Polymers

News Polymers

• WITec appoints new distributor in Israel

  WITec, worldwide leader in nano-analytical microscopy systems, has appointed Advanced Technological Solutions Ltd. (ATSL) as its exclusive distributor in Israel. From now on ATSL will support WITec’s market entry and promote the full product line of high-resolution SNOM, AFM and Raman Imaging soluti more

• Novozymes develops fungus to produce biochemicals

  Novozymes has succeeded in developing a fungus that enables production of malic acid from renewable raw materials instead of oil. Malic acid is used as a flavor enhancer in the food industry and can be converted into other chemical derivatives used for a variety of plastic, polymer and resin product more

• New technology allows lenses to change color rapidly

  A University of Connecticut scientist has perfected a method for creating quick-changing, variable colors in films and displays, such as sunglasses, that could lead to the next hot fashion accessory.The new technology also has captured the interest of the U.S. military as a way to assist soldiers wh more

White papers Polymers

• Asymmetric Flow Field Flow Fractionation (AF4) - A Powerful Method for Polymer Characterization

  The AF4-MALS combined technique can serve as a routine method for polymer analysis and characterization. AF4 provides separation efficiency entirely comparable with traditionally used and so far dominating SEC. In addition, it yields superior separation of branched polymers, polymers containing ultra high molar mass fractions up to at least 108 g/mol, and nanoparticles. This contribution outlines the theoretical background of the method and shows several examples of its use, e.g. separation of high molecular weight polymers and particles. While SEC will certainly continue to be the most frequently employed method of polymer analysis, for many samples the description of molecular structure is more detailed if both SEC and AF4 are used. The possibility to run both SEC and AF4 on the same experimental set-up makes the AF4 method a powerful and versatile tool for the characterization of a variety of synthetic and natural polymers and related materials. more

• Polyolefins: Determination of Molecular Weight and Branching Structure by GPC/SEC

  Polyethylene and Polypropylene are so-called Polyolefins. They are produced in large amounts every year. Depending on the process and catalyst used linear or branched polymers can be produced. In case of e. g. Polyethylene there are at least three polymer types: HDPE (High Density Polytheylene), LDPE (Low Density Polyethylene) and LLDPE (Linear Low Density Polytehylene). HDPE and LLDPE are made of linear or only slightly branched macromolecules with a high level of crystallinity. They form a dense structure in the final product. LDPE is made of highly branched molecules that form a final structure with low density due to a low degree of crystallinity. more

• Do you see the complete picture?
  

  Gel permeation chromatography (GPC) or also named size exclusion chromatography (SEC) is the most often used method for determining the molecular weight of natural and synthetic macromolecules. One specific strength of this method lies in the fact that by the separation process the whole molecular weight distribution is obtained. The molecular weight distribution contains much larger information for the characterization of polymer samples compared to a single value. more

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