Blends containing poly(hydroxybutyrate-co-12%-hydroxyvalerate) and thermoplastic starch

1995 ◽  
Vol 41 (13) ◽  
pp. 323-328 ◽  
Author(s):  
H. Verhoogt ◽  
N. St-Pierre ◽  
F. S. Truchon ◽  
B. A. Ramsay ◽  
B. D. Favis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Thermoplastic Starch ◽  
Starch Granules ◽  
Biodegradable Composites ◽  
Morphological Studies ◽  
Flexible Material ◽  
Starch Blends ◽  
Dispersed Phases ◽  
Two Phases

Poly(hydroxyalkanoates) form biodegradable composites when blended with starch granules but the mechanical properties are poor. Unlike starch granules, thermoplastic starch is a flexible material that can be reprocessed at elevated temperatures. Mixing thermoplastic starch with poly(hydroxybutyrate-co-12%-hydroxyvalerate) resulted in a true blend in which the starch phase was also deformed. Nevertheless, the blends were still brittle despite the presence of the flexible starch phase. Morphological studies showed that the shapes of the dispersed phases in these blends were irregular and that the sizes were large owing to a large difference in viscosity between the two phases in the melt and inadequate shear during processing. Thermal analysis of the blends and starting polymers showed no indication of any interaction between the two polymers. Even if there is no compatibility between the two phases, improved mechanical properties may be obtained by optimizing the blend morphology during processing.Key words: P(HB-co-12%-HV), thermoplastic starch, blends.

scholarly journals Study of the Preparation and Properties of TPS/PBSA/PLA Biodegradable Composites

2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Yuxuan Wang ◽  
Yuke Zhong ◽  
Qifeng Shi ◽  
Sen Guo
Keyword(s):  
Mechanical Properties ◽  
Heat Resistance ◽  
Thermoplastic Starch ◽  
Sem Analysis ◽  
Infrared Spectrometry ◽  
Fourier Transform Infrared Spectrometry ◽  
Melt Mixing ◽  
Two Phase ◽  
Biodegradable Composites ◽  
Phase Compatibility

Thermoplastic starch/butyl glycol ester copolymer/polylactic acid (TPS/PBSA/PLA) biodegradable composites were prepared by melt-mixing. The structure, microstructure, mechanical properties and heat resistance of the TPS/PBSA/PLA composites were studied by Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), tensile test and thermogravimetry tests, respectively. The results showed that PBSA or PLA could bind to TPS by hydrogen bonding. SEM analysis showed that the composite represents an excellent dispersion and satisfied two-phase compatibility when the PLA, TPS and PBSA blended by a mass ration of 10, 30, and 60. The mechanical properties and the heat resistance of TPS/PBSA/PLA composite were improved by adding PLA with content less than 10%, according to the testing results.

Mechanical Properties of Poly(lactic acid) / Thermoplastic Starch Blends Crosslinked by Gamma Radiation

2013 ◽  
Vol 781-784 ◽  
pp. 467-470 ◽  
Author(s):  
Siriruck Kalapakdee ◽  
Thirawudh Pongprayoon ◽  
Kasinee Hemvichian ◽  
Phiriyatorn Suwanmala ◽  
Wararat Kangsumrith
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Gamma Radiation ◽  
Crosslinking Agent ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Optimum Dose ◽  
Gel Fraction ◽  
Twin Screw ◽  
Starch Blends

This research aims to determine the influences of radiation-induced crosslinking on the mechanical properties of polymer blends between poly (lactic acid) (PLA) and thermoplastic starch (TPS). PLA and TPS were mixed at different ratios (90:10, 80:20, 70:30, 60:40) in the presence of a crosslinking agent using a twin screw extruder. The blends were compression molded into films. The film samples were irradiated by gamma radiation at different doses. Gel fraction was used to determine crosslinking efficiency. Results showed that gamma radiation was able to induce crosslinking for PLA/TPS blends. The gel fraction and mechanical properties decreased with increasing TPS content. The optimum ratio of PLA:TPS with the maximum gel fraction and mechanical properties was 90:10 and the optimum dose was 40 kGy by gamma radiation.

scholarly journals Effect of natural fibres on the mechanical properties of thermoplastic starch

2016 ◽  
Vol 30 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Tomasz Oniszczuk ◽  
Agnieszka Wójtowicz ◽  
Leszek Moácicki ◽  
Marcin Mitrus ◽  
Karol Kupryaniuk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Compression Strength ◽  
Potato Starch ◽  
Cellulose Fibre ◽  
Thermoplastic Starch ◽  
Maximum Force ◽  
Processing Unit ◽  
Starch Granules ◽  
Screw Speed

Abstract This paper presents the results covering the mechanical properties of thermoplastic potato starch granules with flax, cellulose fibre, and pine bark addition. A modified single screw extrusion-cooker TS-45 with L/D = 18 and an additional cooling section of the barrel was used as the processing unit. The establishment influence of the fibre addition, as well as the extrusion-cooker screw speed, on the mechanical properties of the thermoplastic starch granules was the main objective of the investigation. The maximum force during compression to 50% of the sample diameter, elastic modulus, and compression strength were evaluated. Significant differences were noted depending on the amount of fibre used, while only an insignificant influence of screw speed on the mechanical properties of the granulate was reported. An increased amount of fibres lowered the maximum force as well as the elastic modulus and compression strength of the thermoplastic starch granulates.

PLLA and cassava thermoplastic starch blends: crystalinity, mechanical properties, and UV degradation

2021 ◽  
Vol 28 (2) ◽  
Author(s):  
César López ◽  
Kiryl Medina ◽  
Rosa D´Ambrosio ◽  
Rose Mary Michell
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Starch ◽  
Uv Degradation ◽  
Starch Blends

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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