The Influence of Nano CaCO3 on Nucleation and Interface of PP Nano Composite: Matrix Processability and Impact Resistance

Polypropylene (PP) is a commodity material that has been increasingly used in different industries in the past two decades due to its versatile properties when enhanced with additives. Homo polypropylene, in general, has weak mechanical properties and limited chemical resistance; thus, using a different type of fillers to adjust such properties to fit the required applications opened a large market for this commodity. Understanding the interface constituent between the polymer matrix and the added filler and the nucleation behavior is a key to fine control of the enhancement of PP properties. In this study, PP was incorporated with nano calcium carbonate (CaCO3) at 2 and 5 wt% in the presence of maleic anhydride (MAH) to overcome the weak interface due to low polymer polarity. The mix was compounded in a twin screws extruder at a temperature range of 180–200 °C ; then, the prepared samples were left to dry for 24 h at 25 °C. Nuclear Magnetic Resonance (NMR) was used to study the interface adhesion of the nanofiller and the curved revealed that at 2% of nano CaCO3 PP structure remained the same and the nano experienced good adhesion to the polymer matrix. The mechanical impact resistance results showed a real enhancement to the polymer matrix of the nanocomposite by 37%. Moreover, DSC results showed a faster crystallinity rate due to the nanofiller acting as a nucleating agent and rheology tests indicated that low content of nano additive (2%) has better processability behavior, with suitable viscosity complex values at high frequencies.

Propellers and Shafting for Sustainable Shipping

The importance of the line shafting, tailshaft, propeller, and thrust shaft cannot be over-emphasised. Failure of any one of them will rend the ship inoperable with possible disastrous consequences. Single line shafting is used on the majority of ships, but not in passenger ships and on short voyage ro-ro services where twin screws are employed. Propellers, because they are outside the ship, are often neglected and are usually only inspected when the ship is in drydock. More frequent examination can be undertaken when a ship is alongside and the shafting is being rotated with the turning gear. Damage to the propeller blade can lead to vibrations being set up in the line shafting causing overheating of the shafting bearings, main thrust, etc. The selection of shafting and propeller materials is usually within manufacturers’ specifications and complies with the various classification society requirements as well as the statutory requirements of governments.

Simulation of the Mixing in a Novel Fully Wiped Co-Rotating Non-Twin Screws

This work aims at simulation of the mixing performance in the novel co-rotating non-twin screw group developed by the authors. The simulation concerns the incompressible fluid obeying Carreau flow model. Using the mesh superposition technique, the mixing performance in such novel mixing sections, as well as in the conventional twin screw groups with one and two tips, are simulated. Adopting the particle tracking technique, distributive mixing is visualized by the evolution of the mixing of a cluster of particles in addition to using the segregation scale. Dispersive mixing is evaluated using mixing index in combination with the probability distributions of cumulative mixing index. The computational results reveal that the novel screw group is superior in mixing ability.

The Studying on the Influence of Coupling Agents to Short Glass Fiber Reinforced Polyamide Composites

Influence of coupling agents on microstructure and mechanical properties of short glass fiber reinforced PA66 composites(SGF/PA66) were investigated by using twin screws extruder and injection machine in this paper. When coupling agents (A1100 or A1100+A+B) were added, short glass fiber was distributed in the PA66 matrix more homogeneously; at the same time, the microstructure and properties of GF/PA66 were improved too. Modified effect of multiple coupling agent (A1100+A+B) is better than that of only A1100 and the desired content of A1100 is about 1.5~2.0wt%. When glass fiber content was less than the critical value (35~40%), mechanical properties of PA composites increase with fiber content increasing, but it begin to decrease when content was excess that value. At last, Failure mechanism of GF/PA66 (treated by A1100 or A1100+A+B) was obtained: adhesion of interface between glass fiber and PA66 matrix, friction after the adhesion, glass fiber pullouted and matrix failure.

Properties of HDPE/UHMWPE Blown Films

HDPE and UHMWPE were blended in the twin screws extruder with two kinds of screws scheme and the HDPE/UHMWPE films were prepared in the blown film extruder. The mechanical properties, rheological property and crystallization behavior of the blends were discussed. The results showed that UHMWPE could improve the mechanical properties of HDPE film, but made the melt torque of the blends increase. The surface morphology and crystallization behavior of the blends were observed by polarized light microscope. It was found that the dispersion and molten degree of UHMWPE in the blends made by the screws scheme B were improved greatly.

Effect of Processing Method on Conductivity and Mechanical Properties of Glass Fibre Reinforced Carbon Black Filled Polyethylene

The conductivity and mechanical properties of carbon black (CB) filled polyethylene (PE) composites depend on the conductive filler, molecular structure of polymer matrix, and the processing methods which are applied. CB filled high density polyethylene without and with glass fibre (GF) composites have been manufactured using single and twin screws extruder. The composite made from the single screw extruder showed a much higher conductivity than that made from twin screws extruder for CB/PE composites with and without glass fibre. The conductive paths are formed at very low CB content (1wt% CB for GF/CB/PE) when using single screw extruder to manufacture. The microstructure of these composites were analysed using SEM.