Radial polymers

The final radial polymer [58] recently introduced is Kraton D-KX222C, rep-... 

Another example of an alternative rubber system is the asymmetric radial polymer (ARPS). ARPS has four equal arms of polybutadiene, with a polystyrene segment attached to one of the polybutadiene arms. A HIPS product made with ARPS blends polybutadiene produces two separate rubber phases with different morphologies and particle size distributions. The ARPS produces a capsular morphology and the polybutadiene produces a normal cellular morphology surrounded by a lamellar structure that provides a reactor product with both high gloss and high impact. 

Many industrial free-radical polymerization processes have been developed and commercialized for a variety of monomer and polymer types. A variety of monomers and polymerization processes have been commercially exploited. Further, there have been significant developments in synthesizing polymers with controlled architectures using free-radical polymerization during the last two decades. Materials synthesized include block copolymers, graft copolymers, and radial polymers. These materials find use in many common industrial and household applications such as adhesives, paints and coatings, textiles, nonwoven fabrics, personal care products, wallpaper, construction materials, specialty additives, and many other areas. 

The ability of these methods in delivering block copolymer structures has been well demonstrated. The ATRP, RAFT, and SFRP methods could all be used to make diblock and triblock copolymers, as well as radial polymers using multiarm initiators. Because these methods are based on free-radical polymerization, they give access to a wider variety of monomer systems than are currently available through non-free-radical polymerization based techniques. They can also lead to controlled polymerization under more industrially practicable conditions as compared to ionic polymerization. 

Fig. 10 Radial polymer volume fraction profiles r) for three values of the difference between pH and pXai -1, 0 and 1 under theta-conditions N = 4000 p = 20, = 10 . (a) Double...

Radial polymers may also be produced by taking advantage of the fact that butyl lithium-initiated polymerizations are termination-free and that chain ends remain active. These may be coupled with polyfunctional agents such as divinyl benzene or methyl trichlorsilane to give the radial or star-shaped polymers. Being more compact the polymers have lower melt and solution viscosities than linear polymers of equivalent molecular weight. 

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