Weighf molecular

A wide variety of A2B monomers, such as 2,2-dimethyl propionic acid, 3,5-diacetoxybenzoic acid, 3,5-6is(trimethylsiloxy)benzoyl chloride, 3,5-dihydroxy-benzoic acid, and 5-acetoxyisophthalic acid have been used for the synthesis of hyperbranched polymers. A majority of the polymers are synthesized via step-wise polymerizations where A B monomers are bulk-polymerized in the presence of a suitable catalyst, typically an acid or a transesterification agent. To achieve satisfactory conversion, the low-molecular-weighf condensation product (e.g. H2O, CH3OH) formed during the reaction has to be removed. This is most often accomplished by passing an inert gas or by reducing the pressure in the reaction vessel. A drawback of polycondensation polymers is that they are prone to depolymerization by hydrolysis, which might restrict their use. 

Fraction Number Average Molecular Weighf Parent (wt%)... 

Higgins et al. [8] reported the application of Born-Green-Yvon (BGY) theory to predict behavior that is outside the typical range of experimenfal condifions used to obfain fhe parameters. As an example, fhe aufhors used fhe characferisfic parameters obfained by characterization of fhe blend from one sef of molecular weighfs to predicf fhe behavior of a differenf molecular... 

Dee, G.T., Ougizawa, T., and Walsh, D.J., 1992, The pressure-volume-temperature properties of polyethylene, poly(dimethylsiloxane), poly(ethylene glycol) and polyfpropylene glycol) as a function of molecular weighf , Polymer 33, 3462. 

Remember that for molecules, the mass in grams of 1 mole of molecules is equal to the molecular weight of fhe molecule obfained by adding fogefher fhe atomic weighfs of fhe atoms in fhe molecule... 

Probably the industry s best known compostable biopolymer is polylactic acid (PEA), first synthesized by DuPont s Wallace Carothers (the inventor of nylon) in 1932. However, producing a high-molecular-weighf version of this polymer proved to be a major challenge that was not successfully mef until 60 years later, when scientists at Cargill succeeded, in the course of developing a continuous production process. Usually sold as a green alternative to... 

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