Transparent MBS

Other products having properties similar to those of the transparent ABS, transparent HIPS, transparent MBS, etc., can be included. Since such similar products have the properties and qualities similar to those of the transparent ABS, the names used may be the same, but the manufacturing methods and compositions differ somewhat. 

As can be seen from Table 6.12, the transparent ABS uses polybutadiene rubber, whereas transparent HIPS or transparent MBS uses poly(stjn-ene-butadiene) copolymer. Although such a difference in the rubber used does not bave a great influence on properties, it creates a difference in the refractive index, which in turn creates a difference in the composition of the shell. The refractive index of poly(stjn-ene-butadiene)... 

Terpolymers based on methyl methacrylate, butadiene and styrene (MBS) have been increasingly used in recent years both as tough transparent plastics materials in themselves and as additives for PVC (see also Chapters 12 and 16). 

Blending of ABS with an acrylic material such as poly(methyl methacrylate) can in some cases allow a matching of the refractive indices of the rubbery and glassy phases and providing that there is a low level of contaminating material such as soap and an absence of insoluble additives a reasonable transparent ABS-type polymer may be obtained. More sophisticated are the complex terpolymers and blends of the MBS type considered below. Seldom used on their own, they are primarily of use as impact modifiers for unplasticised PVC. 

The transparent polyamides have increased significantly in importance in recent years. For transparent applications they are competitive with poly(methyl methacrylate), polycarbonates, polysulphones and MBS. In terms of toughness they are like polycarbonates, polysulphones and MBS and much better than the... 

Where transparency is required, a range of polymers is available. Polystyrene is the least expensive but polymethylmethacrylate has an outstanding high light transmission combined with excellent weathering properties. Also to be considered are the polycarbonates, glass-clear polyamides, SAN, butadiene-styrene block copolymers, MBS polymers, plasticised PVC, ionomers and cellulose esters such as cellulose acetate. 

Methacrylate-butadiene-styrene polymers (MBS) and related materials chemically similar to ABS but often available in transparent form. 

VC/Polyepichlorohydrin and VC/Poly(epichlorohydrin-co-ethylene oxide) Graft Copolymers. Alloys of PVC and graft copolymers of this type with high backbone-polymer content give interesting results in the field of bottle blowing (12). The combination of transparency and impact strength that can be realized with these compositions should enable them to penetrate into the field covered at present by PVC-MBS mixtures. 

Additive for liquid and powder coating formulations (less brittle, self-levelling, high/low T stability, scratch and mb resistance, transparency, sur ce effects above)... 

Polyvinylchloride is rigid, transparent and, although it lacks the sparkle of poly styrene, is less brittle. Drop strength can be improved by the use of an impact modifier such as vinyl acetate or methyl methacrylate butadiene styrene (MBS). PVC is moderately permeable to moisture but has excellent resistance to oil and oxygen permeation. Plasticised PVC has high flexibility and is particularly useful when a collapsible pack is required. It is a poor barrier to moisture and a moderate barrier to gases, hence is usually overwrapped . 

MBS with controlled size of the elastomeric particles transparent Copolymer of vinylchloride, alkyl acrylate, and vinyhdene chloride Butadiene-styrene-methylacrylate-ethylacrylate Core-shell crosslinked ABS with grafted onto it PMMA shell PB-grafted with MM A, styrene and vinyl acetate Poly(butadiene-co-butyl acrylate-co-styrene)... 

Polycarbonates are polyesters of polyhydric phenols and carboxylic acid. Except for the lack of crystallinity, their properties resemble those of PEST. The most common polycarbonate, that of bisphenol-A (PC), was commercialized in 1956. PC is tough, transparent, self-extinguished, dimensionally stable, resistant to salts and oxidation, but susceptible to abrasion, stress cracking and attacks by solvent, acids and alkali. Its T = 149°C, but the ductile-brittle transition is at 0-10°C. The resin ought to be toughened, for example by addition of ABS, MBA or MBS. The annual consumption and its growth rate of PC are, respectively, 700 kton and 5%. About 40 % of PC is used in blends. 

Predesigned particles of impact modifiers are based on core-shell technology. Core is involved in impact modification and shell improves adhesion between PVC and impact modifier particles.Three major combinations are used methacrylate-butadiene-styrene, MBS, which has a core made out of butadiene-styrene copolymers and shell made out of methylmethacrylate-styrene copolymer, acrylic impact modifiers, AIM, which have a core made out of acrylic and shell from polymethylmethacrylate, and silicone-acrylic have multilayer structures with silicone-acrylic in the core. MBS has excellent compatibility with PVC, similar to ABS, which is used as an impact modifier of PVC, as well. In both cases of ABS and MBS, weather resistance is lacking, therefore they are used for indoor applications only. At the same time, MBS gives translucent to crystal clear products, whereas with AIM, only translucent products are possible. In order to improve optical properties of AIM, it has to be reformulated. For transparent products, the core is made out of acrylic-styrene copolymers. Comparing silicone and all acrylic impact modifiers, PVC containing silicone-based products has superior low temperature impact properties. The incorporation of silicone into an acrylic impact modifier provides excellent weatherability, and thermal stability. It has shown improved retention of impact after outdoor weathering in PVC. ... 

Ramavath P, Biswas P, Rajeswari K, Suresh MB, Johnson R, Padmanabham G et al (2014) Optical and mechanical properties of compaction and slip cast processed transparent polycrystalline spinel ceramics. Ceram Int 40 5575-5581... 

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