The Application Of Natural Mineral Attapulgite In Polymer Materials And Luminescent Materials

With the goal for the application of attapulgite in polymer composites and luminous materials,this dissertation optimized the purification and modification technologies of the attapulgite raw material.Then,the natural rubber/attapulgite and nitrile butadiene rubber/attapulgite/hydrotalcite nanocomposites were prepared.Additionally,yellow phosphor was synthesized by using the attapulgite as the matrix materials.It provided a new way for the application of attapulgite in white LED materials.Furthermore,the preparation technology of the nitrile butadiene rubber/attapulgite nanocomposite was improved based on the existing research work in our group,while perfected the nanocomposite from small to pilot a larger version of the experiments.It laid a foundation for the future industrialized production and commercialization application of the NBR/attapulgite nanocomposite.The main content of the paper and the experimental results are as follows:1.In order to determine its physical properties,such as components,morphology and particle size distribution,the raw materials of attapulgite were analysized.A purification scheme was made due to its impurity composition.By the screening of modification agent,dispersant,centrifugal slurry concentration and centrifugal conditions optimization,the optimum purification conditions were determined from the tests.The results showed that the attapulgite performanced improvement and clarity crystallizations had more uniform particle size distribution and particle morphology after purification treatment,which created good conditions for the application of the follow-up.2.Without any destruction on the unique fiber structure of attapulgite,the surface of attapulgite had been modified by carbon coatings.Then,we synthesized a natural rubber/attapulgite composite by a change in the polarity of the surface.The results showed that the mechanical properties of natural rubber,such as tensile strength,tear strength,et al.,were improved,if the carbonized attapulgite was added.Moreover,the composites materials with excellent mechanical properties could be prepared even with a large amount of filler.At the same time,the SEM images indicated that the sizes of carbonized attapulgite reached nanoscale and dispersed well in rubber matrix,implying the as-synthesized natural rubber/attapulgite composite material was a kind of nanometer composite material.3.Layered hydrotalcite was synthesized in the attapulgite clay aqueous solution which was through purification processing.Subsequently,the attapulgite(ATP)/hydrotalcite(LDH)/nitrile butadiene rubber(NBR)nanocomposites were prepared by emulsion intercalation.The structure of the nanocomposites was characterized by XRD and SEM.The effect of attapulgite/hydrotalcite composites on the mechanical properties was investigated.XRD and SEM confirmed that rubber chains were intercalated into the attapulgite/hydrotalcite composites.In addition,fuzzy junction surface of clay mineral and rubber matrix shows that ATP/LDH has good compatibility with NBR.When the attapulgite/hydrotalcite composites content were lower than 15 mass%,the nanocomposites showed excellent mechanical properties.Furthermore,the hybrid fillers have better reinforcing effect than individual fillers due to the strong physical interaction of the dual filler networking.4.By purification and acid treatment,the natural mineral attapulgite was used as the raw material of Si,Al,and applied to the preparation of fluorescent material for the first time.The yellow phosphor of Sr2.965Al0.08Si0.92O5:0.025Ce3+,0.01Eu2+ single phase was synthesized in a wide temperature range.In this work,we solved the problems,such as the single Sr3SiO5 phase is obtained difficultly,and the appearance of the second phase in the process of synthesis.The as-synthesized Sr2.965Al0.08Si0.92O5:0.025Ce3+,0.01Eu2+ exhibited an emission range of 450?750nm and the emission peak at 561nm,namely a potentially yellow phosphor for white LED.5.With purified attapulgite as raw material and by optimizing the existing technologies of our laboratory,the NBR/attapulgite nanocomposite was prepared using the emulsion of flocculants.The cooperative enterprise technical personnel had been carried on the preliminary test after it was verified by laboratory,and the good effect has been obtained.Based on them,the pilot enlarge test was finished by the use of the cooperative enterprise industrial production equipment.The test results showed that the production was a new type of nitrile rubber with good mechanical properties,its performances reached the optimal level of nitrile rubber factory,which laid a strong foundation for industrialized production and commercialization and application in the future.