Abstract. Blends of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized with a lactic acid oligomer (OLA) added at three different concentrations (15, 20 and 30 wt% by weight), were prepared by an optimized extrusion process to improve the processability and mechanical properties of these biopolymers for flexible film manufacturing. Morphological, chemical, thermal, mechanical, barrier and migration properties were investigated and formulations with desired performance in eco-friendly films were selected. The efficiency of OLA as plasticizer for PLA_PHB blends was demonstrated by the significant decrease of their glass transition temperatures and a considerable improvement of their ductile properties. The measured improvements in the barrier properties are related to the higher crystallinity of the plasticized PLA_PHB blends, while the overall migration test underlined that all the proposed formulations maintained migration levels below admitted levels. The PLA_PHB blend with 30 wt% OLA was selected as the optimum formulation for food packaging, since it offered the best compromise between ductility and oxygen and water vapor barrier properties with practically no migration. Vol.9, No.7 (2015) 583-596 Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2015.55 * Corresponding author, e-mail: ilaria.armentano@unipg.it © BME-PT In contrast to the development of novel polymeric materials and new polymerization routes, blending is a relatively cheap and fast method to tailor the plastics properties. As a result, this approach may play a crucial role in increasing the competitiveness of biopolymers [2][3][4][5]. Poly(lactic acid) (PLA) thereby represents the most investigated aliphatic polyester for a wide range of applications, due to its biodegradability, renewability and excellent mechanical properties, good processability and low cost [6,7]. It is now produced on a large scale and used for various applications in different domains: packaging, medicine, agriculture and textiles. However, high brittleness, slow crystallization rate and low barrier properties of PLA compared to those of synthetic polymers strongly limit its applications in, for instance, food packaging [6]. Several strategies have been attempted for PLA to enhance its crystallization rate as well as to improve its barrier properties. Blending of PLA with other biopolymers or conventional synthetic polymers is one of the most effective methods to obtain new properties required for specific end-use applications [8,9]. For example, blending PLA with poly(hydroxybutyrate) (PHB), a highly crystalline biopolymer with high melting point and among the most studied polyhydroxyalkanoates (PHAs), leads to materials with interesting physical, thermal, and mechanical properties compared to neat PLA [10][11][12]. PLA and PHB are biodegradable polyesters and they are used in consumer products by several industrial sectors due to their biocompatibility, biodegradability and sustainability [6,12,13]. They have comparab...

14Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized 15 with an oligomer of the lactic acid (OLA) were used as supporting matrices for an antibacterial

is below 2 from 8.2 GHz to 14.5 GHz. It is shown that the frequency band is very broader. Figure 3 demonstrates the magnitude distribution of electric field on the radiation patch. It is found that the grooves play an important role in the impedance matching. The grooves also largely affect the HPBW over the whole frequency band. Simultaneously, side curve edges also heavily affect the HPBW.The measured radiation patterns (E-plane and H-plane) are shown in Figures 4-6. It is shown that the HPBW of pattern at 8.4 GHz achieves 118°in E-plane, and 111°in H-plane. At the frequencies of 10.5 GHz and 12.6 GHz, the HPBW of E-plane are 119°and 114°, respectively. Both the HPBWs are 120°in the H-planes. The measured results show that this new antenna possesses the steady HPBW performance from 8.4 GHz to 12.6 GHz. It is verified that proposed antenna has good performance for wide scan phased array. CONCLUSIONA compact size linearly tapered slot antenna has been successfully investigated. Measured results show that the proposed antenna is with wider frequency band. Its half-power beamwidths are broader over the whole frequency band. ABSTRACT: In this article, g /2 open stub bandpass filters with flexible narrow bandwidth on duroid substrate are presented. This filters show flexible bandwidth with variation of the position of the open stubs using the external quality factor, Q e without changing the impedance value at microwave range. On the other hand, by replacing the series quarter-wavelength connecting-lines with the equivalent T-shaped line, a compact stub bandpass filter with second harmonic suppression can be obtained. This filter shows the insertion loss of 1.2 dB and the return loss of 21.9 dB at the center frequency of 5.8 GHz.Figure 6 Narrow-bandwidth BPF with g /2 open stubs and FBW of 10%. (a) The flexible BPF for narrow bandwidth. (b) The new type of BPF for the second harmonic suppression. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

This article proposed a new high‐QL resonator with a combination of a double spiral resonator and single split ring resonator with μ‐ near zero metamaterial.It is applied to the design of an X‐band oscillator. A very low phase noise for the oscillator can be obtained due to its sharp band‐ rejection characteristic of the new resonator. The oscillator is designed to operate at 9.2 GHz using the new resonator. Experimental results show the output power is 14.13 dBm, the second harmonic suppression is −46.33 dBc, and the phase noise is −104.54 dBc/Hz at 100‐kHz offset. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1577–1582, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26867

article and the utilization of this technique for developing, narrowband, CPW-based band-pass filters was demonstrated. Using this new filter topology, the task of designing higher order, narrowband, band-pass filters is simplified to the design and optimization of the second-order unit cell proposed in this article. Several fabricated prototypes of the proposed filter were presented to verify the principles of operation and the proposed design guidelines. Design simplicity, flexibility, and harmonic rejection are among the main advantages of the proposed filter topology. REFERENCES