Polyacrylic
Rubbers > Group M
Acrylic rubber (ACM) | ||||||||
Acrylate polymers and copolymers Polyacrylic elastomers, also called ACM rubbers, are synthetic rubbers composed of acrylic monomers. They have good resistance to oxygen and ozone even at high temperatures of 150 ° C, to degradation and to UV rays, they are used especially for coatings and to give impact resistance to some plastics. Despite the presence of potentially active side groups for vulcanization, polyethyl acrylate is not vulcanizable with peroxides. ACM rubbers have excellent resistance characteristics at high temperature 150 ° C, aging, oils and solvents. Due to the fact that they do not have unsaturated bonds in the polymer structure, they have good resistance to heat, oxygen and ozone. Compared to the more economical NBR with medium and high acrylonitrile content, they have a comparable oil resistance, but they resist better at high temperatures, especially in the presence of oils containing additives based on sulfur substances that cause over-ulcanization of the nitrile gums and determine their loss of elastic properties. They are expensive and are used mainly in aeronautical applications. | ||||||||
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Characteristics of rubber | ||||||||
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Physical-Mechanical Properties | ||||||||
The ethylene acrylate copolymers, AEM, are synthetic rubbers composed of ethylene and acrylic monomers. Ethylene imparts good properties at low temperature, while the acrylic portion improves oil resistance. The combination of a saturated spine with polarization, also provides a good resistance to heat, ozone (outdoors) and many chemicals. In general, the resistance of AEM to oxygen is higher than that of the ACM. In addition to excellent resistance to heat and ozone, the AEM have exceptional vibration and good performance. Polyacrylate (ACM) compounds are designed to withstand high temperatures without losing resistance to hydrocarbons. Specially designed for applications in sulfur oils. ACM elastomers are also resistant to oxidation, ozone, aliphatic solvents, sunlight and weather and have a low gas permeability. Polyacrylic rubbers are able to withstand high temperatures but their resistance to low temperatures is relatively poor. | ||||||||
Como se obtiene el caucho sintetico - Obtencion del caucho sintetico | ||||||||
Le gomme di poliacrilato sono elastomeri preparati da esteri acrilici (tipicamente etile e metil acrilato) e monomero di cura reattiva (acido carbossilico o cloroetilviniletere). Los ACM son producidos por polimerización de radicales en emulsión (excepcionalmente por suspensión). Para su iniciación se utilizan peróxidos, compuestos azoicos o sistemas de iniciación de oxidación-reducción. Debido al hecho, ese pH de reacción debe ser> 7, para evitar su hidrólisis. La misma influencia negativa también puede ser rellenos u otros aditivos de carácter ácido en sus compuestos. Las unidades principales de repetición son acrilato de etilo y butilo o una mezcla de ambos. Una gran variedad de propiedades termofísicas y mecánicas. Muy común es la adición de 5 por ciento de 2-cloroetil vinil éter. Se han desarrollado varias modificaciones de copolímeros para mejorar las propiedades de los ACM. Las modificaciones incluyen otros monómeros de esqueleto y la incorporación de grupos de sitios reactivos (1-5%) para la reticulación posterior. | ||||||||
ACM Rubber applications | ||||||||
ACM elastomers are used when combined resistance to heat and oils is required for applications at elevated temperatures (<150 ° C). Typical applications include automotive transmission components such as seals and hoses that must be resistant to hot oil, fuel and many other lubricants and hydraulic fluids common to automobiles. The ACM elastomer has also been found in vibration damping due to its excellent recovery capacity. Other applications include textiles, adhesives and coatings. Other typical applications include automotive transmission / power steering seals and o-rings. Other applications include diaphragms, plumbing seals, boots, hoses, vibration mounts, pads, insulators and custom molded rubber parts and articles. | ||||||||