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At or near the final stages of production, the material is treated with a chain extender. Typically, chain extenders are bifunctional, i.e., they have two functional groups, which can link together two polymers. Representative classes of chain extenders are diglycidyl ethers, diols, diamines, or dianhydrides. Chain extenders are often applied ...
2-Methylpentamethylenediamine can also be used as a chain extender for polyurethane applications, and in particular with PUDs. [3] [4] Its derivatives like aspartic esters, secondary amines, aldimines and ketoimines serve as curatives in polyurea systems. In polyamides, 2-Methylpentamethylenediamine acts as a crystallinity disruptor.
1,6-Hexanediol can improve the hardness and flexibility of polyesters as it contains a fairly long hydrocarbon chain. In polyurethanes, it is used as a chain extender , and the resulting modified polyurethane has high resistance to hydrolysis as well as mechanical strength, but with a low glass transition temperature.
Water softening is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water requires less soap for the same cleaning effort, as soap is not wasted bonding with calcium ions. Soft water also extends the lifetime of plumbing by reducing or eliminating scale build-up in pipes
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.
However, the study found the chemicals the EPA regulates made up only about 8% of the potentially hazardous compounds found in the water samples analyzed. The majority comprised unregulated ...
The FDA explained that the move will help call attention to products like nuts and seeds, higher-fat fish like salmon, certain oils, coffee, tea, and water, which previously did not qualify for ...
Learn how to download and install or uninstall the Desktop Gold software and if your computer meets the system requirements.