We have already unknowingly entered the "plastic age" unprecedented in history. This kind of major and rapid change in humans mainly originated from the development of the petrochemical industry.
The ever-changing polymer chemical process
Plastic materials are the result of the division and integration of the chemical industry. First, the petrochemical industry process of cracking, separating, purifying and manufacturing various monomer raw materials from crude oil and light oil, and then through chemical synthesis and material processing skills to promote, develop and manufacture various plastic products It is not only light and durable but also inexpensive and has become a part of human life; the habit of applying plastic materials to humans has increased the requirements for the application of plastic materials with the improvement of living standards. The annual demand has continued to increase.
With the development of polymer chemical processes, successively invented the use of different monomer materials to manufacture diverse synthetic polymer materials, such as elastomers (commonly known as rubber), fibers (Fiber), plastics (Plastics) and other categories, each high Molecular materials, each with unique properties; blending two or more materials to produce a new material with another multiplier property, this is the mystery of polymer chemical processes, such as ABS Engineering Plastics Fiber-reinforced plastics (FRP) and rubber blended with complex (such as carbon black, white smoke, plasticizers, stabilizers, antioxidants, cross-linking agents, etc.), after professional processing procedures, respond to Special characteristics and needs.
As for the general-purpose plastic materials, although the monomer raw materials are simple, the ever-changing polymerization conditions and monomer raw material combinations can produce similar materials with various properties, such as polyethylene (PE) diversified products. Although understanding the ins and outs of plastic materials is definitely a professional area, but plastic products and human beings have almost reached the point where people walk with each other. Everyone needs to at least understand the true appearance of plastic products around life. This is the basic common sense of modern people.
Understand the plastic materials commonly used in life
There are many kinds of plastic materials commonly used at present; the top four are counted from the total amount of plastic produced in the world, and are sorted by usage: first, polyethylene (Polyethylene, referred to as PE), second, polypropylene (Polypropylene, referred to as short) PP), third, polyvinyl chloride (Polyvinyl chloride, PVC), fourth, polystyrene (Polystyrene, PS) and other four plastics, commonly known as Universal Plastics (Universal Plastics). However, China's output is the world's leading (first or second) polyethylene terephthalate (Polyethylene terephthalate, referred to as PET), that is, almost every household in China will use PET plastic (bottle or polyester Transparent film) and polyester fiber. These five types of plastics are linear organic materials with high molecular weights (10,000 or more than tens of thousands of units), and all have thermoplastic properties, so they are all called "thermoplastics".
These plastic materials are solid at room temperature. They are softened or melted by heat during processing and can be injected underflow and pressure. After cooling, they are molded solids. This "thermoplastic plastic" product side material or waste can be recycled and processed repeatedly. The "thermoplastic" products on the market are branded with the international general plastic number with numbers, indicating that it is available for recycling material classification:
Because of its stiffness, excellent toughness, lightweight (only 1/9 ~ 1/15 of the glass bottle), crash resistance, good chemical stability, easy to carry, low energy consumption during production, it is a cheap container The amount of consumption has almost reached the stage of being abused. Fortunately, there is a recycling channel of an original volunteer group in Taiwan, which successfully recycles the discarded "Battle Bottle", and recycles the "Battle Bottle" through domestic synthetic fiber factories. , Manufacture PET fiber (the same chemical composition, but a lower molecular weight polyester fiber), and successfully promoted the application of textile products, won the recognition of the international community. Recently, the PET material of "Bottle" has also been used in building materials. The popular museum "Far East Ark of Life" in the International Flower Expo held in Taipei from 2010 to 2011 is an alternative application of "Bottle" in the history of world architecture.
Only PVC needs plasticizer
The five major plastic materials, except for PVC, are all pure polymer materials. The application of its true properties requires no additives. Only PVC needs to add any additives, such as the amount of plasticizer (about 5 ~ 30%) to adjust the use of different hardness, add stabilizer to prolong the service life, etc.
There are many types of plasticizers added in the PVC process, commonly known as DOP in the industry, mainly like i-2-Ethylhexyl phthalate (DEHP for short), some items made of flexible PVC synthetic leather, such as brand new sofas, shoes, We often smell a strong plastic smell in leather bags or raincoats. In fact, this is the smell of the plasticizer DEHP.
PVC has the advantages of other plastic materials, so PVC is now the most widely used. However, the existing PVC finished products are plastic products processed through complex formulations (plasticizers, stabilizers, inorganic additives, pigments, etc.). However, the blending of these additives does not have any chemical bonding, and it is easy to migrate to the product. On the surface, you should pay special attention to the toxicity of DEHP plasticizer; although it is impossible to measure whether the dissolution amount of plasticizer will exceed the "tolerable daily intake" (Tolerable Daily Intake), so plastics containing DEHP plasticizer must not be used with food Or long-term human contact.
After use, PVC cannot be recycled and reused directly. In addition to the organic chlorine (Organochlorine) contained in the material, the high-temperature (incineration) treatment of PVC will produce highly toxic dioxin (2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (dioxin for short) has been proven to cause health hazards to organisms. In recent years, countries have gradually restricted the application of polymer materials containing organic chlorine (PVC, closing rubber, chlorinated wax, and other materials containing organic chlorine).
The plasticizer contained in soft PVC will gradually dissipate into the air or dissolve into groundwater or rivers with the use of the product, especially the waste PVC products. The plasticizer DEHP is a kind of environmental hormone. If it accumulates too much, it will cause environmental harm. If it exceeds the "Tolerable Daily Intake" (Tolerable Daily Intake), it will also cause damage to contact organisms, which is also the current society. The most concerning issue.
Matters needing attention when using plastic
The above five commonly used plastic materials, although they are easy to use, durable, versatile, cheap and good, are quite worthy of being cherished; please also remind the public to avoid misuse of plastic materials, causing danger and causing environmental damage, because of their shortcomings Change should pay special attention, for example:
1. Thermoplastics with a low melting point are easily deformed or melted by heat (except HDPE and PP can be sterilized by steam) and should be avoided in high temperature (above 80 ℃) environment.
2. Flammable organic materials must never be in direct contact with the fire source and are extremely flammable. (PVC is a flame-retardant material). It will ignite and burn when exposed to high heat, producing a large amount of black smoke (carbonized gas), especially PVC Dioxin is highly toxic.
3. Avoid contact with organic solvents (PET, PS, PVC, and other solvents soluble in acetone, toluene, etc.) or grease, etc. They are all linear (uncrosslinked) organic polymers, and there may be smaller molecular materials Will be dissolved.
Taiwan's plastic material technology is already a leading international power. Although Taiwan does not have petroleum resources, it has a stable source of plastic material raw materials and product application technology, especially the development of cross-domain material application technology. We have a unique environment and competition to develop new products. Advantage. Enjoy high-quality and low-cost plastic products in the "plastic age" in the 21st century.