Polymers, laboratory experiments

The thermodynamic point of view developed in this review and in our original works with regard to the behavior of SAH in laboratory experiments and in soil models can pave, in our opinion, the most rational way for achieving the optimal results. Based on the existing theory of network polymers, this concept is undoubtedly open to further improvement that would expand its prognostic potentialities. 

An extruder for a polymer was controlled by a microprocessor based data acquisition and control system. The CAMILE system (Control And Monitoring Interface for Laboratory Experiments) connects the sensors and control elements of the extruder to a host MS-DOS computer. While a variety of variables are measured and controlled, this paper will consider only temperature control. 

The state of the art in chemical oil recovery has been reviewed [1732]. More than two thirds of the original oil remains unrecovered in an oil reservoir after primary and secondary recovery methods have been exhausted. Many chemically based oil-recovery methods have been proposed and tested in the laboratory and field. Indeed, chemical oil-recovery methods offer a real challenge in view of their success in the laboratory and lack of success in the field. The problem lies in the inadequacy of laboratory experiments and the limited knowledge of reservoir characteristics. Field test performances of polymer, alkaline, and micellar flooding methods have been examined for nearly 50 field tests. The oil-recovery performance of micellar floods is the highest, followed by polymer floods. Alkaline floods have been largely unsuccessful. The reasons underlying success or failure are examined in the literature [1732]. 

The Scholars, working with their mentors, did an outstanding job during their residencies, and many laboratory experiments and new lecture snapshots were developed. Lecture snapshots are short discussions of timely or fundamental polymer topics. They are designed to minimize the time necessary for faculty to familiarize themselves with the topic and to prepare their presentation on it In general, the lecture snapshots require only a few minutes of lecture time and setup and interface with topics that already are covered in general chemistry courses. The snapshot format is as follows ... 

NSF funded polymer science modular experiments are now available from Eli Pearce. There are 15 of these modules for use with an introductory polymer science course or for use with a separate beginning polymer laboratory course. 

Paint formulations consist of a binder (a natural or synthetic polymer or drying oil), a solvent, and a pigment or colorant, including an extender, typically calcium carbonate or a silicate. Because of the reactivity of organic polymers toward ozone, it is not surprising that ozone damage has been observed, at least in laboratory experiments. In 1968,... 

In the case of students, this laboratory manual provides examples of the synthesis of the major classes of polymers along with a separate section on polymer characterization experiments and techniques widely used by industrial researchers. Most of the preparations and characterization experiments have been student tested and reviewed by Professor Eli Pearce at the Polytechnic University. 

E. M. Pearce, C. E. Wright, and B. K. Bordoloi, Laboratory Experiments in Polymer Synthesis and Characterization, Pennsylvania State University, University Park, PA, 1982. 

More refined laboratory experiments have provided good evidence that many of the chemical components of living cells, including polypeptides and RNA-like molecules, can form under these conditions. Polymers of RNA can act as catalysts in biologically significant reactions (as we discuss in Chapters 26 and 27), and RNA probably played a crucial role in prebiotic evolution, both as catalyst and as information repository. 

Recently, there has been a marked development in the methodologies to observe and manipulate single biopolymers (Mehta et al., 1999 Arai et al., 1999 Cui and Bustamante, 2000 Liphardt et al., 2001). The key procedure in the successful manipulation of single biopolymers has been the tight attachment of the end of the polymer to a micrometer-sized object. To achieve a wider application of such single-molecular technology, it would be important to manipulate individual macromolecules and control their conformation without any structural modifications (Chiu and Zare, 1996 Brewer et al., 1999). Thus, the manipulation of the compact DNAs without the attachment to a micrometer-sized bead or to any other macroscopic objects is expected to be useful for micrometer-scale laboratory experiments. This manipulation will also be a powerful tool for lab-on-a-chip or lab-on-a-plate (Katsura et al., 1998 Yamasaki et al., 1998 Matsuzawa et al., 1999, 2000). It may of value to refer to a recent study in transporting a compact DNA into a cell-sized liposome (Nomura et al., 2001). 

This experiment is another example of a step-growth polymerization, one that produces a crosslinked polymer. Two liquids are mixed, beginning the chemical reactions that cause polymerization and foam generation. The result is a hard polyurethane foam, similar to the material commonly used for insulation, for flotation in boats and canoes, and in furniture. This activity works well either as a laboratory experiment or as a demonstration. ... 

Density is always introduced sometime in the early weeks of the first-year chemistry course. Traditional laboratory experiments have students determining the density of water or ethanol. Teachers usually set up a density column with various liquids and solids to demonstrate differences in density. Why not substitute Densities for this experiment It has directions on setting up a polymer density column, and the students can use part one of the experiment to understand the concept of density. This can be a second density experiment after the traditional experiment. The students can be presented with the solutions of various densities and several samples of known polymers and an unknown polymer. (Some scientific supply companies sell polymer samples to be used for specific gravity experiments. Used in density experiments, they eliminate the problems of floating or air bubbles.) Ask students how density would be used to sort the polymer samples. This can be a more open-ended experiment and may prove somewhat challenging but would be excellent, especially for honors students. 

Baker anhydrous sulfur dioxide of 99.98% purity was used without further purification. Sulfur dioxide was passed through the respective monomers, kept at 0-5°C., and the dissolved S02 content was determined iodometrically in each case, running a control experiment side by side. tert-Butyl hydroperoxide (TBHP), supplied by the Monomer-Polymer Laboratories of the Bordeh Chemical Co., was used as obtained without further purification. 

In laboratory experiments S-MIF has been observed in photolysis of SO2 [14,15] and CS2 [19], but negligible to only very slight MIF is seen in H2S photolysis [20]. Elemental sulfur (Sei), or a CS c polymer in the case of CS2, is produced in all three photolysis experiments by a complex sequence of photolysis, bimolecular and trimolecular gas phase reactions, and wall reactions. Comparison of absorption spectra for SO2, H2S and CS2 reveals vibronic structure in SO2 and CS2 spectra but very little structure in the H2S spectrum (Figure 5.1), and suggests that the act of photodissociafion of the parent gas could be the source of S-MIF for SO2 and CS2. 

The excess heats of mixing experiments were performed using a modified McGlashan calorimeter. All the dynamic mechanical analyses were conducted using a Polymer Laboratories instrument at a frequency of 10 Hz and a heating rate of 2 C per minute. 

---