Application Of Diatomite In Plastic Modification And Polyolefin Masterbatch

Diatomite is a kind of natural biological sedimentary with a large number of pores, which has many properties such as light-weight, high porosity, high surface free energy and strong adsorption etc. There are lots of mineral resources in china, but the effective utilization rate is low. Now the main application areas of diatomite are in aid, insulation materials and adsorbents. To developed the diatomite’s high value is significant by using the unique structure. In this paper, the application of diatomite have been studied in three ways. (1) polypropylene and polyamide-6 were selected to research the application prospect of diatomite as a kind of inorganic filler in plastic modification. (2) The value of diatomite in the field of intumescent flame retardant was studied. (3) Application of diatomite in the polyolefin masterbatch.The diatomite was been surface treatment by silane coupling agent. The heat distortion temperature of polypropylene was improved 25.6℃, when the content of diatomite is 20wt% in PP. Otherwise, the modulus and flexural strength of PP were increased significantly, the flexural modulus increased 68% and the strength increased 9%,when diatomite content is 30wt% in PP, but the impact strength was not improved, the processing performance of diatomite/PP composite.The mechanical properties of nylon was significantly improved by diatomite. The tensile strength increased 24%, flexural strength improved 33%, the elastic modulus added 96% and the flexural modulus increased 66% when the amount of diatomite is 25wt% in PA, the charpy notched impact strength improved 26% when the dosage is 5wt%. Meanwhile, diatomite reduced the maximum thermal decomposition rate and raised the heat distortion temperature of PA, the heat distortion temperature increased 15.3℃ when the dosage of celite is 20wt%.Flame retardant properties of PP are improved when diatomite as a kind of synergists in intumescent flame retardant (APP:PER=3:1), the oxygen index of IFR/PP material increase from 31% to 33.8% when diatomaceous earth is 2wt% in IFR, and the UL-94 lever always is V-0. Diatomite can promote the mechanical properties of IFR/PP composite.The tinting strength, coloring performance and dispersion of organic pigments was enhanced, when the diatomite replacement ratio is 10wt%～20wt%. and the hiding power is the same, the cost was reduced.