Polyesters, thermoplastic, minerals

The minimum service temperature is determined primarily by the Tg of the soft phase component. Thus the SBS materials ctm be used down towards the Tg of the polybutadiene phase, approaching -100°C. Where polyethers have been used as the soft phase in polyurethane, polyamide or polyester, the soft phase Tg is about -60°C, whilst the polyester polyurethanes will typically be limited to a minimum temperature of about 0°C. The thermoplastic polyolefin rubbers, using ethylene-propylene materials for the soft phase, have similar minimum temperatures to the polyether-based polymers. Such minimum temperatures can also be affected by the presence of plasticisers, including mineral oils, and by resins if these become incorporated into the soft phase. It should, perhaps, be added that if the polymer component of the soft phase was crystallisable, then the higher would also affect the minimum service temperature, this depending on the level of crystallinity. 

Typical systems are unsaturated polyesters, usually filled with mineral fillers and/or fibres. Newer systems such as thermoset-thermoplastics using reactive solvents for processing high-performance engineering polymers are being researched. 

Pocan . [Bay6r] PBT w PET polyester, some glass at mineral reinforced engineering thermoplastic for automotive, consumer, industrial/mech., elec elec-tionic markets. 

Talc - Talc is a filler made by dry or wet grinding of mineral magnesium silicate. Talc improves stiffness, dimensional stability, flexural modulus, creep resistance, flow, surface smoothness, moisture resistance, tensile strength, and wear resistance of plastics. It also increases heat deflection temperature and decreases vapor permeability. Can be used as a film antiblock agent. Used mainly in polypropylene but also in thermoplastic and unsaturated polyesters and epoxy resins at low levels. Surface-modified grades are available. 

It is well accepted that the good properties of the isotactic polypropylene as an engineering polymer matrix in thermoplastic composite materials and engineering blends are seriously affected by the inability of this polymer to develop an adequate level of interfacial interaction with polar components such as mineral fillers (calcium carbonate) and reinforcements (talc, mica, wollastonite), synthetic reinforcements (glass fibers, carbon fibers, and nanotubes), or engineering polymers such as polyamide, aliphatic polyesters, and so on. 

Polycaprolactone Poly-e-caprolactone (PCL) is a semicrystalline, thermoplastic, linear aliphatic polyester synthesized by the ring-opening polymerization of e-caprolactone and is produced commercially by Union Carbide-Dow (Midland, MI) and Rhone-Poulenc (Collegeville, PA). This polymer has a melhng point of approximately 62°C and a glass transihon temperature of approximately -60°C. PCL is readily degraded and mineralized by a variety of microorganisms [45] ... 

The multiple functions of mica have been outlined in Chapter 1 of this book, along with an example of its role in the search of multifunctional fillers for polypropylene compounds for automotive applications. Mica-reinforced thermoplastics such as polypropylene, polyethylene, nylon, and polyesters are now established in a variety of automotive applications and consumer products where mica supplements or replaces glass fibers and other mineral fillers. The wider use of mica in many applications has been limited by low impact strength and low weld-line strength in certain plastics. These issues are the focus of continuing R D efforts by materials suppliers and compounders/molders. 

Description Aminosilane surface-treated grades, giving improvements in physical properties compared with untreated fillers, esp. low warpage, high impact strength specially developed for mineral-filled polyamides can also be used in polyesters, urethane, PVC and other thermoplastics white colour ... 

Automotive and electrical/electronics industries are the largest markets for engineering polymers which include Crastin PBT polyesters, Hytrel thermoplastic polyester elastomers, Rynite PET, high-temperature Thermx PCT (polycyclohexylene dimethyl terephthalate), Tribon composites and Tynex filaments, Vespel polyimide parts and shapes, Zenite liquid crystal polymers and Zytel PA resins. In July 2005, DuPont launched the DuPont Vespel SP-202 composition whose properties include the prevention of static charge build-up. Other products include Delrin acetal resins, engineering thermoplastic vulcanisates. Minion mineral reinforced PA resins and Teflon PTFE fluoropolymer resins. 

Long branches, novel chain polymers have also been produced by the addition of appropriate substrates in the culture medium [15]. The different polyesters obtained with this technology can be thermoplastic or elastomeric and that containing valeric and butyric monomers are mineralized. 

These high concentrations of FR minerals tend to increase part density and brittleness. Some polymers can react with them as well. Thermoplastic polyester like PBT caimot be used with them for this reason. The big advantage of these inorganic materials is low cost as well as their white or light color and the nontoxic benefits. Sometimes they are used at low concentrations with other FR materials as cost savings additives. Sometimes they provide other benefits in certain electrical applications like ion sequestration. 

Hot-Applied Rubberized Asphalt. Hot-applied rubberized asphalts consist of proprietary blends of asphalt, mineral fillers, elastomers (natural, synthetic, or a blend of both), virgin or reclaimed oil, and a thermoplastic resin. It is applied hot in such a manner as to form an impermeable monolithic membrane over the surface to be waterproofed, which may be concrete, gypsum board or wood. Improved versions of this type of system consist of two coats of rubberized asphalt with a polyester mat in between, ealled the fully reinforced or two-ply system. 

GE Plastics Valoy thermoplastic polyester resins product line includes grades from 100% unmodified PBT resins to eombinations of glass fibre-reinforced, mineral filled, mineral/glass-reinforced and flame resistant grades. PC/PBT grades are sold under the Xenoy trade name. 

Crystalline polymers show the greatest interaction with minerals. In amorphous polymers, minerals merely increase stiffness, with little or no reinforcing effect. Polypropylene, high density polyethylene, thermoplastic polyester and polyamides are crystalline polymers. Low density polyethylene, polystyrene and polycarbonate are amorphous. 

Fibrous reinforcements, such as glass and asbestos, and acicular reinforcements, such as wollastonite, also tend to orient parallel to the flow direction. Since they all have lower thermal expansions than plastics, use of these minerals tend to promote warping, especially in crystalline polymers. Fillers such as mica, talc and kaolin, also orient in the flow direction, but their platy, more two-dimensional shape does not contribute to warping. High aspect ratio mica, because of its extreme platiness, is used to counteract the natural warping tendency of highly crystalline thermoplastic polyesters. 

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