first its available and relativity cheap, is very hard and resists impact distortion very well relative to other plastics and its very dense and thus, has a good tensile strength, has a very good resistant to alkalis and chemicals. Other way the disadvantages of PVC are its very poor heat stability. For this that additives, which stabilize the material at very high temperatures are naturally additional to the material during production, also its produces toxic fumes when melted and/or subject to a fire