Iron polymers, network structures

In a uniform magnetic field, the iron particles interact with each other, but the particles do not interact with the polymer network. The polymer network can immobilize the ordered structure, but it cannot prevent the break-up of the ordered structure under compression. The iron particles in the chains slip out from the columnar structure, breaking the ordered structure and resulting in hysteresis, as shown in Fig. 15. 

Fig. 24 Dependence of the magnetic field intensity on the elastic modulus. The arrangements of the particles in the polymer networks are parallel to the applied mechanical stress while the applied uniform magnetic field is parallel (a) or perpendicular (b) to the columnar structure. The concentration of the carbonyl iron particles in the mPDMS matrix is indicated...

The chelation leads to a pseudocyclization whereby a coordination network is formed. The structure shown in Equation (28-49) is therefore only one of many possibilities. According to the nature of the metal ion and the molar ratio of metal/PTO, the color varies between yellow (Zr /PTO = 0.35) through orange (Zn /PTO=2) and olive green (Cu /PTO = 0.66) to brown (Ca /PTO = 1) and black (Fe /PTO = 1). White and blue shades are not obtained. The chelated polymers are very flame resistant, especially when chelated with zinc, tin, or iron ions. Mercury ions produce radiation-proof but not fire-proof polymers. 

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