Safety issues, 694 Polymer

Health and Safety Issues. Polyesterether elastomers derived from dimethyl terephthalate, butanediol, and Ptmeg are not hazardous according to the published Materials Safety Data Sheets (MSDS) for this elastomer. Polymers of a similar structure containing isophthalic acid are also not considered hazardous. For other copolymer elastomers, the MSDS put out by suppliers should be consulted by potential users before evaluation. One environmental advantage of thermoplastic elastomers of this type is that they are melt-reprocessible and thus scrap and off-specification material and even obselete parts can be easily recycled. Up to 25% by weight of recycled material can be incorporated (see Recycling, plastics). 

Several existing protocols require a solvent (acetone, methanol, isopropanol) rinse as part of equipment decontamination for VOC sampling and 1 10 percent hydrochloric or nitric acid rinse for metal analysis sampling (DOE, 1996 USACE, 1994). These practices, successful as they may be in removing trace level contaminants, create more problems than they are worth. Organic solvents are absorbed by the polymer materials used in sampling equipment construction and appear as interferences in the VOC analysis. Acid destroys the metal surfaces of soil sampling equipment and induces corrosion. The use of solvents and acids is a safety issue and it also creates additional waste streams for disposal. 

A large number of publications are available on paints and coatings, plastics and concrete. Unfortunately, the information available on polymeric construction products is scattered in journals, society reports and huge tomes which cover various technologies. This has tended to confuse and befuddle rather than enlighten the uninformed user. In this book an attempt has been made to present information on the chemistry of polymers, specific polymer systems in construction and health and safety issues. 

Chapter 2 covers the chemistry of polymers, keeping in view the chemistry involved in construction products. Chapters 3-9 detail specific polymer systems. Health and safety issues have also been covered in a general way. It is important to maintain that these general comments are for guidance only any product should be used only in accordance with... 

In order to match the safety issues, future pressure vessels include three layers an inner polymer liner, overwrapped with a high-strength and high-elasticity carbon fiber composite, and an outer layer of an aramid-material capable of withstanding mechanical and corrosion damage [107],... 

Wetzel, M.D. (2008) Environmental, health and safety issues and approaches for the processing of polymer nanocomposites. Proceedings of the 66lh SPE ANTEC, vol. 54, pp. 247-251. 

The selection of a heat stabiliser requires consideration of the precise processing operation and its temperature range, the effect of the stabiliser on melt rheology, its compatibility with the polymer formulation as a whole, possible plate-out, and its effects on ultimate properties, cost, and health and safety issues. Several heat stabilisers have been criticised on environmental grounds. 

In PAFCs the protic electrol3d e phosphoric acid is impregnated in a porous separator, e.g. silicon carbide. Thus, considerable amounts of free (highly concentrated) phosphoric acid are present in the cell, which can be a safety issue for certain applications. In case of HT-PEMFCs the protic electrolyte phosphoric acid is adsorbed in a temperature-resistant polybenzimidazole-t) e (PBI) polymer membrane. 

Perhaps most important is the confluence of these two market needs the most advanced safety features, such as ceramic or high temperamre polymer coatings, come at a premium in cost. And the least expensive separators do not have these features, and in addition, are often made with fewer quality checks and at higher production speeds, leading to questions about quality that could lead to safety issues. 

In the foregoing we have presented a general framework for sustainable polymer reaction engineering. Its most important characteristic lies in the concerted multidisciplinary approach, rather than focusing on individual competencies. Given the volume of polymer production, it will be of major importance that environmental and safety issues become an integral part of the development process. In combination with tools such as life cycle analysis and product-inspired PRE, this will allow the development of sustainable new polymer processes. 

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