Silicone products:
Silicone material is mainly a compound composed of organic silicon and silicon atoms combined with each other. The main material is siloxane, which is also the most used and most connected type of silicon chain compound. The material is insoluble in fusion substances and does not mix with any Substances react in conflict and can be left standing under any environmental conditions. The raw materials of silicone rubber products are mainly composed of silicone oil, siloxane, silicone resin and silane coupling agent. They are currently the safest and most environmentally friendly type in the rubber and plastics industry. Chemical materials.
During use, silicone has excellent adaptability to the environment. Compared with PVC thermoplastic materials, what stands out is its environmental adaptability. It can be used for a long time in high and low temperatures and in various environments without affecting the service life. There are many types of fixed-line molded silicone products. , outstanding performance, common standard performances are as follows:
Temperature resistance:
It can achieve good temperature resistance characteristics, and the conventional temperature resistance range is within -40~230 degrees for long-term use.
Environmental adaptability:
It has good climate resistance and is not easily oxidized by ultraviolet rays and ozone environments. It can be used normally in natural environments.
Physiological inertia:
Participating silicone compounds are some of the most inactive compounds known. They are very resistant to biological aging, have no rejection reaction with animal bodies, have good anticoagulant properties, and can be used in a variety of environments.
Stretch strength:
The finished silicone product has good tensile strength. The main silane chain in the silicon molecule is relatively fine and flexible, so it has strong tensile resilience and can stretch and rebound for a long time without deformation.
Insulating properties:
Silicone products have good electrical insulation properties. Its dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistivity and surface resistivity are among the best among insulating materials, so it is a relatively stable electrical material. one!
PVC products:
The full name of PVC products is polyvinyl chloride. It is mainly a polymer polymerized by the compound vinyl chloride monomer and azo compounds and other chemical additives under the action of high temperature. PVC materials can be synthesized into different types of products through polymer synthesis. PVC gifts and silicone gifts are both relatively common gifts in the market today. PVC material is mainly a white powdery amorphous substance with a density of about 1.3-1.5. The vitrification of the material is within 90 degrees, and the maximum temperature resistance is 170 degrees. The temperature resistance effect is low, and it will automatically decompose into hydrogen chloride under high temperature conditions, and it will automatically decompose catalytically if it exceeds the temperature resistance range.
Conventional identification methods of PVC are generally summarized into the following three categories, namely:
(1) Combustion method identification:
Softening or melting temperature range: 75~90°C;
Combustion situation: self-extinguishing after ignition;
Combustion flame state: yellow above and green below, smoke; condition after leaving the fire: extinguished after leaving the fire; odor: pungent sour smell.
This method is the simplest and most direct, and is generally the first choice.
(2) Solvent treatment identification:
Solvent: tetrahydrofuran, cyclohexanone, methanone, dimethylformamide;
Non-solvents: methanol, acetone, heptane.
Determine whether it is PVC by adding the suspected PVC plastic to the above solvent and observing the dissolution of the plastic. After the solvent is heated, the dissolution effect will be more obvious.
It is almost difficult to identify the difference between PVC products and silicone products in the hands of consumers. There are several outstanding points:
1. Texture
There is a big difference between silicone and PVC. Silicone material will have a good fleshy feeling when touched by hand, and will not appear old-fashioned. Moreover, the fineness of the material is better than that of PVC material, while the texture of PVC will be slightly rough. Not as soft and smooth as silicone.
2. Color
There is basically no difference in color between newly produced silicone products and PVC products. However, after long-term use, PVC materials will appear sticky, discolored and yellowing over time, especially in light and heat environments, while silicone materials rarely This kind of situation occurs, but some materials also appear yellowing.
3. Hardness
In terms of hardness, the hardness of silicone can be between 30-90, while the conventional hardness of PVC is between 50-95. Relatively speaking, the hardness of silicone materials can be lower and softer, while PVC materials cannot reach the hardness of silicone. The difference in softness and hardness is that silicone is hard and has good resilience, while PVC has poor resilience.
4. Temperature
The difference in temperature effect is that the silicone material has a better effect. The processing temperature of silicone rubber processing manufacturers during the production process is about 180 degrees. The normal temperature resistance effect is about -40 to 230 degrees, while the softening or melting temperature range of PVC is: 75 ~90 degrees or so, certain chemical reactions will occur when the temperature exceeds 90 degrees. Silicone will turn white and burn, and PVC will soften and go out in flames; odor: pungent sour smell.
5. Rebound
In terms of products, the resilience is the most important difference between the two materials. The silicone material has relatively good resilience due to its good silicon molecular connection strength, while the PVC material has greater polydispersity. The rebound effect is naturally not as outstanding as that of silicone materials.
