Infrared Spectroscopy molecular weight average

Near infrared spectroscopy was used for control of molecular weight averages and monomer conversion in styrene solution polymerizations [29]. Kalman filters were used to provide real-time estimates of the process states and initiator feed rates and reaction temperatures were manipulated to allow for attainment of specified monomer conversion and... [Pg.354]

Hydrogenation of polybutadiene converts both cis and trans isomers to the same linear structure and vinyl groups to ethyl branches. A polybutadiene sample of molecular weight 168,000 was found by infrared spectroscopy to contain double bonds consisting of 47.2% cis, 44.9% trans, and 7.9% vinyl. After hydrogenation, what is the average number of backbone carbon atoms between ethyl side chains ... [Pg.67]

Nuclides, reaction with monomers, 14 248 NuDat database, 21 314 Nukiyama-Tanasawa function, 23 185 Null-background techniques, in infrared spectroscopy, 23 139-140 Number-average molecular weight, 20 101 of polymers, 11 195, 196 Number density, of droplets, 23 187 Number of gas-phase transfer units (Nq), packed column absorbers, 1 51 Number of overall gas-phase transfer units (Nog), packed column absorbers, 1 52 Number of transfer units (Nt, NTU), 10 761... [Pg.638]

A 21.3-g sample of poly(hexamethylene adipamide) is found to contain 2.50 x 10-3 mol of carboxyl groups by both titration with base and infrared spectroscopy. From these data the polymer is calculated to have a number-average molecular weight of 8520. What assumption is made in the calculation How can one experimentally obtain the correct value of M ... [Pg.195]

Tn the previous papers of this series (1, 2, 3, 4) calibration and repro- ducibility of gel permeation chromatography (GPC) have been extensively examined. This paper describes the application of GPC to two selected samples of linear polyethylenes, one having a narrow molecular weight distribution (NMWD) and another a broad molecular weight distribution (BMWD). These samples were distributed by the Macro-molecular Division of IUPAC (5) for the molecular characterization of commercial polymers. The average molecular weights by GPC are compared with the data obtained from infrared spectroscopy, osmotic pressure, melt viscosity, and intrinsic viscosity. Problems associated with data interpretation are discussed. [Pg.104]

FIGURE 6.14 Proposed scheme for control of copolymer composition and average molecular weights in semibatch methyl methacrylate/butyl acrylate emulsion copolymerizations. Reprinted (adapted) with permission from Vieira RAM, Sayer C, Lima EL, Pinto JC. Closed-loop composition and molecular weight control of a copolymer latex using near-infrared spectroscopy. Ind Eng Chem Res 2002 41 2915-2930. 2002 American Chemical Society. [Pg.127]