Polycarbonate copolymers and blends improve properties, Polyurethane Foams

Polycarbonate copolymers and blends improve properties

SABIC Innovative Plastics has added new grades of polycarbonate copolymer grades to the three that have been in commercial use since 2001. SABIC calls this new family of copolymers as �Extreme performance portfolio�. Each of these copolymers is designed with optimization of a property or a set of properties. They intend to broaden the processing and performance window of the conventional PC grades. These tailor made grades are:
• Lexan EXL � A copolymer of PC with silicone rubber. It combines extreme ductility, chemical resistance, and impact retention under exposure to heat, humidity and UV radiation.
• Lexan EXL 8414 � A copolymer of PC with silicone rubber, also contains maximum of 25% post-consumer recycled PC from 5 gal water bottles.
• Lexan HPX for heath care market. It has enhanced flow, release, and autoclave performance at 121°C.
• Lexan SLX is an outdoor weatherable grade that minimizes yellowing and embrittlement. It needs no UV stabilizer or coating, because a portion of the polymer is activated by UV exposure to create a protective layer over the polymer
• Lexan FST is designed to comply with flame, smoke, and toxicity (FST) limits, as well as low heat release, for materials used in aircraft interiors, ships, and railroad cars. It is said to be the first clear material to meet FST requirements for aerospace uses without a waiver. Another new new development in the Lexan FST series is a transparent grade that could be the first plastic to replace glass in aircraft interior applications such as large lighting domes, cabin dividers, and seating components.
• Lexan HFD ( high flow & ductile) provides very high flow-about 40% greater than standard PC-without the usual tradeoff of toughness or ductility for flowability that is typical in standard PC. High flow of Lexan HFD provides superior optics with low birefringence due to reduced molded-in stresses. Lexan HFD is aimed at camera lenses, safety eyewear, medical housings, consumer electronics, bezels, and appliances. It is currently available in five grades, some with UV stabilizers. Glass-filled, flame-retardant, and food-contact grades are in development, as are blends with other SABIC engineering resins.
• Lexan XHT (extra-high-temperature) are clear, flame-retardant grades for use temperatures from 140°C to 195°C.
• Lexan DMX offers better scratch resistance due to three times hardness compared to the typical PC grades.
Bayblend M850XF, a polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blend from supplier Bayer MaterialScience is aimed squarely at processors of medical devices, with the material bringing impact resistance, stiffness, dimensional and color stability. The grade satisfies the biocompatibility requirements of ISO 10933 Part 1 as modified by the FDA (Food and Drug Administration). Parts made with the new blend can be sterilized using ethylene oxide, gamma radiation, and electron rays. The supplier is targeting processors of opaque medical applications such as components for surgical instruments, diagnostic equipment, systems administering drugs and intravenous systems. According to Bayer, it is well suited to molding of thin-walled components. Bayer MaterialScience�s Glass fiber-reinforced PC/blend resin offers suppliers and OEMs an easy, environmentally friendly transition from styrene maleic-anhydride resins. Bayblend® T88 GF-10 glass fiber-reinforced polycarbonate/blend (PC/blend) resin is a replacement for applications, such as instrument panel retainers, center consoles, and other interior structural parts, which previously used SMA resins. Interior part suppliers have designed tools to fit SMA's unique shrink rate range, and typically, alternative materials do not fit the same tools. However, this particular PC/blend resin from Bayer MaterialScience has the same shrink rate range as SMA resin, allowing OEMs to continue to use existing tooling for their automotive interior applications. The PC/blend resin reduces the problem of a high in-process scrap rate that OEMs experienced with SMA resins. Other advantages that the resin offers include a higher flow, improved surface cosmetics, better heat aging performance and good adhesion to polyurethane foams, offering lower volatile organic compound (VOC) emissions when compared with the glass-filled SMA resins, making it a more environmentally friendly option.
Impact strength properties of PC-based resins blended with ABS are enhanced thanks to the addition of Elvaloy® EAC1125. DuPont�s impact modifiers offer better process ability of the compound thanks to reduced melt viscosity, better UV and thermo stability, higher elongation, easier handling and processing due to pellet form instead of powder.