Thermal characterization and morphological study of polyphenylene sulfide-polycarbonate blends

A Review of Polylactic Acid as a Replacement Material for Single-Use Laboratory Components

Every year, the EU emits 13.4 Mt of CO₂ solely from plastic production, with 99% of all plastics being produced from fossil fuel sources, while those that are produced from renewable sources use food products as feedstocks. In 2019, 29 Mt of plastic waste was collected in Europe. It is estimated that 32% was recycled, 43% was incinerated and 25% was sent to landfill. It has been estimated that life-sciences (biology, medicine, etc.) alone create plastic waste of approximately 5.5 Mt/yr, the majority being disposed of by incineration. The vast majority of this plastic waste is made from fossil fuel sources, though there is a growing interest in the possible use of bioplastics as a viable alternative for single-use lab consumables, such as petri dishes, pipette tips, etc. However, to-date only limited bioplastic replacement examples exist. In this review, common polymers used for labware are discussed, along with examining the possibility of replacing these materials with bioplastics, specifically polylactic acid (PLA). The material properties of PLA are described, along with possible functional improvements dure to additives. Finally, the standards and benchmarks needed for assessing bioplastics produced for labware components are reviewed.

The fabrication and neutron shielding property of polyphenylene sulfide containing salicylic acid/Gd2O3 composites

A series of neutron absorbing materials with good neutron absorbing capacity, high strength and good thermal property were designed and prepared in this work. First of all, polyphenylene sulfide containing different mole content of salicylic acid (SAPPS) in the main chain was synthesized by nucleophilic substitution polymerization under high pressure. Then the composites with different content of nano Gd2O3 and modified PPS were prepared by melt blending method. The testing results indicated that the copolymers SAPPS were synthesized successfully, there was an interface interaction between nano Gd2O3 and the matrix without the need for surfactants or coupling agents. Additionally, the content of nano Gd2O3 had no obvious influence on the thermal property of the composites. While following with the increase of the content of nano Gd2O3, the tensile strength of the composites increased firstly and then decreased, when the content of nano Gd2O3 was 10 wt%, the tensile strength of 10%Gd2O3/5%SAPPS reached the maximum value of 74.9 MPa. The results of neutron shielding testing indicated that the content of nano-particles had a large effect on the neutron shielding rate of composites. The neutron shielding rate of 50%Gd2O3/5%SAPPS composite was up to 83%. All of these results indicated that the Gd2O3/5%SAPPS had potential to be applied to the high-temperature resistance and thermal shielding materials in nuclear and aerospace applications.

Synthesis and characterization of silane-grafted polyphenylene sulfide

A novel polyphenylene sulfide (PPS) modified by silane grafting and water cross-linking technology has been prepared using suspension grafting. Fourier transform infrared and x-ray photoelectron spectroscopic spectra demonstrated the achievement of silane grafting and subsequent water cross-linking. The grafting degree could be adjusted by altering the silane/PPS molar ratio, reaction temperature, reaction time, and so on. Wide angle x-ray diffraction analysis showed that the crystallinity and crystal size of the modified PPS decreased with increase in the grafting degree. Differential scanning calorimeter results also confirmed that the crystallinity and crystallization temperature decreased with the increase in the grafting degree. The silane-grafted PPS exhibited two weight loss stages in thermogravimetric curves, and the initial thermal decomposition temperature was much higher than the processing temperature. Therefore, the silane-grafted PPS is thermally stable enough to be used as a high-performance polymer and polymer matrix for structural applications. The extent of silane grafting plays a key role in the improvement of the impact toughness of the silane-grafted PPS. With the increasing silane grafting degree, the impact strength of the silane-grafted PPS/neat PPS blends obviously increased.

Heat distortion temperature of PPS/PC blend, PPS/PC nanocomposite and PPS/PC/GF hybrid nanocomposite

The polyphenylene sulfide (PPS) blended with polycarbonate (PC), reinforced glass fiber (GF) and nanometer calcium carbonate (nano-CaCO3) filled PPS ternary composite, as well as the PPS/PC/GF/nano-CaCO3 hybrid composite, were prepared by means of a twin-screw extruder, and the heat distortion temperature (Td) of these materials was measured to identify the influence of the PC and nano-CaCO3 content on the heatproof properties. The Td values for the PPS/PC blend were lower than that of the neat PPS, when the PC weight fraction (φPC) was less than 20%, and increased with increase in φPC. The Td values for the PPS/GF/nano-CaCO3 ternary composite, on which the particle surface was treated with a titanate coupler, were higher than that of the composite with the particle surface treated with a stearate coupler. When the nano-CaCO3 weight fraction (φf) was less than 6%, the Td values for the PPS/PC/GF/nano-CaCO3 hybrid composites increased with increasing φf; at greater than the maximum of 6%, Td decreased. There was a certain synergistic effect of the GF and nano-CaCO3 on the heatproof properties in the PPS/PC composite.