polymerguru

Today's KNOWLEDGE Share New recycling techniques aim to give colorants a second life Over the next five years, Bert Weckhuysen will investigate how colorants from plastic bottles can be recycled more effectively. In August, he received a grant from the initiative Circular Plastics NL, funded by the Dutch National Growth Fund. Weckhuysen is collaborating with Jules Roelofs from Holland Colours, a manufacturer of colour concentrates, and CuRe Technology, a plastic recycling company. Walk through any supermarket and you will see shelves lined with plastic bottles in every colour of the rainbow: green, red, blue – added to plastics to make packaging more appealing. But what happens to all those colorants once the bottle is empty and sent for recycling? At present, not much. Most colorants are lost in the recycling process as the plastic is often burned or, at best, reused. According to Bert Weckhuysen, Distinguished University Professor of Catalysis, Energy, an...

Today's KNOWLEDGE Share Novel liquid phthalonitrile monomers towards high performance resin: Phthalonitrile resins are one of the high temperature resistant polymers which can be potentially used for harsh environments in both military and domestic fields. The high melting points of the monomers led to short processing windows and made processing procedure challenging and energy intensive. To solve this problem, liquid phthalonitrile monomers containing flexible siloxane segments were designed and synthesized. The long bond length and large bond angle of Si-O-Si chain segments introduced flexibility into the monomers and effectively reduced the melting point to −35.9 °C. Meanwhile, the high bond energy preserved the thermal stability of the resulting cured resin. The high fluidity (viscosity of ∼ 2 Pa·s at 30 °C) allows the monomers to be processed at room temperature without additional heating. In addition, the monomers can be dissolved in common organic solvents, s...

Today's KNOWLEDGE Share EU regrets lack of conclusion on global plastics agreement After two years of negotiations, UN member states failed to reach an agreement. The EU regrets that the 5th session of the Intergovernmental Negotiating Committee on the Global Plastics Treaty (INC-5) finished without a deal yesterday in Busan, South Korea. After two years of negotiations and a week of talks in Busan, UN member states could not find an agreement on what would have been the first-ever global legally binding instrument to end plastic pollution. The session has now been suspended and negotiations will continue in 2025.  Speaking on the result,  Jessika Roswall , Commissioner for the Environment, Water Resilience and a Competitive Circular Economy said: “I strongly regret that there is no agreement on a new global plastics treaty. If business as usual continues, plastic production will triple by 2060. “The EU will remain firmly committed to finding a global solution. Our o...

Today's KNOWLEDGE Share PEKK (Polyetherketoneketone) vs PEEK (Polyetheretherketone): PEKK and PEEK are both in the Polyaryletherketone family of ultra-high performance polymers.  Unlike PEEK, PEKK is a copolymer with a slower and highly tunable crystallization rate making it the preferred choice for additive manufacturing. Kepstan® PEKK can be printed directly in either the amorphous or semi-crystalline state, or printed amorphous and crystalline in a secondary process, offering the ultimate combination in performance and processing flexibility.     CHEMICAL COMPOSITION AND STRUCTURE PEKK : Structure: PEKK consists of ether (O) and ketone (C=O) linkages, with two ketone groups in the repeating unit. This structure provides high thermal stability and chemical resistance, making PEKK ideal for demanding environments. PEAK : Often confused with PEKK, PEAK is a general term referring to various types of polyetherketones. It includes polymers with similar structures but s...

Today's KNOWLEDGE Share What are the Pros of 3D Printing? 1. Flexible Design 3D printing allows for the design and print of more complex designs than traditional manufacturing processes. More traditional processes have design restrictions which no longer apply with the use of 3D printing. 2. Rapid Prototyping 3D printing can manufacture parts within hours, which speeds up the prototyping process.This allows for each stage to complete faster.When compared to machining prototypes,3D printing is inexpensive and quicker at creating parts as the part can be finished in hours,allowing for each design modification to be completed at a much more efficient rate. 3. Print on Demand Print on demand is another advantage as it doesn’t need a lot of space to stock inventory, unlike traditional manufacturing processes.This saves space and costs as there is no need to print in bulk unless required. 3D design files are all stored in a virtual library as they are printed using a 3D model as eit...

Today's KNOWLEDGE Share Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide: The reinforcing effect of graphene oxide (GO) in enhancing the flexural strength and flex modulus of aramid fiber (AF)/epoxy composites were investigated with GO-AFs at a weight fraction of 0.1-0.7%. The flexural strength and flexural modulus of the composite reached 87.16 MPa and 1054.7 MPa,respectively, which were about 21.19% and 40.86% higher than those of the pure epoxy resin. In addition, the flexural properties and interfacial shear strength (IFSS) of composite reinforced by GO-AFs were much higher than the composites reinforced by AFs due to GO improved the interfacial bonding between the fiber& matrix. Graphene possesses many remarkable properties, including high Young’s modulus (1100 GPa),superior fracture strength (125 GPa),large surface area (2630 m2/g).Due to these excellent properties, graphene and its derivatives, in particular grapheneoxide (GO) ,have found i...

Today's KNOWLEDGE Share  Acrylic (PMMA) vs. Polycarbonate (PC)  : Acrylic offers greater tensile strength than polycarbonate, typically around 80 MPa, compared to polycarbonate at 60-70 MPa. That means it can stretch a bit more before breaking. Similarly, acrylic wins the battle for flexural strength at 115 MPa vs. 90 MPa for polycarbonate, set a heavy object on unsupported sheets of each and PC will give way first (but not by much). Both polymers are quite impact resistant, but where acrylic comes in around 17 times that of glass, polycarbonate boasts a whopping 250x increase. However, polycarbonate is more prone to scratching than acrylic, but as many eyeglass wearers know, coatings are available to avoid this common problem. There's little difference in transparency between acrylic and polycarbonate (92% light transmission for acrylic vs. 88% for PC). Glass straddles the two at 90% transparency. Leave these two polymers outside for a few years, however, and you’ll have no p...

Today's KNOWLEDGE Share A local temperature increase in excess of 100°C is absolutely a realistic number for the thin high shear layers in Injection Molding. Because this high T will last often less than a second (filltimes are short, the cold steel mold is extremely close), such high melt T will not necessarily result in a very visible quality loss, like discoloration. This high shear-heating also happens in your barrel if you push RPM and backpressure up. However, testing for melt T plunging a thermocouple on the purged melt will hardly measure a significant change in average temperature, because the very hot layer is extremely thin (small overall volume fraction). Despite the small volume involved in possible degradation, significant issues may arise, like VOC (volatile organic compounds) degassing, which will mess with your process and parts. The message is : be aware that due to the low thermal conducivity of plastics, heating will be very localized (adiabatic) and will be dif...

Today's KNOWLEDGE Share The BOTTLE4FLEX project: developing 100% recyclable food packaging: The European Union’s Circular Economy Strategy stipulates that all plastic packaging in the European Union must be 100% recyclable by 2030. This is a particular challenge for food-contact packaging. Recycling flexible PET packaging is tricky because it is made up of layers but in Spain, recycled polyethylene terephthalate (rPET) is the only type authorised for post-consumer recycled content for food packaging. AIMPLAS, the Plastics Technology Centre, Covinil and Eroski took up this challenge by launching the BOTTLE4FLEX project which aims to develop 100% recyclable flexible skinpack packaging using rPET. 'Skinpack' is the type of clear packaging which clings closely to the product, so that consumers can actually see what they are thinking of buying while producers and distributers get the benefit of cost-effectiveness and flexibility. Unfortunately, these advantages ...