Synergistic formulations

Bracic, M., Perez, L., Martinez-Pardo, R.I., Kogej, K., Hribemik, S., Sauperl, O., Zemljic, L.F., 2014. A novel synergistic formulation between a cationic surfactant from lysine and hyaluronic acid as an antimicrobial coating for advanced cellulose materials. Cellulose 21 (4), 2647-2663. 

Melapur P46 is a synergistic formulation of nitrogen and phosphorus-containing compounds, developed for polyolefins, particularly polypropylene. 

Poly(vinyl chloride). PVC is a hard, brittle polymer that is self-extinguishing. In order to make PVC useful and more pHable, plasticizers (qv) are added. More often than not the plasticizers are flammable and make the formulation less flame resistant. Flammability increases as the plasticizer is increased and the relative amount of chlorine decreased, as shown in Table 7. The flame resistance of the poly(vinyl chloride) can be increased by the addition of an inorganic flame-retardant synergist. 

Olefin Polymers. The flame resistance of polyethylene can be increased by the addition of either a halogen synergist system or hydrated fillers. Similar flame-retarder packages are used for polypropylene (see Olefin polymers). Typical formulations of the halogen synergist type are shown in Table 15 the fiUer-type formulations are in Table 16. 

Cblorina.ted Pa.ra.ffins, The term chlotinated paraffins covers a variety of compositions. The prime variables are molecular weight of the starting paraffin and the chlorine content of the final product. Typical products contain from 12—24 carbons and from 40—70 wt % chlorine. Liquid chlotinated paraffins are used as plasticizers (qv) and flame retardants ia paint (qv) and PVC formulations. The soHd materials are used as additive flame retardants ia a variety of thermoplastics. In this use, they are combiaed with antimony oxide which acts as a synergist. Thermal stabilizers, such as those used ia PVC (see vinyl polymers), must be used to overcome the inherent thermal iastabiUty. 

Adhesives. High concentration (>10%) solutions of poly(ethylene oxide) exhibit wet tack properties that are used in several adhesive appHcations. The tackiness disappears when the polymer dries and this property can be successfully utilized in appHcations that require adhesion only in moist conditions. PEO is also known to form solution complexes with several phenoHc and phenoxy resins. Solution blends of PEO and phenoxy resins are known to exhibit synergistic effects, leading to high adhesion strength on aluminum surfaces. Adhesive formulations are available from the manufacturers. 

Ba(B02)2 H2O, used in flame retardant plastic formulations as a synergist for phosphoms or halogen compounds and as a partial or complete replacement for antimony oxide (see Flame RETARDANTS), is excellent as an afterglow suppressant. The low refractive index of results in greater... 

Acid acceptor. This is the main function of metal oxides in CR adhesive formulations. Upon age, small amounts of hydrochloric acid are released which may cause discolouration and substrate degradation. Magnesium oxide (4 phr) and zinc oxide (5 phr) act synergistically in the stabilization of solvent-borne polychloroprene adhesives against dehydrochlorination. 

For larger, more complex LPHW systems and for LP steam heating systems, silicates are seldom used alone but are formulated with nitrite or molybdate inhibitors to provide synergistic corrosion protection. 

Dibasic salts of dicyclopentadiene dicarboxylic acid are claimed to be active as corrosion inhibitors [444], Certain salts of fatty acids (metal soaps), together with benzotriazole, are claimed to give synergistic effects for corrosion in antifreeze-agent formulations [446]. 

FBAs applied in combination may show a synergistic effect. Synergism is, at present, only of commercial interest with polyester brighteners. This phenomenon is discussed further in section 11.10. Conversely, the presence of a trace impurity in an FBA formulation may greatly reduce its effectiveness. In industrial laboratories much time and effort is expended in developing processes to minimise the content of such impurities or even to eliminate them completely. 

---