Opaque Blends

Injection molded test specimens. PP = Marlex polypropylene homopolymer (nominal 5 melt flow). 

Property 100% KR03 90°/. KR03 10% HIPS 80% KR03 20% HIPS 70% KR03 30% HIPS 60% KR03 40% HIPS 50% KR03 50% HIPS 30% KR03 70% HIPS 100% HIPS 

Unnotched No break No break No break No break No break No break No break 24.2 

SBC blends have been evaluated with other polymer systems, including PPO, polycarbonate, PVC, PETG and PET. Although these have been the subjects of patents and have resulted in some small commercial applications, wide-scale commercial success has eluded these blends. 

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The significant growth of SBC is the direct result of its remarkable versatility. The unique combination of high transparency, good economics and outstanding impact resistance of SBC are a starting point for many clear applications. On top of that, its ability to be used on most types of processing equipment with only minor modifications makes it easy to run at most converters. When SBC themselves may not be the optimum choice for an application, their demonstrated ability to be modified in polymer blends offers additional options. The ability to be blended in both clear and opaque blends allows the manufacturer to optimize both performance characteristics and polymer cost. 

Color or opacity by automatic optical scanners with CCD electronic cameras for reflected light (viz. ColorMaster and ScanMaster). The devices are used for separating green from namral PET bottles, or opaque (blended) PE bottles from transparent. 

In August 2007 GE Plastics became SABIC Innovative, resulting in further developments in HTP technology. It was found, for example, that Extern is miscible with PI, PAI, PEI, PEEK or LCP. - For example, its blends with PEI Ultem show a smooth increase of Tg from about 220 to 311°C following the Fox equation for miscible blends. These transparent or opaque blends may be custom-colored they show an enhanced combination of performances at T< 311°C including inherent flame-retardancy, wear resistance, electrostatic dissipative properties, dimensional stability, etc. TPI blends with PEEK are available as the Victrex -MAX series. ... 

Foaming polystyrene resin prepared by blending with gas deHvers an opaque, low density sheet useful for beverage-bottle and plastic can labels as a water-resistant paper substitute (see Styrene polymers). 

In general, the multiphasic heterogenous nature of the impact grade styrene-based polymers is the root cause of their opaque-turbid nature. In determining the transparency of the blends, size and the size-distribution pattern of the dispersed phase along with the refractive index difference between the continuous and the dispersed phases are two very important criterion [133]. 

When investigating opaque or transparent samples, where the laser light can penetrate the surface and be scattered into deeper regions, Raman light from these deeper zones also contributes to the collected signal and is of particular relevance with non-homogeneous samples, e.g., multilayer systems or blends. The above equation is only valid, if the beam is focused on the sample surface. Different considerations apply to confocal Raman spectroscopy, which is a very useful technique to probe (depth profile) samples below their surface. This nondestructive method is appropriate for studies on thin layers, inclusions and impurities buried within a matrix, and will be discussed below. 

For a firm resilient opaque gel (water content 46%, 0.1 mol% of cross-linking) of a blend-type copolymer consisting of NVP and MMA (1 1 in... 

Note that sample 3, the physical blend, is completely opaque, while the OBC samples have differing degrees of clarity. These differences can be explained by examining the distribution of crystallinity in the sample. 

By virtue of its high specific gravity, barite (barium sulfate)-filled PBT grades can be used to produce very dense, X-ray opaque, ceramic-like parts [37], Recently, metal-filled PBT resins using copper or tungsten powder have been used to prepare blends with very high specific gravity. 

A good design should match a market opportunity with one or more potential technological solutions that can be investigated and explored. Eor instance, in the case of a clear Tupperware box, what plastic materials are currently in use, and what other plastic materials available are transparent. What are the reasons that some plastics are transparent and some are opaque, and what is the role of the molecular structure and what is the role of blending and additives Can we modify the current material to make it transparent, and yet retain the other desired properties (what are they) Can we find a different material that would do a better job ... 

The influence of the solvent can be observed, for example, with a PS/PC-blend CH2CI2 allows a faster evaporation and leads to the expected turbid film consisting of the amorphous components PS and PC. Instead,THF and CHCI3 evaporate slower and, hence, allow the PC to partially crystallize, which results In an opaque film. 

However, even at relatively low SAN levels, the blends can become hazy or opaque. Transparent compositions can be obtained by using a poly(siloxane)/PC copolymer instead of pure PC (25). Thin-walled articles can be successfully fabricated from such a composition. The SAN should not contain more than 25% of AN. 

Polyethylene is translucent to opaque white in thick sections, opacity increasing with density. Relatively clear film can be extruded from polyethylene, especially if it is quenched rapidly. The plastic accepts pigmentation readily. Most coloring is performed using dry-blend techniques. Color dispersion devices are required to ensure thorough mixing of resin and pigment. 

Where the two phases are completely compatible, a homogeneous polyblend results which behaves like a plasticized resin (one phase). If two polymers are compatible, the mixture is transparent rather than opaque. If the two phases are incompatible, the product is usually opaque and rather friable. When the two phases are partially compatibilized at their interfaces, the polyblend system may then assume a hard, impact-resistant character. However, incompatible or partially compatible mixtures may be transparent if the individual components are transparent and if both components have nearly the same refractive indices. Furthermore, if the particle size of the dispersed phase is much less than the wavelength of visible light (requiring a particle size of 0.1/a or less), the blends may be transparent. 

Films of starch-EAA blends were prepared by either casting aqueous dispersions or by dry fluxing both the polymers.133 Cast films were relatively transparent, flexible and stable on immersion in water. In contrast, the dry blended materials were opaque at starch levels greater than 30% and had poorer tensile properties at high starch contents. No plasticizers were needed to prepare flexible films. Starch-EAA films have also been prepared by extrusion.134... 

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