Addition Of Acetyl Tributyl Citrate Research Articles

Preparation and slow-release performance of modified poly (butyleneadipate-co-terephthalate) melt-coated urea pellets

The current use of environmentally friendly slow-release fertilizers in agriculture is important for solving mitigating environmental pollution caused by the low utilization of fertilizers. In this study, modified biodegradable poly (butyleneadipate-co-terephthalate) (PBAT) based melt coated slow-release urea is prepared, avoiding the use of organic solvents. PBAT is modified with titanium tris(dodecylbenzenesulfonate) isopropoxide (TDBSP), which reduces the molecular weight and crystallinity. The addition of acetyl tributyl citrate (ATBC) as a plasticizer further improves the flowability of the material to satisfy the requirements of melt-coated urea. The ability of TDBSP to affect crystallization and result in branched behaviors in PBAT is demonstrated via differential scanning calorimetry (DSC) and rheological studies. The PBAT coating material is prepared by adding 1 % w/w of TDBSP and 35 % w/w of ATBC (% w/w dry PBAT basis), which constitutes 18 % of the urea mass by weight when coated. Scanning electron microscopy results show that the coating material exhibits the best coating effect on urea pellets. Results of the soil column leaching test show the slow-release performance of the coated area as well as the release of nutrients from the coated urea of 80.09 % after 28 d. By applying a single application of coated slow-release fertilizer in tobacco plant cultivation, the growth data of the tobacco plant is better than that of a topdressing applied after 30 d in conventional cultivation (under the same amount of fertilizer application), while labor cost is saved.

On the Use of Paper Sludge as Filler in Biocomposites for Injection Moulding.

The potential use of paper sludge (PS) as filler in the production of bio-composites based on poly lactic acid (PLA) and polybutylene adipate terephthalate (PBAT) was investigated. PS/PLA/PBAT composites, with addition of acetyl tributyl citrate (ATBC) as biobased plasticizer, were produced with PS loadings up to 30 wt.% by twin-screw extrusion followed by injection moulding. The composites were characterized by rheological measurements, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and mechanical tests (tensile and impact resistance) to study the effect of PS on the processability, thermal stability, crystallinity and mechanical performance of polymeric matrix. The optimized composites at higher PS content were successfully processed to produce pots for horticulture and, in view of this application, preliminary phytotoxicity tests were conducted using the germination test on Lepidium sativum L. seeds. Results revealed that developed composites up to 30 wt.% PS had good processability by extrusion and injection moulding showing that PS is a potential substitute of calcium carbonate as filler in the production of bio-composites, and the absence of phytotoxic effects showed the possibility of their use in the production of pots/items for applications in floriculture and/or horticulture.

Properties and Degradation of Novel Fully Biodegradable PLA/PHB Blends Filled with Keratin.

The utilization of keratin waste in new materials formulations can prevent its environmental disposal problem. Here, novel composites based on biodegradable blends consisting of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB), and filled with hydrolyzed keratin with loading from 1 to 20 wt % were prepared and their properties were investigated. Mechanical and viscoelastic properties were characterized by tensile test, dynamic mechanical thermal analysis (DMTA) and rheology measurements. The addition of acetyltributyl citrate (ATBC) significantly affected the mechanical properties of the materials. It was found that the filled PLA/PHB/ATBC composite at the highest keratin loading exhibited similar shear moduli compared to the un-plasticized blend as a result of the much stronger interactions between the keratin and polymer matrix compared to composites with lower keratin content. The differences in dynamic moduli for PLA/PHB/ATBC blend filled with keratin depended extensively on the keratin content while loss the factor values progressively decreased with keratin loading. Softening interactions between the keratin and polymer matrix resulted in lower glass transitions temperature and reduced polymer chain mobility. The addition of keratin did not affect the extent of degradation of the PLA/PHB blend during melt blending. Fast hydrolysis at 60 °C was observed for composites with all keratin loadings. The developed keratin-based composites possess properties comparable to commonly used thermoplastics applicable for example as packaging materials.

Endowing piezoelectric and anti-fouling properties by directly poling β-phase PVDF membranes with green diluents

Membrane fouling can be efficiently mitigated by the vibration of the piezoelectric membrane stimulated by AC signals, but it is still a challenge to fabricate piezoelectric membranes with great efficiency, low energy-consumption, and no harm to the environment during its preparation. The present work provides a new approach to poly(vinylidene fluoride) (PVDF) membranes with piezoelectric properties by directly poling β-phase PVDF membranes using green diluents, which revealed better piezoelectric properties than poling α-phase PVDF membranes. Basically, absolute β-phase crystals of PVDF membranes were induced over thermally induced phase separation with the addition of Acetyl tributyl citrate (ATBC)/ionic liquid ([BMIM]PF6), which are regarded as green and environment-friendly diluents. To endow the piezoelectric property to the β-phase PVDF membrane, a poling process was necessarily conducted. The effect of the poling process on the membrane structure, morphologies, properties, and performances was investigated. Meanwhile, a vibration test for both of the poled and unpoled membranes was performed in an excitation of the alternating signal. The results demonstrated that the poling process positively endowed the piezoelectric property to the PVDF membranes. The membrane structure, morphologies, and performances of the membranes were also changed to some extent by the poling process. Additionally, filtrations of the poled membrane both with and without electrical signals were carried out to test their antifouling performance on the CaCO3 suspension system and BSA solution, respectively. It was observed that the stable flux of the membranes notably improved when subjected to an electrical AC signal. Thus, it depicted that the piezoelectric PVDF membrane directly poled from the β-phase possesses a promising antifouling performance due to its high piezoelectric vibration.

