On Chemical Modified Polyolefins by Grafting of Polar Monomers: A Survey Based on Recent Patents Literature

摘要

The chemical modification of macromolecules, with the purpose to provide them better properties, is a topic that emerged in mid last century. Further, a little later (sixties in XX century), there were ascertained that the interfacial agents based on polymer chemically modified (or functionalized polymers) appeared as the key in order to optimize multiphase materials in terms of morphology and structure of the interfacial regions between phases. As a consequence, the scientific and technical literature based on this topic, and especially those based on grafted polyolefins, augmented exponentially. Beyond the patent laws and regulations, some major questions related to the limits of the rights protected are still open and constitute a subject of controversial. As a mere example, it can be mentioned, the protection of the equivalent substantial elements of any invention or the content and importance of the state of the art embodied in the technical document, among others. Nevertheless, the huge number of patents published in this scientific-technical field (many sponsored by leader companies from the chemical, clinical, electronic, or automotive industries) is a strong indicator of the importance of the topic. The function of the average person skilled in the art is indeed one of the most key aspects related to the patent literature and the present survey is focused on this point of view. Because of the difficulty to fully well solve the chemical structure of the chemically modified polyolefin, i.e., the number and location of the functionalities grafted onto the polymer, by using the classical finger print structural characterization techniques such as NMR, (s) NMR, FTIR spectroscopy, or x-r diffraction, several scientific questions remain open and explain the huge research efforts devoted to them. As a consequence, patents related to the topic are concerning not only to the chemical modification processes but also to the new properties (and/or uses) of these grafted polyolefins, (i.e., in compounding operations; in purification processes and/or procedures, and so on), and not to the mere protection of the fingerprint (or structure) of the chemically modified polymeric substance.