What are the 3 basic structure of polymers?
The four basic polymer structures are linear, branched, crosslinked, and networked. Diagrams of linear, branched, crosslinked, and networked polymer structures.
How linear polymers are formed and what elements are link together to form a linear chain?
In linear polymers the repeating units are joined together end to end in a single flexible chain. The polymeric chains are kept together through physical attractions. These polymers have extensive Vander Waals attractions keeping the chains together.
How are polymer chains joined together?
The atoms in a polymer molecule are joined together by strong covalent bonds in long chains. There are variable numbers of atoms in the chains of a given polymer. One example of a polymer is poly(ethene).
What is the polymer structure of polypropylene?
Polypropylene is a tough, rigid and crystalline thermoplastic produced from propene (or propylene) monomer. It is a linear hydrocarbon resin. The chemical formula of polypropylene is (C3H6)n. PP is among the cheapest plastics available today.
How do polymers form?
A polymer is a large molecule made up of smaller, joined-together molecules called monomers. Monomers join together to make polymer chains by forming covalent bonds—that is, by sharing electrons. Other bonds then hold the groups of chains together to form a polymer material.
What is polymer structure?
A polymer is composed of many simple molecules that are repeating structural units called monomers. A single polymer molecule may consist of hundreds to a million monomers and may have a linear, branched, or network structure. Copolymers are polymers composed of two or more different types of monomers.
Is polyethylene a network polymer?
The high density polyethylene shown in the figure below is a good example of a linear polymer chain. When the branches on a polymer chain further react/connect with neighboring chains, the result is a network structure (ladder-like). The figure below shows a phenol-formaldehyde polymer.
How do the properties of Network polymers differ from those of linear or branched polymers?
The key difference between linear and branched polymers is that linear polymers have a linear structure without any branches whereas branched polymers have a branched structure. Polymers are giant molecules having a very large number of repeating units attached to each other via covalent chemical bonds.
What is structure of polymer?
A polymer is composed of many simple molecules that are repeating structural units called monomers. Covalent bonds hold the atoms in the polymer molecules together and secondary bonds then hold groups of polymer chains together to form the polymeric material.
What is meant by a polymer chain structure?
A carbon atom bonded to 2 hydrogen atoms can be considered a building block or unit of the polymeric chain. These units make up monomers, which are repeating units in the molecular chain structure. A series of monomers bonded together to form a molecular chain is known as a polymer.
What is the chemical structure of polyethylene?
Polyethylene chemical formula is (C2H4)n. Polyethylene is made by addition or radical polymerization of ethylene (olefin) monomers. (Chemical formula of Ethene – C2H4). Ziegler-Natta and Metallocene catalysts are used to carry out polymerization of polyethylene.
What is propylene plastic?
Polypropylene is a plastic that’s used to make everything from rugs to sour cream containers. It’s generally considered to be one of the safer plastics. The FDA has approved its use as a food container material, and there are no known cancer-causing effects associated with polypropylene.
What are the microstructural features of a polymer?
An important microstructural feature of a polymer is its architecture and shape, which relates to the way branch points lead to a deviation from a simple linear chain. A branched polymer molecule is composed of a main chain with one or more substituent side chains or branches.
What is the linear form of polyethylene?
The linear form of polyethylene (HDPE) facilitates efficient packing of chains and concomitantly has high crystallinity (70–90\%) and density (0.96–0.98 g cm −3 ). If the polymerization is allowed to continue, the linear chains get very long and a UHMWPE is achieved (4–6 million g mol −1 ).
What is the difference between homopolymers copolymers and terpolymers?
Polymer nomenclature is generally based upon the type of monomer residues comprising the polymer. Polymers that contain only a single type of repeat unit are known as homopolymers, while polymers containing two or more types of repeat units are known as copolymers. Terpolymers contain three types of repeat units.
What are the different types of polymeric materials?
Natural polymeric materials such as shellac, amber, wool, silk and natural rubber have been used for centuries. A variety of other natural polymers exist, such as cellulose, which is the main constituent of wood and paper.