Search results
Results from the WOW.Com Content Network
Epoxide monomers may be cross linked with themselves, or with the addition of a co-reactant, to form epoxy; BPA is the monomer precursor for polycarbonate; Terephthalic acid is a comonomer that, with ethylene glycol, forms polyethylene terephthalate. Dimethylsilicon dichloride is a monomer that, upon hydrolysis, gives polydimethylsiloxane.
Polymer nomenclature is generally based upon the type of monomer residues comprising the polymer. A polymer which contains only a single type of repeat unit is known as a homopolymer, while a polymer containing two or more types of repeat units is known as a copolymer. [22] A terpolymer is a copolymer which contains three types of repeat units ...
The light may be absorbed either directly by the reactant monomer (direct photopolymerization), or else by a photosensitizer which absorbs the light and then transfers energy to the monomer. In general, only the initiation step differs from that of the ordinary thermal polymerization of the same monomer; subsequent propagation, termination, and ...
Given that mixed-linkage glucan is a non-branched homopolymer of glucose, there is no side-chain synthesis, only the addition of glucose to the backbone in two linkages, β1-3 and β1-4. [10] Backbone synthesis is mediated by enzymes in cellulose synthase-like protein families F and H (CSLF and CSLH), specifically glucan synthase.
To make polyoxymethylene homopolymer, anhydrous formaldehyde must be generated. The principal method is by reaction of the aqueous formaldehyde with an alcohol to create a hemiformal, dehydration of the hemiformal/water mixture (either by extraction or vacuum distillation) and release of the formaldehyde by heating the hemiformal.
A step-growth copolymer -(-A-A-B-B-) n - formed by the condensation of two bifunctional monomers A–A and B–B is in principle a perfectly alternating copolymer of these two monomers, but is usually considered as a homopolymer of the dimeric repeat unit A-A-B-B. [6] An example is nylon 66 with repeat unit -OC-( CH 2) 4-CO-NH-(CH 2) 6-NH ...
It is a synthetic acrylate polymer derived from ethyl acrylate monomer. The polymers are colorless. This homopolymer is far less important than copolymers derived from ethyl acrylate and other monomers. It has a low glass-transition temperature about -8 °C (20 °C). [clarification needed]
The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. [1] [2] [3]For a homopolymer, there is only one type of monomeric unit and the number-average degree of polymerization is given by ¯ ¯ = ¯, where ¯ is the number-average molecular weight and is the molecular weight of the monomer unit.