The impact of replacing three polyether polyols with different levels of a single palm olein‐based natural oil polyol (NOP) was systematically correlated with the changes in foaming reactivity, cell structure, physico‐mechanical properties, and morphology of viscoelastic (VE) foams. The data show that replacing the polyether polyols with the NOP slightly increased the rate of the foaming reactivity. Increasing the NOP content resulted in increased cell size and cells remained fully open. Increased NOP content contributed to higher load bearing properties of VE foam, which can be attributed to higher functionality of NOP compared to polyether polyols. Addition of the NOP slightly increased the resilience of the foams, however, the hysteresis which is the measure of energy absorption remained mostly unaffected. Age properties, characterized by dry and humid compression sets, were mostly unaffected by the replacement of the polyether polyol with the NOP. The addition of NOP did not impact the morphology of the VE foam polymer matrix, which appears to retain a low degree of hard and soft segment domain separation. Overall, the results demonstrate a feasibility that the NOP can be used to partially replace the polyether polyols in VE polyurethane foams without significant impact on the functional performance.

Waterborne polyurethane dispersions (WPUDs) containing a renewable palm oil‐based 9,10‐dihydroxystearic acid (DHSA) as an isocyanate‐reactive compound bearing ionizable carboxylic group to incorporate hydrophilic groups into the polymer chain have been successfully prepared. The WPUDs were prepared by using polyether and polyester polyols of 2000 molecular weight, DHSA and its traditional petroleum‐based counterpart 2,2‐bis(hydroxymethyl)‐propionic acid (DMPA), and an aliphatic diisocyanate (isophorone diisocyanate, IPDI). A comparison was made between the properties of WPUDs obtained using blends of DHSA and DMPA at different molar ratios and a reference WPUD based on DMPA. The particle size of polyester type WPUDs containing DHSA was reduced at a 0.5 to 0.5 molar ratio of DMPA to DHSA. A lower initial temperature was used in the preparation of NCO‐prepolymers with DHSA as compared to DMPA and this eased the preparation of WPUDs. The effect of molar ratio of DMPA to DHSA on the properties of films and coatings prepared with WPUDs was evaluated. The best properties were obtained with WPUDs prepared with a 0.5 to 0.5 molar ratio of DMPA to DHSA. The incorporation of renewable palm oil‐based DHSA into WPUDs improved water resistance (lower water uptake) and exhibited good combination of properties including hardness, adhesion strength, tensile strength, and elasticity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43614.

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The performance comparison between two controllers, namely Adaptive Neuro-Controller (ANC), based on Multi Layered Perceptron (MLP) network and Adaptive Parametric Black Box Controller (APBBC) are presented in this paper. The comparison is based on the capability of the controlled output tracking the model reference output and the percentage of overshoot. Both controllers are based on a black box approach that offers simpler design approach. The Model Reference Adaptive System (MRAS) has been used to generate the desired output path and to ensure the output of the controlled system follows the output of the reference model. Recursive Least Square (WRLS) algorithm will be used to adjust the controller parameters to minimize the error between the plant output and the model reference output. The controllers have been tested using a linear plant and a nonlinear plant with several varying operating conditions. The simulation results show that output response of ANC have slightly better tracking performance compared to APBB controller for linear plant and have equivalent performance for nonlinear plant.

In this paper, an intelligence controller namely Adaptive Neuro-controller (ANC) based on Hybrid Multilayered Perceptron (HMLP) network is developed for the attitude control of a nano-satellite. The objective of this paper is to compare the tracking performance between ANC based on HMLP network and ANC based on standard MLP network for controlling a satellite attitude. Both ANC's use Model Reference Adaptive Control (MRAC) as a control scheme. The control scheme was used to control a time varying systems where the performance specifications are given in terms of a reference model. Weighted Recursive Least Square (WRLS) algorithm has been used to adjust the controller parameters to minimize the error between the actual output and the reference input. Y-Thompson spin control is adapted to the satellite system as the reference input throughout the simulation. These controllers have been tested using Innovative Satellite (InnoSAT) plant with some variations in operating conditions such as varying gain, noise and disturbance. The simulation results indicated that ANC based on HMLP network is adequate to control satellite attitude and gave better result than the ANC based on MLP network.