Copolymers suppliers

FEP tetraethylene/hexafluoropropylene copolymer. Supplier. Fluorocarbon-Bunnel Plastics Division, Penntube Products, Mickleton, NJ. 

Microbial Considerations Preservatives should be added after the addition of acrylates copolymer Supplier Dow Corning... 

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). 

Suspension Polymerization. At very low levels of stabilizer, eg, 0.1 wt %, the polymer does not form a creamy dispersion that stays indefinitely suspended in the aqueous phase but forms small beads that settle and may be easily separated by filtration (qv) (69). This suspension or pead polymerization process has been used to prepare polymers for adhesive and coating applications and for conversion to poly (vinyl alcohol). Products in bead form are available from several commercial suppliers of PVAc resins. Suspension polymerizations are carried out with monomer-soluble initiators predominandy, with low levels of stabilizers. Suspension copolymerization processes for the production of vinyl acetate—ethylene bead products have been described and the properties of the copolymers determined (70). Continuous tubular polymerization of vinyl acetate in suspension (71,72) yields stable dispersions of beads with narrow particle size distributions at high yields. 

Growth in PVAc consumption is illustrated in Figure 3. The emulsions continue to dominate the adhesives and paint markets. It also shows the distribution of PVAc and copolymer usage by market. The companies listed in Table 10 are among the principal suppliers of poly(vinyl acetate)s and vinyl acetate copolymers, but there are numerous other suppliers. Many other companies produce these polymers and consume them internally in the formulation of products. 

Another contrarian, DSM in the Netherlands, had been a state-owned company before it became privatized, a process that began in 1989 and was completed in 1996. From its past it had inherited positions in fertilizers, industrial chemicals, and such intermediates as melamine and caprolactam as well as polyolefins, with access to basic olefins through its own crackers in Geleen, Netherlands. In 1997 DSM acquired the polyethylene and polypropylene operations of FIuls (VEBA) with the Gelsenkirchen site. The company had also diversified into elastomers, having purchased in the United States the Copolymer Rubber and Chemical Corporation, which contributed to DSM s expansion into the fields of ethylene propylene, styrene butadiene, and nitrile rubbers. DSM is also a supplier of industrial resins and engineering... 

The set of concentration differences form the basis for the error index calculation. The values for both peak height and peak area amount to around 2%. This value is quite acceptable considering that the concentration ratios used to develop the calibration parameters were based on the nominal values for the vinyl acetate concentrations in the commercial products obtained from the supplier. The vinyl acetate/vinyl chloride copolymers used in the analysis were stated to contain... 

Trade names and suppliers of commercial thermoplastic elastomers of aU types are given in Tables 5—7. Table 5. Trade Names of Thermoplastic Elastomers Based on Styrenic Block Copolymers ... 

The EDA approved PEN for food contact appiications in Aprii, 1996. PEN and PET can be blended together to make useful materials, and also PEN/PET copolymers can be produced. When PEN/PET blends are used, one is really making copolymers in the extruder. Analysis of the material that is extruded shows that transesterification reactions occur in the extruder, forming molecular bonds between PET and PEN molecules. Therefore, processing conditions are important to the quality of product one makes when using blends. Blends, as well as copolymers manufactured by polymer suppliers, can open up markets for this polyester that are not accessible to PEN alone because of its high price. While these materials have not yet been approved for food contact applications in the U.S., there appear to be no technical barriers to their approval. 

The standard contains a table of test temperatures and loads for each polymer. Polymers which have a very wide range of viscosities have up to three sets of test conditions to accommodate them. Consequently for materials such as ethylene vinyl acetate copolymer care must be taken to note the code letter (in this case B, D. or Z) in comparing different suppliers literature. 

Material Supplier Equistar Chemicals Ultrathene Copolymer Film ... 

Material Supplier/Grade DuPont Elvax EVA Copolymers for Blown Film Applications... 

In this case the problem was primarily caused by use of inappropriate material. The local supplier of acetal resins advised that acetal is not recommended for prolonged exposure outdoors, that the copolymer grades (with ethylene oxide) are better than the homopolymer, and a good UV stabiliser is essential. 

There were also attempts to calibrate the SEC columns with help of broad molar mass dispersity poplymers but this is less lehable. The most common and well credible SEC cahbration standards are linear polystyrenes, PS, which are prepared by the anionic polymerizatioa As indicated in section 11.7, according to lUPAC, the molar mass values determined by means of SEC based on PS calibration standards are to be designated polystyrene equivalent molar masses . Other common SEC calibrants are poly(methyl methaciylate)s, which are important for eluents that do not dissolve polystyrenes, such as hexafluoroisopropanol, further poly(ethylene oxide)s, poly(vinyl acetate)s, polyolefins, dextrans, pullulans, some proteins and few others. The situation is much more complicated with complex polymers such as copolymers. For example, block copolymers often contain their parent homopolymers (see sections 11.8.3, 11.8.6 and 11.9). The latter are hardly detectable by SEC, which is often apphed for copolymer characterization by the suppliers (compare Figure 16). Therefore, it is hardly appropriate to consider them standards. Molecules of statistical copolymers of the same both molar mass and overall chemical composition may well differ in their blockiness and therefore their coils may assume distinct size in solution. In the case of complex polymers and complex polymer systems, the researchers often seek support in other characterization methods such as nuclear magnetic resonance, matrix assisted desorption ionization mass spectrometry and like. 

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