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Polyacetylene consists of a long chain of carbon atoms with alternating single and double bonds between them, each with one hydrogen atom. The double bonds can have either cis or trans geometry . The controlled synthesis of each isomer of the polymer, cis -polyacetylene or trans -polyacetylene, can be achieved by changing the temperature at ...
Polyacrylic acid is a weak anionic polyelectrolyte, whose degree of ionisation is dependent on solution pH. In its non-ionised form at low pHs, PAA may associate with various non-ionic polymers (such as polyethylene oxide, poly-N-vinyl pyrrolidone, polyacrylamide, and some cellulose ethers) and form hydrogen-bonded interpolymer complexes. [17]
Polyacrylonitrile (PAN) is a synthetic, semicrystalline organic polymer resin, with the linear formula (CH 2 CHCN) n. [2] Almost all PAN resins are copolymers with acrylonitrile as the main monomer.
In polymer chemistry, chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule: [1] [2] + + where • is the active center, P is the initial polymer chain, X is the end group, and R is the substituent to which the active center is transferred.
Whereas an uncharged linear polymer chain is usually found in a random conformation in solution (closely approximating a self-avoiding three-dimensional random walk), the charges on a linear polyelectrolyte chain will repel each other via double layer forces, which causes the chain to adopt a more expanded, rigid-rod-like conformation. The ...
Low molecular weight poly-alpha-olefins are useful as synthetic lubricants such as synthetic motor oils for vehicles and can be used over a wide temperature range. [ 8 ] [ 10 ] Even polyethylenes copolymerized with a small amount of alpha-olefins (such as 1-hexene , 1-octene , or longer) are more flexible than simple straight-chain high-density ...
General chemical structure of a polyketone. Polyketones are a family of high-performance thermoplastic polymers. The polar ketone groups in the polymer backbone of these materials gives rise to a strong attraction between polymer chains, which increases the material's melting point (255 °C for copolymer (carbon monoxide ethylene), 220 °C for terpolymer (carbon monoxide, ethylene, propylene).
Chain extenders (f = 2) and cross linkers (f ≥ 3) are low molecular weight amine terminated compounds that play an important role in polyurea compounds, coatings, elastomers and adhesives. However, the isocyanate component is often an oligomer that is trifunctional and so the crosslinking comes from that part of the cured polymer.