Alternative Polymer Formulations

Various attempts have been made to improve the rate of oxidation of PAN precursors  

An active cyclization catalyst will have the function of reducing the exothermicity of the reaction, enabling higher temperatures to be used, thus increasing the rate of O2 diffusion. 

Grassie suggested the use of a low concentration of a material that would form free in the fiber. Peracetic acid or an azo compound will decompose slowly at 180-200°C and eliminate the slow rate determining initiating step such as  

A 3% application of p-toluenesulfonic acid increased the burn-up temperature from 250° to 265°C, enabling the residence time to be reduced. 

Basic Structure Crystal orientation Crystallite content Homogeneity Precursor Polymer composition Appropriate fiber tension High density and compactness Prevent filament coalescence 

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An interesting variation on the hilayer resist concept is the chemical amplification of resist lines (CARL) process, developed at Siemens (see Fig. 17.8). In the CARL process, a top imaging layer resist formulated from an alternating polymer of maleic anhydride and an appropriate monomer, depending on the... 

Another important class of modified epoxy resins, known as epoxy acrylates, are reaction products of a low MW epoxy resin and acrylic acid or methacrylic acid, which are used in radiation curable systems. The acrylate functionality is 2, but higher functionality variants can also be prepared by using epoxy phenol novolac in place of BPA epoxy resin. Radiation curable formulations from these oligomers provide a better balance of properties and cost compared to some of the alternative polymer systems. 

There is good agreement between the SL solutions (solid lines) and the FD reference solutions (open circles). The initial difference in oil rate is caused by the compressible formulation in the FD code, whereas our SL implementation is strictly incompressible. The comparison for the pure waterflood and the continuous polymer injection is surprisingly good, despite the very different numerical approaches. For example, the FD simulator is run in fully implicit mode, whereas the SL simulator takes 100-day timesteps, meaning that the velocity field and thus the SLs are updated only every 100 days. The difference is more evident for the water-alternating-polymer solution (Fig. 10c), in which the FD simula-... 

Pike Research. Green chemistry biobased chemicals, renewable feedstocks, green polymers, less-toxic alternative chemical formulations, and the foundations of a sustainable chemical industry (Executive Summary Reprint), Ind. BiotechnoL, 2011, 7,431 33. 

Moisture-Curing Silicones. The formulation of moisture-curing sHicones includes a sHicone polymer, filler, a moisture-reactive cross-linker, and sometimes a catalyst. The most common sHicone polymer used in sealant formulations is an alternating sHicon—oxygen backbone with methyl groups attached to the sHicon such as the sHicone polymer (1). 

When the same monomer is used to build up a polymer, it is termed a homopolymer. Copolymers have two different monomers or functional groups, and terpolymers have three groups. There are even tetrapolymers available. These polymers may be further classified, for example, as random, graft, or block copolymers. Block copolymers, which have alternating sections of specific molecular chains, are used in BW formulations (but are more commonly found in CW programs). 

Traditionally, UV curable polymers have been utilized as coatings for wood and vinyl floors, but their applications have increased dramatically over the last twenty years to encompass many diverse areas, including optical fiber coatings (7), adhesives (2), disc replications (3-5), and microelectronics (6). This widespread use of UV cross-linked systems is attributed to their rapid, energy efficient curing and their solvent free, one piece formulations. Typically, UV curable systems require only a small fraction of the power normally utilized in thermally cured systems and their solvent free nature offers an environmentally safer alternative. 

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