Blending and plasticising effects on the behaviour of poly(lactic acid)/poly(ε-caprolactone)

Polymer blending is one of the most convenient methods to be used to overcome the limitations of some single properties of polymers and to achieve the combinations required for specific applications. Another feasible common practice is the incorporation of additives of low molecular weight such as plasticisers to impart flexibility, improve toughness and lower the glass transition temperature ( Tg). This study focused on the effects of blending and plasticising on the crystallisation behaviour of poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL). PCL with longer degradation time compared with other polymers was blended with PLA to overcome the limitation of its brittleness and poor thermal stability. Acetyl tributyl citrate (ATBC) and acetyl triethyl citrate (TEC) were used as plasticiser in PLA/PCL blends. The rigid and plasticised blends at various ratios were analysed by differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. The results revealed a slight increase in the degree of crystallinity and a significant increase in the Tg of PLA due to the addition of PCL. The addition of ATBC has promoted a decrease in thermal stability of the blends. The slight increase in the degree of crystallinity suggested that PCL acted as a nucleating agent. The citrate plasticisers were shown to lower the Tg and have much more enhanced the crystallisation of PLA. Moreover, the rigid and plasticised blends were shown to be partially miscible.

Efficient preparation of poly(lactic acid) nanofibers by melt differential electrospinning with addition of acetyl tributyl citrate

ABSTRACTPoly(lactic acid) (PLA) nanofibers, as a biodegradable and environmentally friendly material, have potential applications such as biological medicine, efficient filter material, and so on. PLA nanofibers are usually prepared by solution electrospinning method with toxic solvents, such as chloroform, chloromethane, and N,N‐dimethyl formamide. In this work, PLA nanofibers were fabricated with a self‐designed melt differential electrospinning device, assisted by addition of nontoxic acetyl tributyl citrate (ATBC) and by airflow. Molecular dynamics simulations were performed to understand the experimental results. The results revealed that the fiber diameter decreased with increasing airflow velocity, and fibers with a diameter as small as 236 nm were obtained at the highest airflow velocity of 25 m/s (with 6 wt % of ATBC). Furthermore, a significantly accelerated falling speed of the jets of about 347 times of that without airflow was achieved at a flow rate of 25 m/s. These results demonstrated that the combination of adding ATBC and airflow assistance was a good strategy to achieve finer fibers with improved stability and efficiency, making it a promising way for mass green production of PLA nanofibers. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46554.

Effects of co‐plasticization of acetyl tributyl citrate and glycerol on the properties of starch/PVA films

ABSTRACTStarch/polyvinyl alcohol (PVA) nanocomposite films by film blowing process were successfully obtained. Starch (1700 g), PVA (300 g), and organically modified montmorillonite (OMMT, 200 g) were blended and plasticized with acetyl tributyl citrate (ATBC) and glycerol (GLY) at weight ratios of 0/100, 5/95, 10/90, 15/85, 20/80, and 25/75. The structural, morphology, barrier, mechanical, and thermal properties of the films, as well as molecular interactions in the nanocomposites were analyzed. The 3.98 nm d‐spacing was the highest in starch/PVA nanocomposite films plasticized with ATBC/GLY ratio of 10/90. The film with ATBC/GLY (5/95) had the lowest WVP (3.01 × 10−10 g m−1 s−1 Pa−1). The longitudinal tensile strength (TS) of starch/PVA nanocomposite films gradually increased from 4.46 to 6.81 MPa with the increase of ATBC/GLY ratios. The Tg steadily increased from 49.2°C to 55.2°C and the ΔH of the nanocomposite films decreased from 81.77 to 51.43 J/g at the presence of ATBC. The addition of ATBC into GLY plasticized starch/PVA/OMMT system enhanced the intermolecular interaction in the nanocomposites. This study proved that ATBC was an excellent compatibilizer in the preparation of starch/PVA/OMMT nanocomposite films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42544.

Polylactides with “green” plasticizers: Influence of isomer composition

ABSTRACTSynthesized polylactides (PLA) with different D‐isomer contents in the polymer chain were melt‐blended with a series of “green” plasticizers by extrusion. Mechanical and thermal properties as well as the morphology of the plasticized materials were characterized to demonstrate how the combination of PLA with different D‐contents and plasticizer controls the material properties. After addition of acetyl tributyl citrate (ATC), the elongation at break for PLA with a low D‐isomer content was twice as high as that for PLAs with high D‐isomer contents. Similar variations in the plasticization effect on the PLAs were also observed with the other plasticizers used, glyceryl triacetate (GTA), glycerol trihexanoate (GTH) and polyethylene glycol (PEG). In order to continue with the development of renewable polymers in packaging applications, the interrelation between a plasticizer and a specific polymer needs to be understood. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2962–2970, 2013

Isothermal Cold‐Crystallization of PLA/PBAT Blends With and Without the Addition of Acetyl Tributyl Citrate

AbstractThe isothermal cold‐crystallization kinetics of the PLA phase is studied by DSC and the crystallization from the melt by PLOM. Even though the blends exhibit two phases by SEM, several pieces of evidence indicate that partial miscibility may be present in these blends: small changes in both Tg and Tm of the PLA phase; a dependence of the spherulitic growth rate on blend composition and the oclusion of PBAT droplets inside PLA spherulites. Acetyl tributyl citrate is able to plasticize both phases in the blends, but it displays a preference to dissolve within the PBAT rich phase. There is a synergystic effect on the increase in the overall crystallization rate of the PLA rich phase when both ATBC and PBAT are present in the blend.