Properties and uses of urea formaldehyde resin
Urea-formaldehyde is chemically known as the urea-methanal .It is a non-transparent thermo setting resin or plastic and is made from urea and formaldehyde heated in the presence of a mild base such as ammonia or pyridine. The resins are very usefull in adhesives, and also in the MDF, and the molded objects.It is first time synthesized in 1884 by Hölzer, with coworker Bernhard Tollens.In 1919, Hanns John (1891–1942) of Prague, Czechoslovakia obtained the first patent for urea-formaldehyde resin.
PROPERTIES OF UREA FORMALDEHYDE RESIN
Urea-formaldehyde resin’s include-:
· It has a very high tensile strength.
· Urea formaldehyde has the property of flexural modulus.
· Has the property of heat distortion temperature.
· Has the capacity of low water absorption.
· It has the property of mould shrinkage.
· Has a property of high surface hardness.
· It can be elongated at break
· It is volume resistance in nature.
as we know about 1 million metric tons of urea-formaldehyde are produced every year and is used world wide as the data provided and Over 70% of this production is then put into use by the forest industry products and also used as a great resin for bonding particleboard (61%), medium density fiberboard (27%), hardwood plywood (5%), and laminating adhesive (7%).
USES OF UREA FORMALDEHYDE RESIN
Urea formaldehyde is the very common chemical and is mostly used because of its chemical properties. Examples are textiles, paper, foundry sand molds, wrinkle resistant fabrics, cotton blends, rayon, corduroy, etc.also used to glue wood together. Urea formaldehyde is mostly used when producing electrical appliances casing also desk lamps .
It is widely chosen as an adhesive because of its property of high reactivity, wonderfull performance and low price. It is a chemical combination of urea and formaldehyde and is not poisonous in nature. The Examples of amino resins include tires from automobile industry in order to improve the bonding of rubber to tire cord, paper for improving tear strength, molding electrical devices, molding jar caps, etc.
Urea formaldehyde is also used in agricultural field as a source of nitrogen fertilizer and Its rate of decomposition is into CO2 and NH3 and is determined by the action of microbes found naturally in soils. The activity of these microbes, and the rate of nitrogen release is temperature dependent. The optimum temperature for microbe activity is approximately about (70-90) °F.
Urea-formaldehyde foam insulation (UFFI) was used mostly in the 1970s by Homeowners .It is used as a wall cavity filler during the time for energy conservation. In the 1980s biggest concern began to evolve about formaldehyde vapor emitted in the curing process, as well as from the breakdown of old foam.
QUESTIONS AND ANSWERS
Q1. What Is Urea Formaldehyde Resin?
ANS:- Urea formaldehyde resin is an opaque chemically thermoset resin obtained by heating urea and formaldehyde in a sustain of ammonia or pyridine..
Q2. What are the uses of urea formaldehyde?
ANS:- It used vastly in adhesives, wooden carving, Medium-density fiberboard electrical components and sometimes molded into objects.IT is also known as urea-methanal.
Q3.What is high polymer?
ANS:- A substance composed a molecular weight greater than 10,000.can be said as high polymer