Name | PMMA Board |
Synonyms | PMMA Board |
Use | PMMA generally refers to polymethyl methacrylate. Polymethyl methacrylate (polymethyl methacrylate), abbreviated as PMMA, is a high molecular polymer, also known as acrylic or plexiglass. It has the advantages of high transparency, low price, easy machining, etc. It is a commonly used glass substitute material. |
polymethyl methacrylate (poly(methylmethacrylate), abbreviated as PMMA), also known as acrylic, acrylic (English Acrylic) or plexiglass, Lucite (commodity name), is often called Agari glue in Hong Kong, China. It has the advantages of high transparency, low price, easy machining, etc. It is a commonly used glass substitute material.
The monomer of polymethyl methacrylate is methyl methacrylate (MMA, acrylic monomer).
Polymethyl methacrylate is often used as a substitute for glass. The properties of the substance are as follows:
Physical properties
1. The density of PMMA is lower than that of glass: the density of PMMA is about 1.15-1.19g/cm3, which is half of glass (2.40-2.80g/cm3) and the 43% of metal aluminum (belonging to light metal).
2. The mechanical strength of PMMA is relatively high: the relative molecular mass of PMMA is about 2 million, which is a long-chain polymer, and the chain forming molecules is very soft. Therefore, the strength of PMMA is relatively high, and its tensile and impact resistance are 7-18 times higher than that of ordinary glass. There is a kind of organic glass that has been heated and stretched, in which the molecular segments are arranged in a very orderly manner, which significantly improves the toughness of the material. Nail into this plexiglass with nails, even if the nails penetrate, no cracks will occur. This kind of plexiglass will also not break into pieces after being penetrated by bullets. Therefore, the stretched PMMA can be used as bulletproof glass and also as a cockpit cover on military aircraft.
3. PMMA has a lower melting point, much lower than the high temperature of about 1000 degrees of glass.
4. PMMA has higher light transmittance
(1) Visible light: PMMA is currently the most excellent polymer transparent material with a light transmittance of 92%, which is higher than that of glass.
(2) Ultraviolet light: Shi Ying can completely transmit ultraviolet rays, but the price is high. Ordinary glass can only transmit 0.6% ultraviolet rays. PMMA can effectively filter out ultraviolet light with wavelength less than 300nm, but the filtering effect is poor between 300nm and 400nm. Some manufacturers coat PMMA surfaces to increase the effect and properties of filtering out ultraviolet light from 300nm to 400nm. On the other hand, PMMA has better stability than polycarbonate under the condition of irradiating ultraviolet light
(3) Infrared: PMMA allows infrared (IR) with a wavelength less than 2800nm to pass through. Longer wavelength IR, less than 25,000nm, can be basically blocked. There is a special colored PMMA, which can allow specific wavelengths of IR to pass through while blocking visible light (for remote control or thermal induction, etc.).
(4) The glass transition temperature of PMMA is about 105°C.
Chemical properties
Due to its large branched chain and high viscosity of polymethyl methacrylate, the processing speed is relatively slow when using thermal processing methods. The plexiglass can not only be cut by a lathe and drilled by a drilling machine, but also can be used Acetone, chloroform, etc. are bonded into various shapes of appliances, and can also be processed into various products as large as the cockpit cover by blow molding, injection, extrusion and other plastic molding methods.
Cyanoacrylate, dichloromethane or chloroform can slightly dissolve plexiglass, and then two pieces of plexiglass can be firmly bonded together.
To produce 1kg of PMMA requires about 2kg of oil. In the case of oxygen, PMMA starts to burn at 458°C. After burning, it produces carbon dioxide, water, carbon monoxide and some low molecular compounds including formaldehyde
PMMA has the advantages of light weight, low price, and easy molding. Dissolved in organic solvents such as anisole, etc., can form good films and good dielectric properties, and can be used as a dielectric layer for organic field effect transistors. [1]
Its molding methods include casting, injection molding, machining, thermoforming, etc. In particular, injection molding can be mass-produced, with simple process and low cost. Therefore, its application is becoming more and more extensive. It is widely used in instrument parts, automobile lights, optical lenses, and transparent pipes.
Application of plexiglass acrylic (acrylic) in construction industry. plexiglass acrylic (acrylic) is mainly used in building daylighting, transparent roof, roof, telephone booth, stairs and room wall guards. Sanitary ware includes bathtub, washbasin, cosmetic table and other products. The application of highway and high-grade road lighting lampshades and automobile lamps is also developing rapidly. Among them, the market for building lighting bodies, bathtubs, street advertising light boxes and telephone booths has grown rapidly, and there is a large space for future development and a very broad market prospect.
With the construction of hotels, hotels and high-end residential buildings in major cities, Chinese architectural daylighting has developed rapidly. The daylighting body made of plexiglass acrylic (acrylic) extrusion plate has the special advantages of high overall structural strength, light weight, high light transmittance and high safety performance. Compared with inorganic glass daylighting, it has great advantages.
The United States and Japan have made mandatory provisions in the law that plexiglass acrylic (acrylic) must be used for building glass for primary and secondary schools and kindergartens. With the continuous improvement of Chinese laws and regulations, it is expected that in the near future, Chinese laws will also stipulate that the architectural glass of primary and secondary schools and kindergartens must also use plexiglass acrylic (acrylic). At the same time, all parts of China have accelerated the pace of urban construction, and a large number of street signs, advertising light boxes and telephone booths have appeared. A considerable part of the materials used are plexiglass acrylic materials.