Chain transfer to monomer
Chain transfer reactions are usually categorized by the nature of the molecule that reacts with the growing chain. Transfer to chain transfer agent. Chain transfer agents have at least one weak chemical bond, which therefore facilitates the chain transfer reaction. Common chain transfer agents include thiols, especially … See more Chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule. P• + XR' → PX + R'• Chain transfer reactions reduce the average See more 1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "chain transfer". doi: 2. ^ Flory, P. J. Principles of … See more Chain transfer was first proposed by Taylor and Jones in 1930. They were studying the production of polyethylene [(C 2H 4)n] from See more The nature of chain transfer reactions is currently well understood and is given in standard polymerization textbooks. Since the 1980s, however, a particularly active area of research has been in the various forms of free radical living polymerizations including See more WebAug 1, 2004 · Modeling suggests that the deviations observed at high molecular weights can be explained by branching of the chains through chain transfer to the polymer, with a branching density as low as...
Chain transfer to monomer
Did you know?
WebJun 16, 2024 · Chain transfer to monomer is relatively low for many monomers but high for those with labile C–H bonds (e.g., vinyl acetate in which abstraction of a H atom from … WebFeb 5, 2024 · Saturated chain ends, instead, usually derive from chain transfer to a main group metal cocatalyst (e.g., Al and Zn alkyls) [31,32] or reaction with molecular …
WebJul 7, 2015 · Chain transfer reactions are especially prevalent in the high pressure radical polymerization of ethylene, which is the method used to make LDPE (low density polyethylene). The 1º-radical at the end of a growing chain is converted to a more stable 2º-radical by hydrogen atom transfer. WebThere are several types of chain transfer reactions; three very common reactions are: Proton transfer to monomer: a β-proton is transfered to a monomer, which becomes the …
Webchain transfer processes so that Po = y/Ri (17) where y has a value between 1 and 2 depending on the relative importance of steps (4) and (5). The ci in (16) are chain transfer constants, i.e. cxa = ktrjkp. If chain transfer to monomer and initiator occur but other transfer steps are absent then WebAdding ethers as the chain transfer agent has been found to be effective to improve the controllability to form exo-olefin end groups. 38–50 These developments are clearly discussed in the next section: development of …
WebJul 23, 2008 · Computational studies of a variety of polymerization catalyst models have revealed an unexpected fluidity in chain termination mechanisms. For many early …
Web2 days ago · Thermosetting materials generated by photopolymerization are inherently highly crosslinked and suffer from significant shrinkage stress, are often brittle, and have a limited range of mechanical properties. Various classes of chain transfer agents (CTAs) have been investigated and developed to reduce the crosslinking density of … how can i watch the movie smileWebSep 12, 2024 · Once the first monomer has been initiated into a radical, it can react with another monomer to enchain it and make a new radical. This is the principal propagation step of the chain reaction. That step will keep repeating, adding … how can i watch the movie fallWebThe chain transfer constant, C is defined as the ratio of the chain transfer and propagation rate constants; C = k tr /k p There is some C, which includes a term for transfer to a … how can i watch the movie meganWebAug 15, 2024 · The binding of a monomer to the reactive metal-carbon bond should occur in from the least hindered site. 8 As shown in Figure 15, the trans-complex in which methyl on the growing chain is trans to the methyl group on the incoming monomer, should be energetically favored than the cis-complex, as the trans-complex experience less steric … how many people have pericarditishow many people have perfect memoryWebWhile the basic free radical polymerization reactions of initiation, propagation, termination, and chain transfer are still favored, the secondary reactions begin to have a stronger impact on polymerization as the temperature rises. ... Secondary reactions significantly affect reaction kinetics in the polymerization of acrylate monomers ... how can i watch the movie singlesWebAdding ethers as the chain transfer agent has been found to be effective to improve the controllability to form exo-olefin end groups. 38–50 These developments are clearly … how can i watch the movie grease