Polymethyl methacrylate (PMMA), commonly known as plexiglass, acrylic, etc., is an amorphous plastic formed by the copolymerization of MMA monomer and a small amount of acrylates. It has good transparency, optical properties and weather resistance. , chemical resistance, impact resistance and aesthetics, it is an advanced material known as the "Queen of Plastics" and its products include molding compounds, extruded boards and injection molded boards.
With excellent optical performance, PMMA is widely used in downstream processes, among which the main applications of low-cost PMMA are advertising light boxes, signs, lamps, bathtubs, tools, daily necessities, furniture, etc., and high-quality materials . PMMA end is mainly used in liquid crystal display screens, radiation PMMA, optical fibers, solar photovoltaic cells, automobile lampshades, bulletproof glass, aircraft cabin glass, medical polymer materials, military optical equipment, high-speed railway windows, police shields. diving goggles, etc. The Second Five-Year Development Plan was included in the Twelfth Five-Year Plan key list for the development of high-quality petrochemical and chemical products. Especially in recent years, the rapid development of the liquid crystal display field has led to a rapid increase in the demand for optical grade PMMA materials.
In terms of performance and use, PMMA is divided into general purpose, heat resistant, optical and impact resistant. With the rapid growth of the liquid crystal display market, the use of high-quality optical PMMA has increased significantly. Applications are constantly evolving in areas such as sheet metal and automotive light weight. The demand for PMMA in my country is expected to grow. maintain relatively high growth rates in the future.
Main applications of PMMA
Light guide plate for display field
Light guide plates for liquid crystal displays are one of the fastest growing applications for PMMA. The backlight module in the LCD panel is mainly composed of three parts: light source, light guide plate and optical film. The light guide plate is mainly used in the LCD backlight module to evenly guide the light emitted by the light source onto the display surface. , The main material is PMMA.
The global flat panel display industry is concentrated in South Korea, Taiwan, Japan and mainland China. With widescreen mobile phones, TV sizes, automotive displays and public display displays, the global new display industry is showing a continuous growth trend. .
In recent years, with the rapid growth of aftermarket demand and the support of relevant national industrial policies, domestic display panels and materials have been developed rapidly. The growth of the panel manufacturer group represented by China has led to the rapid development of the flat panel display production chain in mainland China. The trend of continuous transition of the panel industry to the domestic market is evident. LCD TVs. The market share will exceed 40% and is expected to exceed 50% by 2022, further driving demand for light guide plates.
In the field of lighting, LED lighting is a new type of green light source. Compared with traditional light sources, LED lighting has the characteristics of energy saving, environmental protection, long service life, small size, etc. Widely used in various indications, displays, decorations, backlight sources, general lighting and urban night scenes . At present, LED has become a cost-effective environmental light source and has comprehensively entered the lighting replacement market. In line with the general trend of phasing out incandescent lamps and limiting the use of fluorescent lamps (containing mercury) worldwide, the global solid-state lighting market has grown rapidly, becoming a leap in the history of human lighting, recognized as the most promising source of electric light in the 21st centuryeke.
In line with the world's accelerated phasing out of incandescent light bulbs, my country's LED industry has grown rapidly in recent years, driven by the rapid growth in LED penetration. The application market continues to rise. From 2014 to 2018, the cost of LEDs in my country continues to rise, reaching 267.9 billion yuan in 2018, an increase of 5.0% year on year.
Total size of LED lighting industry in my country (RMB 100 million)
LED panel lights are LED lighting products widely used for indoor (residential, office buildings, retail stores) and outdoor (road, landscape) lighting. surface light sources., so that the light is evenly emitted from the front side of the light panel, effectively expanding the coverage area of the light source. High-end LED panel lights (mainly used indoors) mainly use PMMA light guide plates as raw materials, which have higher light transmittance. Compared with traditional light sources, LED light sources have many advantages such as energy saving, environmental protection, long service life and stable light source.
PMMA fiber material
Plastic optical fiber made of PMMA material is an excellent means of data transmission over short distances. It is considered the best solution for the last mile of fiber to the home (FTTH), and is in line with the national industrial development direction of "light to copper, low carbon, energy saving and environmental protection." Worldwide, the main companies producing plastic optical fibers are Japan's Mitsubishi, Asahi Kasei, and Toray, as well as Boston Corporation in the United States.
