Get together lactic acid (PLA) is a kind by but the polymer that second birth biology makes character; It is barmy plant starch normally, be like corn, sugar cane, cassava or beet. In use, it shows the machinery that derives polymer likeness with certain oil and physical character, but it is but the —— of biology degradation falls in commercial compost condition, PLA will be in 12 decompose inside week, and get together to benzene glycol of 2 formic acid ester (PET) needs a few centuries. Apply extensively at biology medicine and spin industry, in recent years it packed the welcome degree of the domain to have tremendous growth in food. However, PLA is regarded as “ temporarily ” solution. During suiting a festival very much outside sell coffee cup and rubber packing sheet, but because its cut off,function is differred (to vapor and oxygen osmotic tall) , because this suits far from,store for a long time food. To resolve this one restriction, a when come from Chile interdisciplinary research group developed a series of PLA accept rice composite material, will but the polymer of biology degradation and function change Xi of oxidation black lead (GO) photograph is united in wedlock. Their research achievement is published in " Polymer Testing " in July on print.
They produce Xi of oxidation black lead above all, the ——25°C below the temperature that differs in two kinds next (GO-DA1 and GO-ODA1) with 80°C (GO-DA2 and GO-ODA2) —— uses two sort model alkyl amine (amine of the last of the ten Heavenly Stems (DA) and 18 amine (ODA) ) undertake to its the function is changed. Use melt mixes a technology, the filling of grain of GO accept rice that changes these functions with different load capacity (0.2, 0.7, 2 Wt% ) mix into enters PLA in. The compound and filmy ply of preparation is 1 millimeter (use at mechanical test) or 0.1 millimeter (use at permeability to analyse) , experienced a series of other token level, include FTIR spectrum, hot serious analysis and difference to show scanning to measure hot way.
The X ray diffraction of black lead, GO, GO-ODA1, GO-ODA2, GO-DA1 and GO-DA2 pursues.
The reaction that they discover to temperature changes function of black lead Xi to change level to distinct effect —— undertakes below 80 °C to oxygen is shown leave higher quality yield than room temperature. Ultimate analysis makes clear, the function is changed in adding nitrogen accept rice grain, the biggest content that achieves GO-DA2 (3.92 Wt% ) . X ray diffraction and FTIR support this one discovery, confirmed the function turns chain of alkyl of the existence on accept rice particle. The heat of accept rice grain analyses discovery, although Xi of oxidation black lead is in 130 to the quality loss that showing is shown between 280 °C (38%) , but the thermal stability that the function changes Xi of oxidation black lead should get much —— high for example, the quality loss of GO-DA2 is only 12% , the quality loss of GO-ODA2 is 7% only. The curve measuring heat of compound film makes clear, the crystallization of PLA-GO spends the GO filmy —— that changes under any PLA functions this shows the function changes the polymer that promoted composite material and its filling between taller affinity. The optical microscope analysis of composite material confirmed this one result.
Consider to discover, as the addition of load capacity of accept rice grain, the mechanical function of PLA composite material drops somewhat. They this ascribe 4 elements, “…… reunites composite material crystallization spends rice of the formation of body, accept reduce, grain - the action adding model of the alkyl catenary that exists in the formation of polymer interface break and Xi of modified oxidation black lead. ” cuts off the test makes clear, as the addition of load capacity of accept rice grain, of the oxygen of composite material and vapor osmotic reduce significantly. Composite material PLA-GO-ODA2 shows first-rate whole to cut off function —— is when 0.7wt% , photograph comparing of the rate that appear oxygen and standard PLA was reduced 30.4% . Compare with photograph of alone use PLA, the GO-ODA2 that uses 0.2 Wt% only can make vapor permeability is reduced 50.2% .
Besides the “ application besides other possibility, this kind cuts off improve of function significantly make this kind of material applies to food to pack. ”
Article origin: Materialstoday