Which one of the following is not a condensation polymer?
Neoprene is not a condensation polymer. It is an addition polymer.
Neoprene is made from monomer chloroprene (2-chlorobuta-1,3-diene).
Dacron, Melamine and Glyptal are condensation polymers.
Dacron ( also known as terylene) is a polyester made by condensation polymerisation of ethylene glycol and dimethyl terephthalate.
Glyptal is a copolymer of ethylene glycol and phthalic acid.
Melamine ( or formaldehyde melamine polymer) is obtained from condensation polymerisation of melamine with formaldehyde.
The weakest inter-particle forces are present in:
ELASTOMERS - The polymer chains are held together by the weakest intermoleculer faces. These weak binding forces permit the polymer to be stretched.
FIBERS - Fibers have strong intermoleculer forces like hydrogen bonding. These strong forces also lead to close packing of chains and thus impact crystalline nature.
THERMOPLASTICS - They posses intermoleculer forces of attraction intermediate between elastomers and fibers.
THEMOSETTING - They are cross linked & heavily launched.
Polymers that are found in nature are called:
Natural polymers abound. Proteins, starches, carbohydrates, even DNA are natural polymers. A hamburger consists mostly of polymers. The cardboard container the hamburger came in and the napkin used to wipe up any ketchup spills are also made of polymers. Understanding natural polymers' structure, characteristics and uses can help people make environmentally conscious and informed choices.
Which polymerisation occurs among the molecules containing double bonds?
Addition polymerization takes place when the monomer molecule contains double carbon bonds, as in alkenes, or triple carbon bonds, as in alkynes. In this lesson we will consider alkene monomers.
Cotton is an example of:
Cotton is defined as a plant, or the soft cloud-like substance that comes from shrubby plants and is used to make threador cloth. An example of cotton is the stuffing inside a teddy bear.
A condensation polymer among the following is:
Decron is a condensation polymer. It is formed by the condensation of ethylene glycol and terephthalic acid.
Cellulose acetate is a:
Perhaps the "semi-synthetic" polymers that was stated in the question refers to this kind of polymers. For example, cellulose acetate is a thermoplastic polymer that is produced from cellulose, a natural polymer, rather than through polymerization reaction of a monomer. Actually, there is no polymerization reaction in the production process of polymer products like cellulose nitrate and other chemical derivatives of cellulose. So, they can be considered as semi-synthetic polymers.
Polyacrylonitrile is an example of:
Polyacrylonitrile is an example of addition polymer. The addition polymerisation of acrylonitrile in presence of a peroxide catalyst leads to the formation of polyacrylonitrile.
The polymers which are prepared in the laboratories are called:
Synthetic Polymers: Polymers are large molecules composed of repeated chemical units. The smallest repeating unit is called a mer. The term polymer is derived from the Greek words poly and mers meaning "many parts."
Which of the following is true for the resultant polymer product formed, when molecules of pthalic acid react with molecules of glycerol?
The reaction between pthalic acid and glycerol initially results into linear or branched polymer but, due to trifunctionality of glycerol, ultimately cross-linking takes place between the molecules.