Abstract.Standard maize (SMS) and waxy maize starch (WMS) were hydrothermally treated at their residual moisture level (~12 %) by Instantaneous Controlled Pressure Drop process in order to obtain pre-gelatinised starches in a single step. The effect of two parameters of this process, namely the steam pressure level and processing time, on the structural and rheological properties of the native maize starches were described. The occurrence of partial gelatinization for DIC treated starches was clearly attested by the increase of the median volume diameter in cold water, the decrease of the gelatinization enthalpy and a loss of birefringence under polarized light, this was more prominent for the highest pressure and longest time: 2.7 to 3 bar for 200 to 300 seconds.Sensitivity of starches to the process was also dependent on their origin, SMS being more affected than WMS.

Improving the processability while maintaining excellent stretch and elasticity is very important for elastomeric materials. Here is discussed the processing and properties of several recently developed elastomers, and it is shown that optimum elastic recovery can be achieved by blending polyolefin elastomers with fully hydrogenated styrenic block copolymers, the Figure showing a co‐continuous morphology.

A flow-injection polymer analysis (FIPA) method for the dilute solution characterization of unsaturated styrenic block copolymers was developed. The method is rapid, works with both butadiene and isoprene comonomers, and covers a range of 0 -100% styrene content in the polymer. Solutions of the polymer were introduced into a flowing mobile phase and monitored by an array of three close-coupled detectors: a right-angle laser light-scattering unit, a differential refractive index detector (DRI), and a differential pressure viscometer. In addition, a separate, dual-detector instrument was set up specifically to evaluate the styrene content by the FIPA method. In that case, the detectors were a DRI and an ultraviolet detector. Within an analysis time of a few minutes, information on molecular weight, molecular size, and comonomer composition could be obtained directly. The data were compared to those obtained from a preexisting gel permeation chromatography analysis method.

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