Why are acrylics not spun from the metal ??
what are thermoplastics and thermosetting plastics ??
To what use can propylene and acetylene be put. ??
Answer these in one word... please no irrelevant answers please Note only for class 8
Answers
Answer:
★ Acrylics are so named because they are made from polymer polyacrylonitrile. They are not spun from the melt because these polymers decompose without melting. Thus, they are dissolved in a specific solvent and the solution is forced through spinnerets to obtain filaments that are spun into yarns.
★ Thermoplastics : It is synthesized by the process called addition polymerization. It is processed by injection moulding, extrusion process, blow moulding, thermoforming process, and rotational moulding. They have secondary bonds between molecular chains. They have low melting points and low tensile strength. It is lower in molecular weight, compared to thermosetting plastic.
Thermosetting Plastic : They are synthesized by condensation polymerization. It is processed by compression moulding, reaction injection moulding. They have primary bonds between molecular chains and held together by strong cross-links. They have high melting points and tensile strength. It is high in molecular weight.
★ Propylene - Propylene is an attractive alternative to propane for heating and cutting due to its superior combustion performance. It is also widely used as a fuel gas for high-velocity oxygen fuel (HVOF) processes. In addition, the chemical and plastics industries rely on propylene as a fuel gas.
Acetylene - Acetylene is used for welding and cutting. The welding process that uses acetylene is known as oxy-fuel cutting or gas cutting. This method is used to cut or weld materials that require temperatures as high as 3,500 °C (6,330 °F). Among all other gases, acetylene is capable of producing the hottest flame.
HOPE IT HELPS U MY FRND !!!