Process chain size distributions

Copolymers with butadiene, ie, those containing at least 60 wt % butadiene, are an important family of mbbers. In addition to synthetic mbber, these compositions have extensive uses as paper coatings, water-based paints, and carpet backing. Because of unfavorable reaction kinetics in a mass system, these copolymers are made in an emulsion polymerization system, which favors chain propagation but not termination (199). The result is economically acceptable rates with desirable chain lengths. Usually such processes are mn batchwise in order to achieve satisfactory particle size distribution. 

A similar approach has been suggested in other studies of plant cells [57] and protein precipitates [133]. However, information on the rate of the size distribution shift process cannot be inferred from chain-length measurements made only at the beginning and end of the experiment. To date, there have been no reports on the progressive modification of the size distribution of plant cells subjected to continued exposure to turbulent forces. There are, however, a number of studies which address the break-up of mycelial hyphae in agitated vessels... 

Research on the modelling, optimization and control of emulsion polymerization (latex) reactors and processes has been expanding rapidly as the chemistry and physics of these systems become better understood, and as the demand for new and improved latex products increases. The objectives are usually to optimize production rates and/or to control product quality variables such as polymer particle size distribution (PSD), particle morphology, copolymer composition, molecular weights (MW s), long chain branching (LCB), crosslinking frequency and gel content. 

To reduce or eliminate unwanted peaks or tails in a particle size distribution curve (see Figs. 2b and 6), milling can be applied to break apart the chains of the abrasive particles. Milling is a process for continuous dispersion and wet fine grinding of solid in a liquid phase. It is essential that besides breakage of chains no other chemical reactions occur under the... 

The results of this study show that ultrasonic absorption techniques, when used in conjunction with other aggregate properties, provide important kinetic information about the partitioning process of alcohols tetween ionic micelles and the bulk phase. The effect of hydrocarbon chain length of the alcohol on the exit rates of monomer surfactant and alcohol components from the mixed micelles, aggregate size distribution, and the electrostatic stabilization of the head group region of the micelles will be considered. As well, previously unreported data for water- 1-butoxyethanol-DTAB will be used to extend conclusions based on previous work [2,3]. 

The size and structure of the microfibril are under biological control rather than being determined by classical thermodynamics. In other words biosynthetically important processes determine the size of the microfibril rather than having a varying size distribution described by a probability function. There is much evidence that individual cellulose polymer chain and microfibril synthesis is one of almost simultaneous polymerization and then crystallization (Preston, 1974 Wilson and White, 1986 Delmer, 1999). 

Especially for process control it is often necessary to determine particle size distributions of particulate solids that are in motion. The material may be transported either on or by a moving device, e.g. belt, vibrating, or drag chain, screw, bucket, and other conveyors, or in a carrier medium such as gases or liquids it may also fall freely or slide down chutes of various configurations. The best method to obtain a representative sample from such situations is to temporarily divert the entire stream into a container. If the particulate matter... 

The properties of polymers are dependent on many factors including inter-and intrachain bonding, the nature of the backbone, processing events, presence/absence of additives including other polymers, chain size and geometry, and molecular weight distribution. 

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