Novel value-added thermoplastic elastomers bonding to polyamides

Bonding thermoplastic elastomers to polar and non-polar substrates has been widely studied in the past few decades to create products that enhance ergonomic comfort and functionality. Overmolding a TPE compared to two-shot molding is a litmus test for bonding the material to the substrate. The TPE must wet the cold surface and must melt a few nanometers of the surface of the substrate that is being overmolded on to facilitate bonding.

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Recyclate based composite TPO membrane for embedded waterproofing of concrete roofs

Preformed membranes are primarily made from EPDM, PVC, TPO, HDPE, atactic PP, SBS and modified bitumin, etc. The focus of this article is TPO membranes, which are extensively used for exposed roof waterproofing and heat insulation. First introduced in Europe in the early 1990s, TPO membranes were developed as an alternative to PVC to overcome issues around plasticizer migration and membrane integrity breakdown, resulting in wash away and chemical contamination, as well as mold growth affected by weathering over the years; and finally culminating in cracking and leakages. TPOs have since become very popular due to their durability, UV and heat resistance, energy efficiency, as well as cost-effectiveness.

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Fumed silica benefits mechanical properties of TPU prepared by in situ polymerization

Fumed silica is widely used as a reinforcement additive in silicone elastomers with significant mechanical property benefits, namely increased tensile strength, elongation and tear strength, among others. However, the use of fumed silica in thermoplastics is limited because of the difficulty to effectively add them via melt compounding by an extruder. Fumed silicas are extremely light; they have a bulk density of about 50 to 100 g/l. Thus, feeding this low density powder into the extruder, as well as conveying and mixing it with a viscous polymer melt, presents a challenge in typical plastics compounding operations.

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Software based tape stacking with the aid of camera technology paves the way for thermoplastic composites

Thermoplastic tapes are expected to achieve great things, namely to shape the next generation of thermoplastic composites. This calls for highly accurate tape stacking. At the same time, tape processing must not become so complex that it becomes uneconomical. Engel contributes this technology to achieve a breakthrough by combining high precision control software with camera technology in tape stacking.

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HeatBoss EPDM: High heat resistant EPDM promising for SAE J200 applications

In modern cars, the space for the engine compartment is continuously shrinking for both functional and aesthetic reasons. Increasing vehicle compactness by reducing the space available for design engineers results in hotter engine components which restrict the rubber materials that can be used. This has boosted a fast growing demand in the rubber industry for elastomer parts with durability and increased resistance to temperature extremes. Among elastomers, silicone elastomers and fluoroelastomers show very effective heat resistance resulting from the strong Si-O and C-F bonds present in their chemical structure. However, the main drawbacks are their high price and high processing cost that make compounding, molding and final production very expensive

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Total Cray Valley industrializes sustainably sourced Krasol diols

Total Cray Valley is expanding its hydroxyl-terminated diene resin portfolio with the industrial introduction of sustainably sourced farnesene-based resins, Krasol F3000 and Krasol F3100. The Krasol product line is known in the market as a source of well-defined hydroxyl-terminated liquid poly(butadiene) diol and monol grades. These materials are used in a variety of end-use applications as components in urethane, epoxy and UV-cured adhesive and sealant formulations for the automotive and electronic markets. The diene backbone incorporates hydrophobic quality and chemical resistance, as well as elastomeric softness and low-temperature performance.

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DuPont rebrands silicone masterbatches for thermoplastics as MULTIBASE products

DuPont Mobility & Materials announced that it has rebranded its full portfolio of silicone masterbatches for thermoplastics as MULTIBASE™ products. The new brand took effect this month and applies to all legacy Dow Corning silicone-based masterbatch products

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Adhesion of thermoplastic elastomers on polycarbonates for medical wearables

Thermoplastic elastomers (TPEs) and polycarbonates (PCs) offer an interesting combination of rigid and soft materials for housings and interfaces in wearable applications. However, strong adhesion between TPE and PC materials is critical to achieve durable devices that can withstand repeated use. A recent study conducted by Covestro and Teknor Apex, “Adhesion of TPEs on Polycarbonates for Medical Wearables,” examined the adhesion and chemical resistance of medical grade resins that are candidates for wearable applications. In the study, the team evaluated the adhesion of newly introduced TPE grades designed specifically for overmolding on various medical grade PC substrates.

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Highly resilient Santoprene thermoplastic vulcanizate for automotive Sealing systems

Thermoplastic elastomers (TPE) are a class of materials that combine the advantages of a rubber, such as excellent compression set for good sealing, with the processability of conventional thermoplastics. Thermoplastic vulcanizate (TPV) is a subset of TPEs produced from a blend of vulcanized-crosslinked rubber finely dispersed in a continuous thermoplastic matrix. TPVs are produced by dynamic vulcanization, whereby a rubber is cured/ vulcanized within a thermoplastic polymer while the polymers are undergoing intimate mixing or mastication at elevated temperatures. Elasticity, tensile properties and hardness of the TPV are controlled by the ratio of the harder thermoplastic phase to the softer rubber phase. It is well known that TPVs exhibit the advantageous sealing properties of conventional cured rubber, excellent physical properties, good high temperature resistance and outstanding chemical resistance. Due to these benefits Santoprene TPVs have become a workhorse material for a variety of automotive sealing applications. The applications for TPVs in automotive sealing include glass run channels, dynamic seals, cowl vent grille seals and outer belt line seals

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Programmable shape change in bio-inspired thermoplastic elastomer bilayers

In this study, Engage polyolefin thermoplastic elastomers (POEs) from Dow Chemical are used, which are random ethylene-octene copolymers with relatively low melting temperatures (Tm), and elastic recovery that is tunable and dependent on comonomer content. POE bilayers are molded, but unlike other natural and synthetic systems, each layer does not contain any anisotropy. So there is no orientation difference between the layers. Upon stretching and releasing, the bilayers exhibit bending, curling and twisting, depending on the elastic recovery difference between the layers and the applied strain. This has been termed mechanical programming. The shape change can be further controlled through the length (L) to width (W) ratio, L/W, of the formed bilayers

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