Copolymer in blend

The use of small amounts (0.5-3%) of polyethylene-polydimethylsiloxane or polystyrene-polydimethylsiloxane block copolymers in blends with a host... 

Xe NMR of Ethylene/Propylene Copolymers in Blends and Block-copolymers with Polypropylene... 

Another approach to improving the properties of starch-filled polyolefin materials involves the use of ethylene-acrylate copolymers in blends with PE.45 Addition of copolymers of ethylene with methyl acrylate, ethyl acrylate or butyl acrylate were shown to improve the properties of PE films, allowing for higher starch contents. Coextrusion of starch-containing films with outer layers incorporating oxidative pro-degradants has also been utilized 46 The inner layer can contain up to 40% starch the... 

Use of statistical copolymers in blends is usually predicated on the existence of a specific interaction between one of the comonomers in the copolymer and other ingredients in the mixture. Thus PVC is miscible with the ethyicne/ethyl acrylate/carbon monoxide copolymers [28]. The homogenizing effect here is a weak acid-base interaction between the carbonyl of the copolymer and the weakly... 

The major cunent applications of block copolymers in blends involve styrene-diene polymers, but other block polymers are also useful. Siloxane-alkylene ether block copolymers are widely used as surfactants in the manufacture of polyurethane foams, for example. 

The photophysics of jt-conjugated polymers are reviewed in detail in other chapters of this book. (See, for example, Chapter 3.) Here, we focus on the electronic and photophysical phenomena that occur at the heterojunction between two different semiconductor polymers. The heteroj unctions are formed by combining four different polyfluorene copolymers in blend or bilayer thin films and are investigated using time-resolved and steady-state, temperature- and elec-tric-field-dependent photoluminescence measurements as well as electroluminescence and time-resolved spectroscopy. We review a body of work carried out in our laboratories over the last few years, and published in numerous journal articles (see refs. [13-17]). 

The influencing factors for these effects, viz., structure, composition, nature of copolymer in blends are presented in this section. 

Block copolymers In blends homopolymer/block copolymer blends... 

Identification of phases in polymers, 16 location of copolymers in blends, and identification of inorganic pigments and fillers... 

K. R. Sharma, Mathematical Modeling of Partially Miscible Copolymers in Blends, 215th ACS National Meeting, Dallas, TX, March 1998. 

D. R. Paul and J. W. Barlow, A binary interaction model for miscibility of copolymers in blends, Polymer, 25,487, 1984. 

Mixed system glass transition temperature, Tg is defined by the requirement that entropy for the glassy state is identical to that for the rubbery state [5]. A revisit of the Couchman equation without neglecting the differences of entropy of mixing in the glassy and rubbery state is used to develop a mathematical framewoilc to represent multiple glass transition tanperatures in partially miscible copolymers in blends. 

SAK Sakellariou, P., Eastmond, G.C., and Miles, I.S., Interfacial activity of graft copolymers in blends effect of homopolymer molecular weight. Polymer, 33, 4493, 1992. 

In order to form block copolymers in blends of polycondensates, it is possible to use bisepoxides that react with the end groups of the blend components. A combination of peroxide and unsaturated bifunctional components (MA, triallylisocya-nurate, low-molecular-weight unsaturated rubber) was reported to induce copolymer formation in PS/PE and polyolefins blends [157-159]. 

A binary interaction model for miscibility of copolymers in blends. 

We have previously alluded to two major commercial applications of block copolymers the addition of AB diblock copolymers in blends of homopolymers, A and B, to improve the processability and mechanical properties of the mixture, and the use of ABA-type triblock copolymers as thermoplastic elastomers when block A (e.g., PS) is below its glass transition, whereas block B (e.g., polybutadiene) is above its glass transition at ambient temperature. Other products made from block copolymers include pressure-sensitive adhesives, oil additives, and automobile parts. 

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