Hysteresis in polymers

Characteristics and Mechanisms of Hysteresis in Polymer Field-Effect Transistors... 

Paasch G, Scheinert S, Herasimovich A, Hdrselmann I, Lindner Th (2008) Characteristics and mechanisms of hysteresis in polymer field-effect transistors. Phys Stat Sol A 205 534-548... 

She et al. [128] used rolling contact to estimate the adhesion hysteresis at polymer/oxide interfaces. By plasma oxidation of the cylinders of crosslinked PDMS, silica-like surfaces were generated which could hydrogen bond to PDMS r olecules. In contrast to unmodified surfaces, the adhesion hysteresis was shown to be larger and proportional to the molecular weight of grafted polymer on the substrate. The observed hysteresis was interpreted in terms of the orientation and relaxation of polymer chains known as Lake-Thomas effect. 

An instrument designed to follow hysteresis losses in polymers by measuring the resistance to the rolling of small balls over the surface of the test piece it can investigate transitions in polymers to as low a temperature as -120 °C. Superseded by modem dynamic mechanical thermal analysis equipment. 

Implications for Biosensor Design. This study indicates that aliphatic amine containing polymers are not appropriate for biosensing. The proposed model suggests that formation of a separate amine phase is necessary to see swelling as the pH decreases from 7 to lower values. However, the formation of a separate amine phase is also linked to slow rates of response and hysteresis in the variation of volume vs. pH when measured after equilibration for 40 minutes. 

One dominating factor for hysteresis in organic polymers is related to the pres-... 

Sulfur-vulcanizable elastomers have been prepared that are designed to reduce hysteresis in tires by reducing the number of polymer free ends. The method for this preparation entails anionically preparing poly(styrene-co-butadiene) using a lithium thioacetal initiator followed by incorporation of a vulcanization agent into the elastomer terminus. 

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