Blend butadiene-styrene block

More recently Fina Chemicals have introduced linear SBS materials (Finaclear) in which the butadiene is present both in block form and in a mixed butadiene-styrene block. Thus comparing typical materials with a total styrene content of about 75% by weight, the amount of rubbery segment in the total molecule is somewhat higher. As a result it is claimed that when blended with polystyrene the linear block copolymers give polymers with a higher impact strength but without loss of clarity. 

BR is incompatible with CR because of the large difference in polarity. Mingyi et al. have studied their compatibUization in the presence of a styrene-butadiene-styrene block (SBS) copolymer [30]. The blends were prepared by blending the two mbbers separately at approximately 75°C. The master batch of the BR compound contained 1 part of sulfur, 2 parts of copolymer, 1.5 parts of TMTD, 5 parts... 

Another important class of copolymers synthesized by chain polymerisation are block (or sequenced) copolymers diblock and triblock copolymers being the most important ones. They are very useful as compatibilisers (emulsifiers) in immiscible polymer blends. Another major use is as thermoplastic elastomers. Both uses are best explained through the example of butadiene-styrene block copolymers. 

Blends of butadiene-styrene block polymers with polyolefins, particularly polypropylene are mentioned in literature to improve the impact strength of the latter. Since similar improvements can be realized from the use of polyolefin block polymers, the blends have not gained much recognition. However, butadiene-styrene radial teleblock polymers are blended into polyethylene film, to increase the tear resistance and tensile impact. ... 

Super High Impact Polystyrene Based on Polystyrene and Butadiene-Styrene Block Polymer Blends... 

The resulting TPE can either be used alone or blended with aliphatic oil and polypropylene. In the former case a higher tensile strength and elongation at break are obtained in comparison with the commercially available styrene-hydrogenated butadiene-styrene block copolymers, especially at high temperatures. 

When a block copolymer is blended with a homopolymer that differs in composition from either block the usual result is a three-phase structure. Miscibility of the various components is not necessarily desirable. Thus styrene-butadiene-styrene block copolymers are recommended for blending with high density polyethylene to produce mixtures that combine the relative high melting behavior of the polyolefin with the good low temperature properties of the elastomeric midsections of the block polymers. 

A blend of PS in HDPE (interpenetrating network) is commercially sold as expandable beads (Arcel , ARGO Neopolen S, BASF) for making cellular foams [Kosoff, 1987]. Although PS and polyethylene are immiscible, closed-cell foams made from this immiscible pair appear to combine the rigidity of PS with the solvent resistance and abrasion resistance of HDPE. Hydrogenated styrene-butadiene-styrene block... 

Radioluminescence spectroscopy has been used to examine molecular motion, solubility, and morphology of heterogeneous polymer blends and block copolymers. The molecular processes involved in the origin of luminescence are described for simple blends and for complicated systems with interphases. A relatively miscible blend of polybutadiene (PBD) and poly(butadiene-co-styrene) and an immiscible blend of PBD and EPDM are examined. Selective tagging of one of the polymers with chromophores in combination with a spectral analysis of the light given off at the luminescence maxima gives quantitative information on the solubility of the blend components in each other. Finally, it is possible to substantiate the existence and to measure the volume contribution of an interphase in sty-rene-butadiene-styrene block copolymers. 

Przybytniak, G. K., Zagorski, Z. R, Zuchowska, D., Free radicals in electron beam irradiated blends of polyethylene and butadiene-styrene block copolymer. Radiation Physics and Chemistry 1999,55(5-6), 655-658. 

Blends of radial block rubbers with other polymers provide useful variations in properties. Thermoplastics such as polyethylene and polystyrene have already been mentioned. There are several polymers >diich can be added to butadiene-styrene block... 

Mixtures of PPE and PS, or styrene-butadiene-styrene block copolymers have been extruded with maleic anhydride of fumaric acid to obtain compatibi-lized blends [42], In the same way, PPE with pendant glycidyl groups can be co-extruded with a poly(olefin) having anhydride groups [28], PPE can be grafted onto poly(ethylene) by melt kneading both modified polymers in the presence of a binder such as phenylenedi-amine. Both polymers are modified with maleic anhydride. The grafting takes place in situ. Amines may enhance the improvement of certain physical properties when used in combination with various compati-bilizers [29]. 

Super-high-impact polystyrene can be made from blends of polystyrene with butadiene-styrene block copolymers. As illustrated in Figure 2.4, the morphology of rubber-containing domains is finer than the high-impact polystyrene structure shown in the upper left of Figure 2.3. The subject has been recently reviewed by Aggarwal and Marti and Riess. ... 

A series of studies of the emulsifying effect of hydrogenated butadiene/styrene block copolymer on the morphology and mechanical properties of blends of high density polyethylene with polystyrene has been presented by Fayt et al. (see also Ref. ). 

Blends with styrene-butadiene-styrene block copolymers as impact-modified molding materials W. Germany 2,713,455 1977 General Electric... 

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