Plasticizers or dispersants are additives that increase the plasticity or fluidity of a material. The dominant applications are for plastics, especially polyvinyl chloride (PVC). Examples are- Trimethyl trimellitate (TMTM), Dioctyl adipate (DOA), Dibutyl sebacate (DBS), Tricresyl phosphate (TCP) etc. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The applications for epoxy-based materials are extensive and include coatings, adhesives and resin matrices for composite materials. Examples are- Bisphenol F epoxy resin (BPFER), Novolac epoxy resin (NER).
Hence, 1, 2 and 4 are the examples of plasticizers.