Polymer chemistry or macromolecular chemistry addresses the structure, characteristics and manufacture of polymers.
Table of contents
- Polymers and polymer chemistry
- Plastics analytics - the art of analysing polymers
- Natural and synthetic polymers
Polymers and polymer chemistry
Polymers are chemical substances that consist of macromolecules – that is molecules with a high molar mass with recurring structural elements. They occur naturally, but are also extensively manufactured synthetically. In the latter situation, the polymers are often generally termed plastics.
In polymer chemistry, chemists address the synthesis of polymers as well as the identification of their structure and characteristics. An important part of polymer chemistry or polymer science is the modification of organic and inorganic polymers to change the characteristics of the related plastics to the technical requirements of industry.
the art of analysing polymers
Polymers are indispensable constituents of numerous components and products from medical technology, through consumer articles, to the automotive industry. Here polymers must often withstand high loads. To make sure these requirements are met, our experts from the specialist area Chemical analytics acquire, quantify and evaluate your polymer materials and products using plastics analytics. We combine various analytical methods to analyse thermoplastics, thermosetting plastics, elastomers, composite materials and foams for their technical and chemical characteristics, e.g.:
- RAMAN and FTIR spectroscopy
- SEM-EDX (scanning electron microscopy)
- Gas chromatography with coupled mass spectrometry
- Thermogravimetry (TGA); coupling with FTIR and GC-MS possible
- Differential scanning calorimetry (DSC)
- Karl Fischer titration (KFT)
Based on these methods, our experts provide you with information about the type of polymer, filler material, the melting and crystallisation behaviour and much more. Do you want to know what we can do for you?
Then simply call us and we will provide specific advice.
Natural and synthetic polymers
Natural polymers, also called biopolymers, are the building blocks of all organisms in nature. Here proteins and polysaccharides such as cellulose and starch are particularly worthy of mention, as well as the nucleic acids from which the DNA of all life is built. Natural polymers such as hair or fur, silk or cellulose fibres (cotton) are among the oldest materials known to man.
Semi-synthetic polymers are produced by chemically processing natural polymers; during this processing the natural monomers are modified such that the end product has the specific characteristics required. Today the most important commercially is vulcanised rubber. Celluloid was one of the first semi-synthetic polymers, however today it is only of historical significance.
Our modern world is practically inconceivable without synthetic polymers; there is practically no industrial sector where they are not used. They are synthesised using various chemical reactions, collectively termed polyreactions or polymerisation, from cracked naphtha, that is from a crude oil derivative.
The numerous different requirements have resulted in a broad range of plastics with different characteristics. DIN 7724 brings order to this area by classifying polymers into various groups according to their physical behaviour at room temperature and when subject to heat.
As soon as they have cured after manufacture, thermosetting plastics, which are actually correctly called duromers, cannot be further deformed – not even by heating them up again because their macromolecules are closely cross-linked. Thermosetting plastics are of major importance in the automotive sector. For example, brake pads, bodywork and engine compartment parts are made using thermosetting plastics.
Unlike duromers, elastomers can be deformed. They deform under the action of tensile and compressive loads, but afterwards return to their original shape. Elastomers are used in many areas, for instance in the manufacture of tyres or rubber belts.
The macromolecules in thermoplastics consist of manomers with little branching, for this reason the bonds between the individual molecules are very weak. As a result they can be deformed by applying heat; this process can be repeated as often as necessary. These plastics can also be welded. Well-known and widely used plastics such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) or polyvinyl chloride (PVC) are thermoplastics.
A sub-group of thermoplastics is high-performance plastics that meet higher requirements than ordinary technical plastics because they have, for example, greater thermal and chemical resistance. However, as a rule they place higher requirements on processing.
Thermoplastic elastomers behave at room temperature like elastomers, however they can be subjected to plastic deformation by heating; they therefore combine the characteristics of elastomers and thermoplastics. These materials are used above all for seals and cable sheaths, however also for so-called soft-touch handles as are to be found on tools and consumer products such as toothbrushes or razors.
Electrically conductive polymers
polymers are doped to make them electrically conductive, the term conductive polymers is used. Today these polymers are indispensable in many applications. Polymers produced in this manner are an important element of lithium-polymer batteries, as used for example in electric mobility. They are also essential in OLED displays, fuel and solar cells.