disinfectant, in addition to being present in alcoholic beverages. The alcohol present in alcoholic beverages is produced by the fermentation process, but to obtain a higher concentration of ethanol in the drinks, distillation is used. Ethanol is not as toxic as methanol, but if large amounts are consumed in a short time, it can cause death.The indiscriminate consumption of ethanol (alcoholism) is one of the biggest health problems in the world today. Surprisingly it has been found that the approximate ingestion of 1 or 2 glasses of red wine per day is related to the decrease in heart attacks.
Industrially, ethanol is used to make other organic compounds, medication solvent, lotion solvent and friction products, as well as being used as an additive in gasoline.
Acetone:
Acetone is a commercially important ketone, as it is an excellent solvent, since it dissolves many organic compounds and, in addition, is miscible with water. It is used in nail polish removers and in the manufacture of dyes. It is a colorless liquid with an easy to distinguish smell and taste. It evaporates easily, is flammable and is infinitely miscible with water.Acetone is used in the manufacture of plastics, fibers, medications and other chemicals. It is also used to dissolve other chemicals.
Saccharin:
Saccharin is the oldest artificial sweetener since it was discovered in 1879, but although it has many properties or advantages it also creates controversy. Saccharin is a sweetener 300 times sweeter than sugar although, since it has a slightly bitter aftertaste, it is usually associated with other artificial sweeteners. It can be presented in the form of pills, granules, powder or liquid. It is very stable and has a long duration. It is eliminated in the urine. We can find it as an ingredient in products as diverse as: juices, ice cream, soft drinks, jams, dairy products, toothpaste, buns, cookies, chewing gum, some medicines, etc.Ethylene glycol:
Ethylene glycol is the main component of the antifreeze solutions used in car radiators. This substance raises the boiling point and decreases the freezing of water, that is, it prevents the formation of ice in winter and decreases vaporization in the summer.FUNCTIONAL GROUPS:
A molecule of a carbon compound (organic compound) consists of a hydrocarbon skeleton and one or more functional groups. A functional group is an atom or group of atoms that, together with a hydrocarbon skeleton, provides characteristic properties (functional properties). Thus, in the alkyne halides the halogen atom is the functional group; in alcohols, the group -OH- and in alkenes, the carbon-carbon double bond.It should not be forgotten that the chemical reactions that are considered characteristic of these functional groups are those that are carried out in the halogen atom, or in the hydroxyl group (-OH) or in the carbon-carbon double bond. A part of the so-called organic chemistry is therefore the chemistry of the various functional groups.
Alcohols:
Alcohols are characterized by the presence of the –OH group, called the hydroxy group. The general formula for these compounds is R-OH, where R is a closed or open chain alkyl group.
Ethers:
We call ethers compounds composed of two radicals linked together by an oxygen atom, so its functional group is:
R – O – R. Radicals that bind to oxygen may be the same or different. The most common way of naming them is by putting the word ether before the name of the radicals, if they are equal, only the radical is mentioned by prefixing the prefix "di" and the ending "ico"; if they are different, the shorter chain is named first, and the same termination is added to the name of the other.
Aldehydes and Ketones:
Aldehydes and ketones are known as two types of compounds that contain in their molecule the functional group> C = O (an oxygen atom denounced to a carbon by means of a double bond); The name of this functional group is "carbonyl", and it can give rise to two types of compounds with some similarities; they are called aldehydes if the group is terminal, and ketones in case the group –C = O joins an intermediate atom. We note that the functional group for aldehydes also includes the hydrogen atom, so the group is: –CH = O. The word aldehyde is a compound word that means dehydrogenated alcohol, so these compounds can be named by changing the "ol" termination of alcohol to "al" of the aldehydes. Ketones, although they can also be dehydrogenated alcohols, change the "ol" termination of the alcohol to "one" of the ketone. The most important and common of the aldehydes is elmetanal, also known as formalin, formic aldehyde or formaldehyde. Methanal is a colorless gas with a penetrating odor and soluble in water, alcohol and ether; Its most common uses are the preservation of anatomical organs or parts, as a disinfectant and in the industry to manufacture resins, dyes, germicides and fertilizers. Some aldehydes of plant origin are added to certain products to impart smell and taste.
Amines and Amides:
Amines are organic compounds derived from ammonia (NH3). They are formed when one, two or all three hydrogen atoms of ammonia are substituted by radicals. Amines are formed from the replacement of ammonia hydrogens by radicals.
The amides are derived from the combination of amines and carboxylic acids. In all animal and vegetable proteins, the amide group is repeated thousands of times in the form of chains and in some macromolecules such as nylon. Although organic chemistry may seem very complicated because of the large number of compounds that can be formed, its study is a passionate field, in which day-to-day chemists find new compounds with new characteristics and uses.
Halogenated Compounds:
The name of the halogen is said and its position (when necessary) and then the name of the hydrocarbon, or the name of the halogen ending in uro is said after the word 'de' and subsequently the name of the alkane ending in ilo.
Carboxylic acids:
Carboxylic acids are molecules with flat trigonal geometry. They have hydrogen acid in the hydroxyl group and behave as bases on carbonyl oxygen. Melting and boiling points are high since they form dimers, due to hydrogen bonding.
The most characteristic property of carboxylic acids is the acidity of hydrogen located on the hydroxyl group. The pKa of this hydrogen ranges between 4 and 5 depending on the length of the carbon chain.
The carboxylic acids are relatively strong acids as they stabilize the charge of their conjugate base by resonance. Attractant electron substituents increase the acidity of carboxylic acids. High electronegativity groups remove charge by inductive effect of the carboxylic group, producing a decrease in the pKa of acidic hydrogen.
The inductive effect increases with the electronegativity of the halogen, with the proximity of the halogen to the carboxylic group and with the number of halogens.
The carboxylic acids can be deprotonated with bases, such as NaOH, to form the carboxylate salts.
