Segmented elastomers

Trade name Manufacturer Hard segment Elastomer segment Notes... 

Step polymerization is used to synthesize multiblock copolymeric elastomers (referred to as segmented elastomers). An example is the polyester-polyurethane system produced by the reaction of a diisocyanate with a mixture of macro diol and smallsized diol (Eq. 14). The macro diol (usually referred to as a... 

Yilgor I, Yilgor E, Eberle J, Steckle W Jr, Johnson BC, Tyagi D, Wilkes GL, McGrath JE (1983) Novel segmented elastomers from amino alkyl-terminated dimethylsiloxane oligomers Polymer Preprints 24(1) 167... 

The first group are the semicrystalline homopolymers, while a second group would include a diverse collection of block polymers, blends, and segmented elastomers. The latter systems were emphasized at a symposium on "Multicomponent Polymer Systems organized as part of the 175th National Meeting of the American Chemical Society in Anaheim, March 13-17, 1978. 

Synthesis of Poly(ether urethane amide) Segmented Elastomers... 

Prepolymers of polybutadiene diol (M. 2500), polytetramethylene oxide diol (M. 1400 and M. 2100), and prepolymer of polypropylene oxide diol (M. 1400) were used to obtain segmented elastomers SPU-1 to SPU-5. Prepolymers were prepared by reaction of appropriate diol with 2,4-toluene diisocyanate (2 moles per one mole of diol). Prepolymers of polytetramethylene oxide diol (elastomers SPU-1 and SPU-4) were cured by methylene-bis-o-chloroaniline, MOCA, or by mixture of MOCA and polytetramethylene oxide diol (SPU-2 and SPU-3). SPU-5 samples, prepared from prepolymer of polypropylene oxide diol, were cured by MOCA, and prepolymer of polybutadiene diol was cured by a mixture of MOCA and polytetramethylene oxide diol (SPU-6). Various concentrations of hard segments, Cj, in SPU were set by a ratio of mixture components and molecular weight of prepolymer (Table 10.14). Excess of NCO-groups was in the range 1.03-1.06 for SPU-1 to SPU-5 and 0.99 for SPU-6. All samples were cured at 80°C for 4 days. The... 

Over the past twenty years or more there has been widespread interest in various kinds of multicomponent polymer systems, including polyblends, block copolymers, and segmented elastomers. 

Microcellular foams (elastomers) differ from classical foams, because of their cell structure, higher density of the foams, which is typically 200 kg/m, and the structure of the matrix. Microcellular foams are foamed segmented elastomers with smaller number of round cells, unlike polygonal cells with ribs in standard foams. Because of their superior mechanical properties they are used for shoe soles, car bumpers, etc. They are formed by adding water and excess isocyanate in the elastomer formulation, which liberates CO2. 

TPUs are segmented elastomers with strong physical crosslinks. Polymerization is completed in the manufacturer s plant and the user buys the granulated resin. 

Sauer B B, McLean R S, Brill D J and Londono D J (2002) Morphology and Orientation during the Deformation of Segmented Elastomers Studied with Small-Augle X-ray Scattering and Atomic Force Microscopy, J Polym Sci Part B Polym Phys 40 1727-1740. 

Bonart R. (1968) X ray investigations concerning the physical structure of crosslinking in segmented elastomers. J Macromol Sci Phys B2 115. 

Sauer B B, McLean R S and Brill D J Londono J D (2001) Morphology and orientation during deformation of segmented elastomers studied by SAXS and atomic force microscopy, Abstr 222 ACS Meet, Chicago III, USA, PMSE-163. 

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