Polymer processing research problems

By 1980, research and development shifted from relatively inexpensive surfactants such as petroleum sulfonates to more cosdy but more effective surfactants tailored to reservoir and cmde oil properties. Critical surfactant issues are performance in saline injection waters, adsorption on reservoir rock, partitioning into reservoir cmde oil, chemical stabiUty in the reservoir, interactions with the mobiUty control polymer, and production problems caused by resultant emulsions. Reservoir heterogeneity can also greatly reduce process effectiveness. The decline in oil prices in the early 1980s halted much of the work because of the relatively high cost of micellar processes. 

Therefore, polymer libraries, in combination with high-throughput screening techniques, are highly useful tools for the evaluation of (quantitative) structure-property relationships and/or the identification of hits of certain desired properties of the evaluated materials. These tools help researchers to understand their research problems more thoroughly by, e.g., finding optimal process conditions or product performance within a reduced amount of time and/or experimental effort. 

Important research problems in polymer processing techniques are... 

The focus of this chapter was based on the work done so far both in academia and in commercial software companies dedicated to polymer processing. Examples from some interesting and important polymer flows have been reviewed, such as those that arise from polymer processing operations with viscous (inelastic) and viscoelastic polymer melts. The topic is vast and this chapter deals exclusively with the continuum approach of flow problems. Although experimental evidence has accumulated over the years from various researchers and for various processes, the theory and predictions have lagged behind, mainly due to the complexity of the subject. 

The development of polythiophenes since the early 1980s has been extensive. Processible conducting polymers are available and monomer derivathation has extended the range of electronic and electrochemical properties associated with such materials. Problem areas include the need for improved conductivity by monomer manipulation, involving more extensive research using stmcture—activity relationships, and improved synthetic methods for monomers and polymers alike, which are needed to bring the attractive properties of polythiophenes to fmition on the commercial scale. 

Radical polymerization is often the preferred mechanism for forming polymers and most commercial polymer materials involve radical chemistry at some stage of their production cycle. From both economic and practical viewpoints, the advantages of radical over other forms of polymerization arc many (Chapter 1). However, one of the often-cited "problems" with radical polymerization is a perceived lack of control over the process the inability to precisely control molecular weight and distribution, limited capacity to make complex architectures and the range of undefined defect structures and other forms of "structure irregularity" that may be present in polymers prepared by this mechanism. Much research has been directed at providing answers for problems of this nature. In this, and in the subsequent chapter, we detail the current status of the efforts to redress these issues. In this chapter, wc focus on how to achieve control by appropriate selection of the reaction conditions in conventional radical polymerization. 

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