Polymer Property Summary

In Table 6.2 a number of rheological and thermal properties have been tabulated for several important generic polymers. These data have been gathered from numerous sources, including the author s own measurements. The data should be used as estimates only, because measurement techniques may differ and because considerable differences in properties can occur in one particular polymer as a result of variations in molecular weight distribution, additives, thermomechanical history, etc. Actual measurement of polymer properties should always be preferred above published data. However, actual measurement is not always possible, in which case the table may provide useful information. 

Finally, some useful references should be mentioned containing data on polymer properties. Nielson s book [89] on polymer properties is an exhaustive survey of a large number of physical properties. The book by van Krevelen [41] is an excellent book on polymer properties and their relationship to chemical structure. The VDMA series on properties for polymer processing [90, 91, 95] contains a large amount of data on thermal properties [90], melt flow properties [91], and frictional properties [95]. Other useful data can be found in the yearly issues of the International Plastics Selector Books, the yearly Modern Plastics Encyclopedia, the Plastics Technology Manufacturing Handbook and Buyers Guide, etc. 

Nowadays, a substantial amount of information is available on the internet, and polymer properties are no exception. Many resin suppliers have data available on their website, and there are a number of electronic polymer databases available. One of the most useful databases is CAMPUS, acronym for Computer Aided Material Preselection by Uniform Standards. CAMPUS has become the most successful and widely used materials database for plastics. More than 25 international resin suppliers provide technical data on their products more than 100,000 copies have been distributed in Europe alone. 

Tg is the glass transition temperature Up is the crystalline melting point n is the power law index 

The data in the CAMPUS database has been obtained with uniform, standardized test methods as descriribed in ISO 10350, ISO 11403-1, and ISO 11403-2. CAMPUS is distributed free of charge to customers directly from the resin manufacturers. In fact, CAMPUS data from a number of resin suppliers can be downloaded from their websites at no cost. CAMPUS is available in five languages English, German, French, Spanish, and Italian [102]. Some of the data in this chapter are actually from this database. 

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In thip appendix, a summary of the error propagation equations and objective functions used for standard characterization techniques are presented. These equations are Important for the evaluation of the errors associated with static measurements on the whole polymers and for the subsequent statistical comparison with the SEC estimates (see references 26 and 2J for a more detailed discussion of the equations). Among the models most widely used to correlate measured variables and polymer properties is the truncated power series model... 

A summary of catalysis are provided in Table 1 while polymer properties are provided in Table 2. 

To summarize, the cost of production of NHTPB is lower than that of poly(NiMMO) or Poly(GlyN). However, NHTPB s performance is poor in comparison to them. On the basis of trials conducted so far, it seems likely that poly(GlyN) will prove to be a world leader in the field of energetic polymers. A summary of the properties of energetic binders for use with both explosives and propellants is given in Table 4.6a,b. 

Statistical segment lengths are based on a reference volume of 0.1 nm at the temperatures listed. Statistical segment lengths can be computed at other temperatures based on the assumption that Rg is independent of temperature. N.A. implies data not available. A useful summary of polymer properties is given by Fetters et al. [99]. 

In summary In this section we introduced some of the fundamental concepts starting from basic chemistry, intra- and inter-molecular interactions, polymer physics, and the nanomechanics and nanofracture mechanics of polymers. These theories can help scientists, engineers, technologists as well as other professionals understand why there is such a wide variety of properties available to polymers and even for a give polymer, different authors can give very different physical and mechanical parameters, for example, fracture stress of PVC reported in literature varies from 10 to 65 MPa. In fact, there are many factors that can lead to polymer property variation as discussed in Sections 1.1.1—1.1.7. The conclusion is that the variation of polymer properties is a combined effect of aU these factors. 

Thermal stability was determined by assessing the color of compression molded films of the polymer. A film sample was held in a convection oven for 4 hours at 200°C. Color and clarity of the aged film varied firom no ehange to yellow for different polymers. Molecular weight of the polymer was assessed by an indi-reet measurement of melt viscosity. A film sample was produeed by applying pressure to 0.5 g of polymer powder at 225°C in a press for 30 seconds. The area of the film formed by this technique was measured as an indieation of the viscosity of the polymer. A lower viseosity, i.e., lower molecular weight, polymer spread into a larger area film sample. Table 5.41 shows a summary of the PVDF polymerization conditions and the polymer properties. The data in Table 5.41 indieate that no reaction took place in the absenee of both iron and surfactant. Polymerization yield was anemie in the presence of only surfactant or iron. 

Tables 5.47 and 5.48 provide a summary of the polymerization conditions and polymer properties. Tert-amyl perpivalate was not as effective as diiso-propylperoxy dicarbonate as an initiator for the polymerization reaction due to a lower yield. Isopropanol and particularly methyl ethyl ketone had a negative effect on the polymerization reaction as evidenced by the yield (Table 5.48). Bis (ethyl) carbonate had no detrimental impact on the polymerization yield while it functions well as a chain transfer agent.

Fig. 8.22. Differences in behaviour between MCLCPs and isotropic polymers and summary of the MCLCP key properties.

