Quantitative structure-property relationships copolymers

Potyrailo, R. A. McCloskey, P. J. Wroczynski, R. J. Morris, W. G., High-throughput determination of quantitative structure-property relationships using resonant multisensor system Solvent-resistance of bisphenol a polycarbonate copolymers, Anal. Chem. 2006, 78,... 

Determination of Quantitative Structure-Property Relationships of Solvent Resistance of Polycarbonate Copolymers Using a Resonant Multisensor System... 

Abstract In sensor and microfluidic applications, the need is to have an adequate solvent resistance of polymers to prevent degradation of the substrate surface upon deposition of sensor formilations, to prevent contamination of the solvent-containing sensor formulations or contamination of organic liquid reactions in microfluidic channels. Unfortunately, no comprehensive quantitative reference solubility data of unstressed copolymers is available to date. In this study, we evaluate solvent-resistance of several polycarbonate copolymers prepared from the reaction of hydroqui-none (HQ), resorcinol (RS), and bisphenol A (BPA). Our high-throughput polymer evaluation approach permitted the construction of detailed solvent-resistance maps, the development of quantitative structure-property relationships for BPA-HQ-RS copolymers and provided new knowledge for the further development of the polymeric sensor and microfluidic components. 

Fig. 19.1 Composition space of BPA-HQ-RS copolymers evaluated using high-throughput sensor-based system. Data points signify materials that were employed to build quantitative structure-property relationships. Numbers are percent of monomers...

Effects of Repeat Unit Sequence Distribution and Specific Interactions. Most theories and quantitative structure-property relationships for Tg only consider the case of a random distribution of repeat units along the polymer chains in treating copolymers. They give equations which predict a monotonic change of Tg between the Tg values of the homopolymers of the constituent repeat... 

Acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acry- late (ASA) are rubber-toughened plastics based upon the styrene-acrylonitrile (SAN) copolymer matrix. The combination of the stiffness and toughness exhibited by these materials has made them increasingly attractive in engineering applications, and the activity of the patent literature testifies to a continuing interest in improving properties through modifications of structure. The aim of this paper is to discuss a quantitative approach to structure-property relationships in ABS and ASA polymers. 

Near-quantitative conversion of monomer to polymer is standard in these polymerizations, as few side reactions occur other than a small amount of cychc formation common in all polycondensation chemistry [41]. ADMET depolymerization also occurs when unsaturated olefins are exposed to pressures of ethylene gas [42,43]. In this case, the equilibriiun nature of metathesis is shifted towards low molecular weight products under saturation with ethylene. Due to the high catalytic activity of [Ru] and the abihty of [Mo] and [Ru] to create exact structures, ADMET has proven a valuable tool for production of novel polymer structures for material applications as well as model copolymer systems to help elucidate fundamental structure property relationships [5]. 

Studies of the dependence of EEC properties obtained as above on the formation method showed that the precipitated finely dispersed rubber that is not bonded to the epoxy matrix does not endow it with high mechanical characteristics. When reactive oligomers are applied with high-temperature cure, there is a sharp enhancement of the modifying efficiency, accounting for the more intensive separation of the phases in the system and for the increase of the yield of the epoxy rubber copolymer. Thus, the structure and properties of epoxy resins modified by rubbers are mainly determined by the mode of system curing, but the quantitative relationships between curing mode and final properties have not been sufficiently studied. 

Depending on the chemical structure of the starting monomers, their mutual quantitative relationship and the method of conducting the reaction one can obtain copolymers of different composition and different properties. Physicochemical properties of copol5miers depend on their composition, but in most cases the relationship is not additive. Often the introduction to macromolecule during the copolymerization of a relatively small amount of another monomer provides the polymer with completely new properties. As an example one can cite a copolymer of isobutylene with a small amount (0.6-3. 0%) of isoprene. In this way the formed polymer gets properties of rubber and can be vulcanized with sulfur, while the pol5dsobutylene does not have such a capacity. 

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