Related Legal Terms & Definitions. 1  COMPETENT WITNESS One who is legally qualified to be heard to testify in a cause. 2  RESPECTABLE WITNESS One who is competent to testify in a court of justice. 3  CREDIBLE WITNESS A credible witness is one who is competent to give evidence, and is worthy ofâ¦.
In general, combustibility of polymers depends on their chemical structures. Polymers with more carbon atoms in their macromolecular structure (e.g., PE, PP, PS, PMMA) are more combustible than polymers containing halogen atoms (e.g., PVC, PVDC, PTFE).
It is also employed as a component of adhesives and emulsifiers, as a water-soluble protective film, and as a starting material for the preparation of other resins. By reaction with butyraldehyde (CH3CH2CH2CHO) and formaldehyde (CH2O), PVA can be made into the resins polyvinyl butyral (PVB) and polyvinyl formal (PVF).