In summary, then, it is necessary to measure the fiaction of crystals, the crystalline orientation factor the amorphous orientation factor and possibly the size and size distribution of crystals in order to relate polymer structure to polymer properties. Although the extent of crystallinity is generally measured using density or heat-of-fusion methods, orientation is determined with the help of optical birefringence, dichroism, sonic modulus, or x-ray diffraction [60]. The size of crystals is observed with an optical or electron microscope. 

Whenever a phase is characterized by at least one linear dimension which is small, the properties of the surface begin to make significant contributions to the observed behavior. We shall examine the structure of polymer crystals in more detail in Sec. 4.7, but for now the following summary of generalizations about these crystals will be helpful ... 

In summary, then, design with polymers requires special attention to time-dependent effects, large elastic deformation and the effects of temperature, even close to room temperature. Room temperature data for the generic polymers are presented in Table 21.5. As emphasised already, they are approximate, suitable only for the first step of the design project. For the next step you should consult books (see Further reading), and when the choice has narrowed to one or a few candidates, data for them should be sought from manufacturers data sheets, or from your own tests. Many polymers contain additives - plasticisers, fillers, colourants - which change the mechanical properties. Manufacturers will identify the polymers they sell, but will rarely disclose their... 

After a brief historical review in Chapter 1 the following five chapters provide a short summary of the general methods of preparation of plastics materials and follow on by showing how properties are related to chemical structure. These particular chapters are largely qualitative in nature and are aimed not so much at the theoretical physical chemist but rather at the polymer technologist and the organic chemist who will require this knowledge in the practice of polymer and compound formulation. 

Graft reactions on cellulosics are well studied and are well known to incorporate desired properties in polymers [61,72,73,76,77,99-102], but commercialization of the processes on cellulosics are not increasing. (Table 4 gives a summary of the techniques of grafting.) A fresh imaginative approach is required to solve this problem. 

The chapter is organized as follows in Section 8.2 a brief overview of ultrafast optical dynamics in polymers is given in Section 8.3 we present m-LPPP and give a summary of optical properties in Section 8.4 the laser source and the measuring techniques are described in Section 8.5 we discuss the fundamental photoexcitations of m-LPPP Section 8.6 is dedicated to radiative recombination under several excitation conditions and describes in some detail amplified spontaneous emission (ASE) Section 8.7 discusses the charge generation process and the photoexcitation dynamics in the presence of an external electric field conclusions are reported in the last section. 

These include cold drawn, high pressure oriented chain-extended, solid slate extruded, die-drawn, and injection moulded polymers. Correlation of hardness to macroscopic properties is also examined. In summary, microhardness is shown to be a useful complementary technique of polymer characterization providing information on microscopic mechanical properties. 

This chapter follows the organization used in the past. A summary of the electronic properties leads into reports of electrocyclic chemistry. Recent reports of studies of HDS processes and catalysts are then summarized. Thiophene ring substitution reactions, ring-forming reactions, the formation of ring-annelated derivatives, and the use of thiophene molecules as intermediates are then reported. Applications of thiophene and its derivatives in polymers and in other small molecules of interest are highlighted. Finally, the few examples of selenophenes and tellurophenes reported in the past year are noted. 

The new polymers are intermediate in composition and crystallinity between the essentially amorphous EPR and the semicrystalhne iPP. The presence of the complementary blocks of elastomers for both ethylene and propylene crystallinity should not indicate a similarity, beyond the levels of the crystallinity in the properties of the E-plastomers and the P-plastomers. The E-plastomers and the P-plastomers differ in their stmctural, rheological, as well as their thermal, mechanical, and elastic properties. In a comparison of the tensile strength and tensile recovery (tension set) from a 100% elongation for a range of P-plastomers and E-plastomers, the former have lower tension set than EPR and iPP. However, for comparative E-plastomers and P-plastomers at equivalent tensile strength, the latter have significantly better tension set. In summary, P-plastomers are tough polyolefins which are uniquely soft and elastic. 

Table 1 is a summary of current knowledge of the relationship between side group structure in polyphosphazenes and biomedically important properties. Within rather broad limits two or more of these properties can be incorporated into the same polymer by a combination of different side groups attached to the same macromolecular chain. 

A summary of the properties of the different types of dextrans available is presented in Table 25.1. Dextrans for clinical use as plasma expanders must have moleeular weights between 40000 (= 220 glucose units) and 300000. Polymers below the minimum are excreted too rapidly fiom the kidneys, whilst those above the maximum are potentially dangerous because of retention in the body. In practice, infusions containing dextrans of average molecular weights of40000,70000 and 110000 are commonly encountered. 

In summary, we have commented briefly on the microscopic applications of NMR velocity imaging in complex polymer flows in complex geometries, where these applications have been termed Rheo-NMR [23]. As some of these complex geometries can be easily established in small scales, NMR velocimetry and visc-ometry at microscopic resolution can provide an effective means to image the entire Eulerian velocity field experimentally and to measure extensional properties in elastic liquids non-invasively. 

A summary of properties of chain growth and step growth polymers can be found in Table 2.4. 

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