Characterization of citric acid/glycerol co-plasticized thermoplastic starch prepared by melt blending

2007 ◽  
Vol 69 (4) ◽  
pp. 748-755 ◽  
Author(s):  
Rui Shi ◽  
Zizheng Zhang ◽  
Quanyong Liu ◽  
Yanming Han ◽  
Liqun Zhang ◽  
...  
Keyword(s):  
Citric Acid ◽  
Thermoplastic Starch ◽  
Melt Blending

scholarly journals Ductility and Toughness Improvement of Injection-Molded Compostable Pieces of Polylactide by Melt Blending with Poly(ε-caprolactone) and Thermoplastic Starch

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2138 ◽  
Author(s):  
Luis Quiles-Carrillo ◽  
Nestor Montanes ◽  
Fede Pineiro ◽  
Amparo Jorda-Vilaplana ◽  
Sergio Torres-Giner
Keyword(s):  
Mechanical Performance ◽  
Thermoplastic Starch ◽  
Thermomechanical Properties ◽  
Ternary Blend ◽  
Melt Blending ◽  
Plastic Materials ◽  
Twin Screw ◽  
Spherical Domains ◽  
Injection Molded

The present study describes the preparation and characterization of binary and ternary blends based on polylactide (PLA) with poly(ε-caprolactone) (PCL) and thermoplastic starch (TPS) to develop fully compostable plastics with improved ductility and toughness. To this end, PLA was first melt-mixed in a co-rotating twin-screw extruder with up to 40 wt % of different PCL and TPS combinations and then shaped into pieces by injection molding. The mechanical, thermal, and thermomechanical properties of the resultant binary and ternary blend pieces were analyzed and related to their composition. Although the biopolymer blends were immiscible, the addition of both PCL and TPS remarkably increased the flexibility and impact strength of PLA while it slightly reduced its mechanical strength. The most balanced mechanical performance was achieved for the ternary blend pieces that combined high PCL contents with low amounts of TPS, suggesting a main phase change from PLA/TPS (comparatively rigid) to PLA/PCL (comparatively flexible). The PLA-based blends presented an “island-and-sea” morphology in which the TPS phase contributed to the fine dispersion of PCL as micro-sized spherical domains that acted as a rubber-like phase with the capacity to improve toughness. In addition, the here-prepared ternary blend pieces presented slightly higher thermal stability and lower thermomechanical stiffness than the neat PLA pieces. Finally, all biopolymer pieces fully disintegrated in a controlled compost soil after 28 days. Therefore, the inherently low ductility and toughness of PLA can be successfully improved by melt blending with PCL and TPS, resulting in compostable plastic materials with a great potential in, for instance, rigid packaging applications.

scholarly journals Characterization of Phosphate Coatings: Influence of the Acid Pickling Conditions

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1048
Author(s):  
Belén Díaz ◽  
X. Ramón Nóvoa ◽  
Carmen Pérez ◽  
Sheila Silva-Fernández
Keyword(s):  
Citric Acid ◽  
High Strength ◽  
Acid Pickling ◽  
Acid Cleaning ◽  
Inorganic Acids ◽  
Phosphate Coatings ◽  
Acid Bath ◽  
Coating Morphology ◽  
Coating Weight

This research emphasizes the importance of the acid cleaning prior to the phosphate development on high-strength steel rods. It compares the phosphate properties achieved after different acid-pickling conditions. The most common inorganic acids were considered in this study. Additionally, taking into account the environmental and safety concerns of these acids, the assessment of a less harmful organic acid is presented. This study revealed significant differences in the coating morphology and chemical composition whereas no great changes were found in terms of the coating weight or porosity. Thus, hydrochloric and sulfuric acid promote the growth of a Fe-enriched phosphate layer with a less conductive character that is not developed after the pickling with phosphoric acid. The phosphate developed after the citric acid pickling is comparable to that developed after the inorganic acids although with a porosity slightly higher. The temperature of the citric acid bath is an important parameter that affects to the phosphate appearance, composition, and porosity.

scholarly journals Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4443
Author(s):  
Jiangyan Huo ◽  
Min Lei ◽  
Feifei Li ◽  
Jinjun Hou ◽  
Zijia Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Gut Microbiota ◽  
Structural Characterization ◽  
Hot Water ◽  
Nmr Analysis ◽  
Gastrodia Elata ◽  
Hot Water Extraction ◽  
Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

Mechanical, Thermal, and Morphological Properties of Thermoplastic Starch/Poly(lactic acid/Poly(butylene adipate-co-terephthalate) Blends

2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Thermoplastic Starch ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Elongation At Break ◽  
Blending Method

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.

Preparation and Characterization of the Nano Powder for Al2O3-SiO2-CaF2 Glass by Homo-Precipitation Method

2007 ◽  
Vol 280-283 ◽  
pp. 1643-1646
Author(s):  
G.C. Yuan ◽  
Q.G. Wu ◽  
G.X. Zeng ◽  
X.H. Zhang
Keyword(s):  
Citric Acid ◽  
Amorphous Structure ◽  
Precipitation Method ◽  
Inorganic Salts ◽  
Mixture Ratio ◽  
Nano Powder ◽  
Desiccation Process ◽  
Amorphous Compounds ◽  
Crystal Phases

The nano-powder of Al2O3-SiO2-CaF2 bio-glass was prepared by the homo-precipitation method with some inorganic salts containing Al3+, Ca2+, Na+, F-, SiO3 2+, Cl- as starting-reagents. The composition and characteristics of the powders were studied with XRD, EDAX, TEM and DTA. The results indicate that the prepared powder belongs to amorphous compounds containing Al, Ca, Si, O and F atoms and the size of particle is in the range of 30 ~ 70 nm. Adding citric acid and the well-controlled desiccation process can slightly improve the dispersing effect of the powders; the mixture ratio of the reagents rarely affects the characteristic of powder. The crystal phase CaF2 was precipitated firstly from the amorphous structure when the temperature is above 600°C, with the temperature rising, Al2SiO5 and Al4.4Si1.2O9.5 etc. crystal phases were precipitated sequentially.

Preparation and characterization of thermoplastic starch composites with fly ash modified by planetary ball milling

2018 ◽  
Vol 191 ◽  
pp. 198-204 ◽  
Author(s):  
Tanjira Sundum ◽  
Katalin Mészáros Szécsényi ◽  
Kaewta Kaewtatip
Keyword(s):  
Fly Ash ◽  
Ball Milling ◽  
Thermoplastic Starch ◽  
Planetary Ball Milling
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