Sipolprene®

Product Range

Sipolprene® ether ester thermoplastic elastomer (TPC-ET) are engineering polymers, which are made through the combination of rigid polyester blocks (crystalline segment) and flexible long-chain polyether blocks (amorphous segment). By varying the structure of these blocks, it is possible to determine the final properties of the polymers. This modifies the polymer characteristics as concerns mechanical properties vs temperature, gas permeability, and chemical resistance.

The double soul of the Sipolprene® macromolecular chain, (polyester-rigid and polyether-soft) allows the polymer to match the qualities of flexible plastics with the performance of thermoplastic elastomers. As thermoplastic elastomer, it can easily be processed by using many different techniques, such as injection molding, extrusion, blow molding, etc.

At microscopic level, the resulting structure, which is a block copolymer made of short hard segments alternating with long flexible segments, is biphasic in morphology. The presence of hard polyester blocks assures heat resistance, chemical resistance and easy processing; amorphous polyether regions improve softness and elasticity, directly connected to the material hardness. One of the most important characteristic that makes Sipolprene® different from most engineering plastic resins and thermoplastic elastomers is that all Sipolprene® products, due to their block copolymer structure, show mechanical characteristics like modulus, tenacity and resilience that are less affected by temperature variations. This higher mechanical performance constancy makes Sipolprene® the right engineering choice for applications where a high standard is required for safety or reliability reasons.

The more the hard-block content (rigid polyester), the higher the hardness and they pass from essentially elastomeric polymers (28 - 45 Shore D) to plastomeric ones (53 - 72 Shore D). The result is an increasing load, stiffness, tear, creep, chemical and temperature resistance. Equally, there is a decrease in fatigue and impact resistance. Their field of application covers a wide temperature range, starting from -65°C up to 185°

Specialty grades are available with: low viscosity, high viscosity, heat stabilized, UV stabilized, metal de activated for high performance cable jacketing, hydrolysis stabilized, Improved NO resistance, enhanced lubrication, Black coloring through masterbatch dry blending.

Chemical resistance

Having a polyester skeleton, Sipolprene® generally shows good resistance to grease and to hydrocarbons. However, Sipolprene® become less stable when in contact with polar solvent, i.e. hot water, concentrated acids and/or bases, and alcohol above temperatures of 60°C .

Applications

Extrusion

The range of viscosity of Sipolprene ® makes them typically suitable for injection moulding. However, they may be processed in extrusion, adjusting the temperature profile in the extruder, as low as possible in order to gain melt strength and output stability.

Injection Molding

Standard injection molding screws can be used. The injected product weight should be in a range between 40% and 70% of the maximum shot capacity, and therefore the machine and relative barrel diameter should

be compatible with these values. The screw should have a L/D ratio of from 17 to 23 and a thread depth ratio of 1:2. A check valve is also recommended. Nozzles should be short in order to minimize friction and pressure loss. The hopper must have a tight-fitting lid to keep the pellets dry during processing. Sipolprene® exhibits good thermal stability at the temperatures required for manufacturing (from 160 to 240°C). This minimizes the problem of viscosity decrease during the hold-up time in injection and the formation of degradation byproducts. Besides, SIPOLPRENE®’s thermal properties also make it possible to use a percentage of reground product (e.g. from process scrubs) mixed to virgin ones during injection.

Sipolprene® reporting “1” as last digit (Sipolprene® 55211 and Sipolprene® 40171) is modified in order to increase crystallization rate, offering faster cycles in injection moulding.

The soft nature of Sipolprene® and its chemical structure, which allows to achieve a good adhesion to several rigid engineering plastics products like ABS, PS, PC, PBT and PVC make it a material of choice in 2K molding application where “soft touch” or functional flexible properties are needed and other thermoplastic elastomers do not provide sufficient adhesion. The table below shows an overview of the adhesion properties of Sipolprene ® and other polymers to several substrates.

Compounding

Thanks to its high compatibility with PVC, PET, SEBS, ABS and TPU, Sipolprene ® is frequently used in compounding as a modifier to improve some specific properties of the final compound. The range of possible modifications, brought on by compounding Sipolprene ® with other polymeric materials, is extremely wide. The most common modifications are, for example, its use in PVC compounds to improve their low temperature resistance and to reduce the amount of added plasticizer. A special Sipolprene® grade called 35150 is available, where melting temperature is lowered to 150°C in order to make it more suitable for temperatures where PVC is compounded. Furthermore, in SEBS compounds, Sipolprene ® can be blended to gain thermal resistance (Vicat) or to modify the adhesion to polar substrates for 2K molding applications.

Breathable applications

Sipolprene® B range has an enhanced water vapor permeability, which allows its use to produce breathable films and membranes.

Air fresheners

Sipolprene® shows superior fragrance absorption together with enhanced slow-release properties, making it the first choice for top-level air freshener carries.

Cables

Electrical properties

A high dielectric constant together with a good dissipation factor make Sipolprene® suitable for low voltage applications where high mechanical properties and resistance to high temperatures are appreciated over traditional thermoplastics. A special Sipolprene® grade for metal de activating for high performance cable jacketing is also available. Sipolprene® also shows very good acceptance of flame-retardant fillers like aluminum trioxide (ATH) and magnesium dioxide (MDH) making it a good choice for HFFR cable compounds.

Portfolio:

Sipolprene® 25170, Sipolprene® 25185, Sipolprene® 35180, Sipolprene® 35195, Sipolprene® 46185, Sipolprene® 55200, Sipolprene® 58210, Sipolprene® 63210, Sipolprene® 68217, Sipolprene® 72220, Sipolprene® 35150, Sipolprene® 40171, Sipolprene® 55211, Sipolprene® B4319, Sipolprene® B5422

Solutions

Compounding & Recycling Masterbatches Packaging Powdering Tubes & Pipes Rotomoulding & Rotolining Cables & Cable Compounding Packaging for Cosmetics, Pharma, Nutra Corks & Closures Roofing, Insulation, Sound Dampening Fibers & Yarns, Monofilaments & 3D Print Filaments Extrusion, Foaming, Thermoforming, Shoes (Non-Packaging) E+E, HOME, OFFICE, INDUSTRIAL, CONSUMER Transports & Mobility Air Fresheners Coatings, Paints, Varnishes, Inks