After many years of hard work, Chinese scientists have mastered a complete set of technologies for purifying raw materials and directly drawing plastic optical fibers through bulk polymerization. The Institute of Physical and Chemical Technology of the Chinese Academy of Sciences has successfully developed a fully automatic assembly line with a capacity of 100,000 meters of plastic optical fiber per day, which stably produces PMMA optical fiber with an optical attenuation of 170-200dB/km for several months, and has produced millions of meters of plastic optical fiber with low loss.
At the same time, in addition to the field of optical communication, plastic optical fiber is also used in landscape lighting. The landscape engineering for the opening and closing ceremonies of the London 2012 Olympic Games used plastic optical fiber supplied by Shenzhen. Huaying Century Optoelectronics Technology Co., Ltd. At present, the use of plastic optical fiber in landscape lighting in China is still in its infancy, but the development prospects are to be expected.
Composite sheet instead of metal for mobile phone back cover
The back cover of a mobile phone is a new area of application for polymethyl methacrylate. The 5G era is gradually coming. In order to meet the development direction of thinner and more portable, as well as the higher requirements of 5G communication for signal transmission, the composite sheet (PC + PMMA) has become a new mobile phone backplane, which replaces the traditional metal backplate. lid with ceramic and steklom plan.
PC/PMMA Composite Board is made by co-extrusion of PC and PMMA. Because PMMA has good hardness and wear resistance, it is generally used for outdoor applications, and PC has good toughness, so it is used as the inner layer. The PC/PMMA composite board combines the advantages of PC and PMMA, which can not only meet the requirements of rigidity and decoration, but also meet the needs of wireless charging without shielding, and the cost is lower than 3D glass and ceramic.
Performance comparison of composite plate and 3D glass
Lightweight automotive materials
Subsidies for new energy vehicles have been added, and range extension is an important task for automobile companies, and vehicle lightening technology is one of the effective ways to increase range. For every 10% reduction in vehicle weight, its energy consumption can be reduced by 6-8% and exhaust emissions can be reduced by about 4%. Therefore, vehicle lightening is an important new technology for achieving energy development goals. economy, environmental protection and safety.
The key to lightening cars is the use of lightweight, safe and high performance materials. Plastics and their composites, elastomers and carbon fiber composites play an important role in achieving the goal of reducing vehicle weight. Among them, PMMA is widely used in various places of the car body due to its excellent optical properties, light weight and good weather resistance. This is an important area in which PMMA is gradually beginning to be applied.
Automotive headlights: Automobile headlights play the role of lighting and signaling, requiring materials with good light transmission, impact resistance and aging resistance. PMMA is widely used in taillight lampshades of new energy vehicles due to its advantages of light weight, easy coloring and beautiful appearance.
Window glass. Windows make up the majority of the vehicle as a whole, so using lightweight, low-density materials as windows is an important means of vehicle handling and weight reduction. Automotive windows have high requirements for light transmission, impact resistance, weather resistance and less debris. PMMA not only meets the above conditions, but also has the functions of anti-UV, anti-aging and weatherproof. Therefore, it is used by most European auto manufacturers as an auto window .Side and rear windshield materials can reduce the weight by 40-50% compared to traditional glass.
Dashboard: PMMA has very good toughness, the best toughness, high toughness, no cracking due to vibration resistance, no cracking after passing the voltage withstand test, good strength, good optical transparency, and no cracking when used as a tool. panel.
Bumper: PMMA and ABS composite materials can be used as bumpers for new energy vehicles. It combines the advantages of PMMA, scratch resistance, non-fading, environmental protection and ABS impact resistance, good temperature resistance, good electrical properties and light weight. spraying.At the same time, the cost is lower than magnesium aluminum alloy.
Analysis of future trends in PMMA development
PMMA not only has good mechanical strength and a certain chemical stability, but also excellent optical transparency, which makes it widely used in various fields. The current synthesis direction of polymethyl methacrylate is mainly focused on improving its heat resistance and processing fluidity, optimizing the PMMA process route, effectively improving its heat resistance and processing fluidity, providing product performance and cost advantages, and meeting market requirements.
In the future, the potential market demand for high-precision advanced PMMA products will increase, and research will also begin with the modification of PMMA. In short, with the development of science and technology, the application areas of PMMA will become wider and wider, so in-depth development and research on its synthesis and application areas is still very valuable.