Presentation on Paracetamol
Department of Chemical Engineering, IIT Delhi
POLYIMIDE
SUBMITTED TO:
Dr. Sreedevi Upadhyayula
SUBMITTED BY:
Gurdeep Singh Somal 2010CH10078
Gurvineet Singh Dhillon 2010CH10079 Gaurav Singh Sinsinwar 2010Ch10077
Polyimide is a polymer of imide monomers. The structure of imide is as shown. Polyimides have been in mass production since 1955. Typical monomers include pyromellitic dianhydride and 4,4 '-oxydianiline. Polyimides are a very interesting group of incredibly strong and astoundingly heat and chemical resistant polymers. Their strength and heat and chemical resistance are so great that these materials often replace glass and metals, such as steel, in many demanding industrial applications. Polyimides are even used in many everyday applications CLASSIFICATION According to the composition of their main chain, polyimides can be:
Aliphatic (linear polyimides), Semi-aromatic, Aromatic: R ' and R" are two carbon atoms of an aromatic ring. These are the most used polyimides because of their thermostability.
According to the type of interactions between the main chains, polyimides can be:
Thermoplastic: very often called pseudothermoplastic. Thermosetting: commercially available as uncured resins, polyimide solutions, stock shapes, thin sheets, laminates and machined parts
PROPERTIES Exceptional mechanical strength Low dielectric constant Flexible Polishable to Angstrom level surface finishes Excellent dimensional stability Low water absorption High temperature stability Excellent machinability Non-contaminating Low coefficient of thermal expansion
REASON FOR ITS MECHANICAL STRENGTH The charge transfer complex between various imide monomers works between adjacent units in the polymer chain and between chains. The chains will stack together like strips of paper, with donors and acceptors paired up.
This charge transfer complex holds the chains together very tightly, not allowing them to move around
POLYIMIDE
SUBMITTED TO:
Dr. Sreedevi Upadhyayula
SUBMITTED BY:
Gurdeep Singh Somal 2010CH10078
Gurvineet Singh Dhillon 2010CH10079 Gaurav Singh Sinsinwar 2010Ch10077
Polyimide is a polymer of imide monomers. The structure of imide is as shown. Polyimides have been in mass production since 1955. Typical monomers include pyromellitic dianhydride and 4,4 '-oxydianiline. Polyimides are a very interesting group of incredibly strong and astoundingly heat and chemical resistant polymers. Their strength and heat and chemical resistance are so great that these materials often replace glass and metals, such as steel, in many demanding industrial applications. Polyimides are even used in many everyday applications CLASSIFICATION According to the composition of their main chain, polyimides can be:
Aliphatic (linear polyimides), Semi-aromatic, Aromatic: R ' and R" are two carbon atoms of an aromatic ring. These are the most used polyimides because of their thermostability.
According to the type of interactions between the main chains, polyimides can be:
Thermoplastic: very often called pseudothermoplastic. Thermosetting: commercially available as uncured resins, polyimide solutions, stock shapes, thin sheets, laminates and machined parts
PROPERTIES Exceptional mechanical strength Low dielectric constant Flexible Polishable to Angstrom level surface finishes Excellent dimensional stability Low water absorption High temperature stability Excellent machinability Non-contaminating Low coefficient of thermal expansion
REASON FOR ITS MECHANICAL STRENGTH The charge transfer complex between various imide monomers works between adjacent units in the polymer chain and between chains. The chains will stack together like strips of paper, with donors and acceptors paired up.
This charge transfer complex holds the chains together very tightly, not allowing them to move around
References: 1. 2. 3. 4. http://en.wikipedia.org/wiki/Kapton http://scholar.lib.vt.edu/theses/available/etd-051799-162256/unrestricted/polyimide1.pdf http://scholar.lib.vt.edu/theses/available/etd-04282000-15260034/unrestricted/debidunson2.pdf http://archive.org/details/NasaLangleyResearchCenterPolimideSynthesis