Current Polymer Usage

Aiiowing for some variation in estimates of European consumption of polymers in Pipe applications it is generally observed that around 1.5 million tonnes of PVC are used annually and around 500 thousand tonnes of HOPE are used. PP use in various forms constitutes probably around 150 thousand tonnes. These are the dominant materials that also constitute greatest growth potential in tonnage terms. There is however scope for smaller, but profitable opportunities in speciality markets. 

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Application to Polymeric Materials.—There have been several notable examples of the application of slow-response time-domain methods to dielectric measurements of polymers. - Williams used a step-up and step-down method and calculated e"(to), via the Hamon approximation, from the average of the transient charging and discharging currents. Later usage has led to improved precision. ... 

The preferred term throughout this book is relative molar mass, but we should note that the use of this term is not common in polymer chenfistry. More often the older term molecular weight is used, both throughout the polymer industry and among acadenfic polymer scientists. This usage extends even to the current research literature. 

Plastomer, a nomenclature constructed from the synthesis of the words plastic and elastomer, illustrates a family of polymers, which are softer (lower hexural modulus) than the common engineering thermoplastics such as polyamides (PA), polypropylenes (PP), or polystyrenes (PS). The common, current usage of this term is reshicted by two limitahons. First, plastomers are polyolehns where the inherent crystallinity of a homopolymer of the predominant incorporated monomer (polyethylene or isotactic polypropylene [iPP]) is reduced by the incorporahon of a minority of another monomer (e.g., octene in the case of polyethylene, ethylene for iPP), which leads to amorphous segments along the polymer chain. The minor commoner is selected to distort... 

It will be clear from these examples that this classification is now somewhat arbitrary. Many authors still refer to addition and condensation polymers in their current, conventional sense, however, and it is therefore necessary for the informed reader to understand this usage. 

Since the early developments with polymethacrylates and polyisobutylenes, a wide variety of polymers have been explored. All of these have been developed at least to the point of commercial sampling examples are shown in Table 5.1. Five core technologies currently find important commercial usage ... 

Table VII distributes automotive topcoat usage by type, with predictions for 1987. The progression from low-solids, high-emission coatings to high-solids systems is shown. Research and development of HS-E are active at each of the auto companies and at every major coatings supplier and raw materials producer. Certainly, problems such as specific polymer design and cross-linker choice still exist—as well as application, flow, and aluminum flake orientation. However, current and future research and development should reduce these problems rapidly to manageable levels.

The second comment concerns the usage of rigid water models such as the SPC/E model [81], which by design cannot undergo ionization or react chemically. We note that actual fields considered here are much too weak to polarize significantly, let alone decompose water when any flow of electric current is prevented by proper insulation. Top end insulators like polymer and silica films with dielectric strength of up to 5 x 10 V m can provide more than adequate insulation. 

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