Polymer blends, property tailoring

A wide variety of additives and modifiers are incorporated into polymers and polymer blends to tailor specific properties. Unfortunately, these additives can also impact the colorability to the total resin system. Listed below are some common additives and modifiers used in polymers and a short discussion of their typical effect on colorability. 

It has been shown that miscible polymer blends and copolymerization offer complementary routes to polymer systems of tailored properties. The recognition that miscibility (at least in a transient sense) is much more common with aromatic heterocyclic polymers than is observed with low temperature flexible... 

The motivations for blending LCPs with conventional polymers or with other LCPs are the same elements which make blending an attractive polymer modification option. These include cost-reduction, property tailoring, accelera-... 

Reichelt N, Stadlbauer M, Folland R, Park CB, Wang J (2003) PP-blends with tailored foam-ability and mechanical properties. Cell Polym 22 315-327... 

A wide variety of polymeric membranes with different barrier properties is already available, many of them in various formats and with various dedicated specifications. The ongoing development in the field is very dynamic and focused on further increasing barrier selectivities (if possible at maximum transmembrane fluxes) and/ or improving membrane stability in order to broaden the applicability. This tailoring of membrane performance is done via various routes controlled macro-molecular synthesis (with a focus on functional polymeric architectures), development of advanced polymer blends or mixed-matrix materials, preparation of novel composite membranes and selective surface modification are the most important trends. Advanced functional polymer membranes such as stimuli-responsive [54] or molecularly imprinted polymer (MIP) membranes [55] are examples of the development of another dimension in that field. On that basis, it is expected that polymeric membranes will play a major role in process intensification in many different fields. 

Finally, it has been stated that this new toughening technique can be safely extended to other fragile plastics, such as PVC and PS (38). This observation supports that a properly tailored diblock copolymer can help in generating materials with highly improved properties. Engineering polymer blends... 

The desired compatibilization can be obtained by different methods such as the addition of a third component (copolymer or functional polymer) or by inducing in situ chemical reactions (reactive blending) among blend components, leading to the modification of the polymer interfaces and tailoring the blend phase structure and the final properties. The final properties of a blend will be determined not only by the components properties but also by the phase morphology and the interface adhesion, both of which determine the stress transfer within the blend and its end-use applications. 

The physical mixing of two or more polymers to crate a material with properties different from each of the components has become an increasingly popular route to new materials development. The resulting blend or alloy greatly reduces the associated time and costs while permitting improved processibility and enhanced properties tailored to specific application areas. Many commercial examples of two-phase polyblends consist of a matrix polymer impact modified by the addition of rubber particles. Recently, however, TLCPs have received increasing attention in the scientific and technical literature as in situ reinforcements in polymer blends and microcomposites. The matrices examined in the literature include polyimides, PES, PEI, PEEK, polycarbonate, PET, PPS, and polyarylate. 

In the development of polymeric materials, matrix polymer is the most important raw material used. Polymers are complex materials and require exhaustive consideration because many properties can be achieved by selection of polymer or polymer blending can be used to obtain a special set of properties required for application. Chapter 2 is all devoted to PVC, which is the major polymer used in PVC Formulary. Different grades, which are available commercially are discussed to facilitate selection of polymer for different purposes. Characteristics of polymer grades depend on the method of production, specifically on the type of polymerization, each having strong influence on polymer morphology and composition. But properties are also tailored to the potential applications, variety of which is illustrated by Figure 1.1. 

Polymer blends, i.e. mixtures of two or more polymeric components, are of increasing commercial importance for a number of applications. The advantage of polymer blends is the useful combination of the properties of the components without creating chemically new polymers. This approach in many cases is more feasible than developing new tailor-made polymer structures. 

Polymer blends are expected to create many useful novel materials with specific properties that cannot be achieved by individual polymers in the future. And blending is an easy and inexpensive method of modifying various properties of polymer. A polymer blend or polymer mixture is a kind of material analogous to metal alloys, in which at least two polymers are blended together to create a new material with tailored physical properties, which can be broadly divided into three categories immiscible, compahble, and miscible polymer blends. The immiscible blends are made of two polymers, and two glass transition temperatures will be observed. Compatible polymer blends are immiscible polymer blends that exhibit macroscopically uniform physical properties. The macroscopically uniform properties are usually... 

The advantage of blending bacterial plastics with other polymers is to offset the relatively high cost and to further improve the physical properties, tailoring the plastic to a specific performance-cost profile (Table 3). 

Brotherston, I.D., D.S.K. Mudigonda, J.M. Osborn, J. Belk, J. Ghen, D.G. Loveday, J.L. Boehme, J.R Ferraris, and D.L. Meeker. 1999. Tailoring the electrochromic properties of devices via polymer blends, copolymers, laminates and patterns. Electrochim Acta 44 2993-3004. 

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