Production of Composite Fibers from Natural Rubber and Lignin

The interest of natural rubber (NR) product applications have been increased as natural rubber can be obtained from nature and it can be produce into sustainable products. It’s widely used in applications such as tires, wires, latex products, medical devices, and sport components. In this work, the use of electrospinning technique to produce fibers has been carried out because this technique has been proved to be a simple and effective technique for fiber production. This work aimed to study morphology, diameter, and functional group of natural rubber fibers, DPNR fibers, and different loadings of lignin in DPNR/lignin composite fibers produced by electrospinning technique. The condition for electrospun fibers were as following; needle-target distances of 15 cm and flow rate of 2.5 ml/h. The results of deproteinization by urea, SDS solution, and acetone showed protein in NR latex decreased. Moreover, increasing load of lignin resulted in an increase of the diameter of DPNR/lignin composite due to increasing of viscosity of the solution related to increasing of viscoelastic force. Characterizations of these fibers were reported using scanning electron microscopy to examine fibers surface and measure diameter of the fibers. Fourier transform infrared spectroscopy was used to examine the functional group of the fibers

Heat Integrated Process Design, Simulation and Control of Polymerization and Drying Sections for HDPE Production

This paper describes a production model for high density polyethylene. Aspen Polymer Plus was used to model and simulate the polymerization drying and separation sections. Heat operations were improved using Aspen Energy Analyzer; The pinch analysis method generated, the heat exchanger network. The dynamic model via Aspen Plus Dynamics evaluated the stability and controllability of the models. The simulation results such as production rate, polydispersity index, weight-average molecular weight, and number-average molecular weight correponded with Hakim and Moballegh [1]. Five heat exchanger networks were proposed: the one with the lowest total index cost was selected to perform the dynamics analysis

Control of Ethylene Dichloride Cracking Furnace Using an Analytical Model Predictive Control Strategy for a Coupled Partial Differential Equation/Ordinary Differential Equation System

A nonlinear optimization-based control system with analytical model predictive control (AMPC) structure is formulated in cascade with an off-line pseudo-steady-state calculator for an ethylene dichloride (EDC) cracking furnace process described by a coupled partial differential equation/ordinary differential equation model. The objective of the proposed control system is to control the EDC cracking rate at the desired set points by manipulating the fuel gas flow rate with constraints to avoid extensive coke formation. To handle the complex behaviors that are affected by radiating walls interacting with spatial dynamics of the reactor coil, the set point calculator is employed to provide an optimal target for the constrained optimization-based controller in calculating the control actions. Simulation results show that the proposed control system is successful to regulate the controlled output at the desired set points. Control performance tests with servo and regulatory problems demonstrate that the developed control system is capable of providing excellent responses to achieve the desired set point and reject process disturbance

Film and latex forms of silica-reinforced natural rubber composite vulcanized using electron beam irradiation

A thorough study was undertaken of the synthesis of natural rubber-silica treated with bis-(3-triethoxysilylpropyl) tetrasulfane (NR/TSi) vulcanized using electron beam irradiation (EB) and sulfur by varying the EB dose. The surface treatment of silica was confirmed using Fourier-transform infrared spectroscopy and scanning electron microscopy images. Composites were cast and vulcanized in film and latex forms compared with sulfur vulcanization. Investigation covered the mechanical properties, thermal stability, swelling resistance, and degradation under heat and humidity testing of the NR/TSi composites. It was found that the TSi had great dispersal in the NR matrix. TSi in NR matrix had a positive effect on mechanical properties, swelling in water and toluene, and thermal stability. Increasing the radiation intensity up to 250 kGy led to superior mechanical properties but for further increase in the radiation intensity, the tensile strength dropped. Degradation under thermal and humidity testing showed that the un-vulcanized composite had higher physical degradation than the vulcanized samples. Therefore, NR/TSi vulcanized using 200 kGy EB vulcanized in latex form had the greatest mechanical properties for various applications without producing any residual vulcanizing agent