SMMA
Thermoplastics > Acrylates
| SMMA Copolymers styrene- methylmethacrylate | |||||||||
The SMMA (StireneMetilMetaAcrilato) or methacrylate methyl styrene is a rigid, durable resin. Processing ease, versatility and durability make it an economical solution for a variety of applications. The SMMA resin are styrenic copolymers with excellent transparency and optical properties, excellent resistance to sterilization by gamma radiation, beta and ETO. F ent polystyrene have improved light stability, clarity and toughness and is free of Bisphenol A, therefore can meet the par regulations the contact alimentare (FDA and European regulations) and for applications in the médicales industry (USP VI ). It is ideal for products with large thickness as thin walls. Among its general characteristics can include the following: They must contain at least 30% by weight of styrene parts to prevent degradation at temperatures near 250 ° C. Meet the requirements of transparent plastics with good mechanical properties, dimensional stability, scratch resistance and flexibility, fácilad up processing (requires less temperature need not be dried, provides excellent high gloss and low density. |  | ||||||||
| Properties | |||||||||
SMMA, also known as MS Resins, is a mixture of methyl methacrylate (MMA) and styrene monomer (SM). MMA provides excellent hardness, clarity and weatherability, and SM provides excellent clarity and stiffness, with the combination of the two, creates a suitable cost polymer for applications requiring excellent clarity, with weatherability and scratch resistance. SMMA resin is a transparent resin profitable higher priced alternative as PMMA - Acrylic. |  | ||||||||
| Compared to other transparent polymers | |||||||||
Regarding the PS glass, SMMA thermoplastics have the same ease of similar transformation, but do not need drying, better resistance to UV light, with the same transparency, but have better mechanical properties, miemtras regarding SAN has better lightfastness you do not need pre-drying. You can use leftover mashed production without pollution problems. Some mixtures, have better impact. No doubt about the PMMA has better dimensional, lighter, better impact, similar transparency, stability and needs no drying is cheaper. Also regarding the PC is easier processability, has better transparency, does not need pre-drying is more economical, libero da Bisphenol A. SMMA polymer retains the characteristics of high transparency, scratch resistance and good behavior in large thicknesses similar to PMMA. Virtually no moisture absorption, which offers the advantage of avoiding drying pretreatment. Good processability and slightly larger than the PMMA chemical resistance. |  | ||||||||
| Polimerization | |||||||||
Initiating radical polymerizations it can be completed by various procedures. In all cases, the production of free radicals, which then induce polymerization, usually the determining step initiation. The initiation and therefore generally can be considered that elapses in two stages: the first is the formation of a free radical and the second free radical esla addition to a monomer or pre-polymer to form a radical chain. From here you can continue the spread and growth of lascadenas by reaccionesradicalarias. The procedure elcualse form a free radical in the first stage of initiation vary eltipode initiation occurs.The polymerization progresses in a short time, usually producing a high conversion of monomer to polymer without the oxygen in the air to be a problem. However, the polystyrene obtained by estemétodo is amorphous, with a distribution of very broad molecular weight and very poor mechanical properties. Monomers such as styrene and methyl methacrylate, which are neither very electrophilic or very nucleophilic, polymerizes by chain polymerization mechanisms of free radicals. Styrene can be used even undistilled, ie with inhibitors polymerization monomer carrying only necessary to add a small excess of initiator. |  | ||||||||
| Applications | |||||||||
Styrene Acrylic Copolymers (SMMA thermoplastics), p ou be used both for injection and extrusion blow molding. Its uses are similar to those of PMMA, SAN or PS. It can replace PMMA resins, acrylic based polymers and other transparent polymers such as PC, the main advantage is a significant reduction in costs and a simpler transformation. Tubes biochemical laboratories, drug packaging, or tensilios cooking, or optical sos. |  | ||||||||