scholarly journals Using Chain Extenders to Modify Release Rates of Orange Oil from Poly(Urea-Urethane) Microcapsules

2015 ◽  
pp. 700-708
Author(s):  
Jurij Pušla
Keyword(s):  
Release Rates ◽  
Orange Oil ◽  
Modify Release ◽  
Chain Extenders

scholarly journals The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 890
Author(s):  
Mateusz Barczewski ◽  
Olga Mysiukiewicz ◽  
Aleksander Hejna ◽  
Radosław Biskup ◽  
Joanna Szulc ◽  
...  
Keyword(s):  
Impact Strength ◽  
Mechanical Stability ◽  
Thermomechanical Analysis ◽  
Thermomechanical Properties ◽  
Phenyl Isocyanate ◽  
Sem Analysis ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Expanded Vermiculite ◽  
Chain Extenders

In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.

scholarly journals Development of FGF-2-loaded electrospun waterborne polyurethane fibrous membranes for bone regeneration

2020 ◽  
Author(s):  
Chi Zhang ◽  
Jianxiong Wang ◽  
Yujie Xie ◽  
Li Wang ◽  
Lishi Yang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Periodontal Regeneration ◽  
Waterborne Polyurethane ◽  
Related Factors ◽  
Positive Meaning ◽  
Chain Extenders ◽  
Biomimetic Membrane ◽  
Fibrous Membranes ◽  
Green Chemical Synthesis ◽  
Gbr Membrane

Abstract Guided bone regeneration (GBR) membrane has been used to improve functional outcomes for periodontal regeneration. However, few studies have focused on the biomimetic membrane mimicking the vascularization of the periodontal membrane. This study aimed to fabricate waterborne polyurethane (WPU) fibrous membranes loaded fibroblast growth factor-2 (FGF-2) via emulsion electrospinning, which can promote regeneration of periodontal tissue via the vascularization of the biomimetic GBR membrane. A biodegradable WPU was synthesized by using lysine and dimethylpropionic acid as chain extenders according to the rule of green chemical synthesis technology. The WPU fibers with FGF-2 was fabricated via emulsion electrospinning. The results confirmed that controlled properties of the fibrous membrane had been achieved with controlled degradation, suitable mechanical properties and sustained release of the factor. The immunohistochemical expression of angiogenic-related factors was positive, meaning that FGF-2 loaded in fibers can significantly promote cell vascularization. The fiber scaffold loaded FGF-2 has the potential to be used as a functional GBR membrane to promote the formation of extraosseous blood vessels during periodontal repairing.

scholarly journals Dissolution Testing of Nicotine Release from OTDN Pouches: Product Characterization and Product-to-Product Comparison

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Fadi Aldeek ◽  
Nicholas McCutcheon ◽  
Cameron Smith ◽  
John H. Miller ◽  
Timothy L. Danielson
Keyword(s):  
In Vitro Release ◽  
Product Category ◽  
Immediate Release ◽  
Tobacco Product ◽  
Oral Dosage ◽  
Dissolution Testing ◽  
Release Rates ◽  
Usp 4 ◽  
Release Profiles

In recent years, oral tobacco-derived nicotine (OTDN) pouches have emerged as a new oral tobacco product category. They are available in a variety of flavors and do not contain cut or ground tobacco leaf. The on!® nicotine pouches fall within this category of OTDN products and are currently marketed in seven (7) flavors with five (5) different nicotine levels. Evaluation of the nicotine release from these products is valuable for product assessment and product-to-product comparisons. In this work, we characterized the in vitro release profiles of nicotine from the 35 varieties of on!® nicotine pouches using a fit-for-purpose dissolution method, employing the U.S. Pharmacopeia flow-through cell dissolution apparatus 4 (USP-4). The nicotine release profiles were compared using the FDA’s Guidance for Industry: Dissolution Testing of Immediate Release Solid Oral Dosage Forms. The cumulative release profiles of nicotine show a dose dependent response for all nicotine levels. The on!® nicotine pouches exhibit equivalent percent nicotine release rates for each flavor variant across all nicotine levels. Furthermore, the nicotine release profiles from on!® nicotine pouches were compared to a variety of other commercially available OTDN pouches and traditional pouched smokeless tobacco products. The percent nicotine release rates were found to be dependent on the product characteristics, showing similarities and differences in the nicotine release profiles between the on!® nicotine pouches and other compared products.

Microcellular foaming of poly(lactic acid) branched with food‐grade chain extenders

2021 ◽  
Vol 138 (29) ◽  
pp. 50686
Author(s):  
Krishnaa B. Venkatesan ◽  
Sonal S. Karkhanis ◽  
Laurent M. Matuana
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Food Grade ◽  
Microcellular Foaming ◽  
Chain Extenders

scholarly journals Potential for the Postharvest Biological Control of Phthorimaea operculella (Lepidoptera, Gelechiidae) by Blattisocius tarsalis (Mesostigmata, Blattisociidae)

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 288
Author(s):  
Jorge Gavara ◽  
Ana Piedra-Buena ◽  
Estrella Hernandez-Suarez ◽  
Manuel Gamez ◽  
Tomas Cabello ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Storage Conditions ◽  
Control Agent ◽  
Phthorimaea Operculella ◽  
Effect Of Temperature ◽  
Potato Storage ◽  
Release Rates ◽  
Blattisocius Tarsalis ◽  
Predatory Capacity ◽  
Pest Density

Phthorimaea operculella is one of the most important pests causing damage to stored potatoes. In this work, the effect of temperature (at 10, 20 and 30 °C) on the predation of pest eggs by Blattisocius tarsalis was studied in the laboratory. In addition, the effect of three predatory release rates on two pest densities was studied under microcosm conditions. The results showed that B. tarsalis maintains its predatory capacity at low temperatures (10 °C), obtaining an efficiency of 49.66 ± 5.06% compared to the control. In turn, at 20 °C, a maximum efficacy of 78.17 ± 4.77% was achieved, very similar to that presented at 30 °C (75.57 ± 4.34%). Under microcosm conditions and at low pest density (10 eggs/container), the mortality due to the mite was 96.97 ± 3.03%, 81.82 ± 8.84%, and 84.85 ± 8.30%, respectively, for the three predatory release rates (5, 10 or 20 mites/container). At the high infestation level, the pest control ranged from 61.54 ± 9.21% to 92.31 ± 2.74%, depending on the predatory release rate. The results obtained show that B. tarsalis could be a relevant control agent against P. operculella under non-refrigerated potato storage conditions, as well as in the first stages of their storage under refrigerated conditions.

Identification of novel α-gliadin genes

Genome ◽  
2011 ◽  
Vol 54 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Peng-Fei Qi ◽  
Yu-Ming Wei ◽  
Qing Chen ◽  
Thérèse Ouellet ◽  
Jia Ai ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Triticum Aestivum L ◽  
Protein Band ◽  
Cysteine Residues ◽  
Disulphide Bonds ◽  
Chain Extenders ◽  
Domain I ◽  
Unique Domain

Ten novel α-gliadin genes (Gli-ta, Gli-turg1, Gli-turg2, Gli-turg3, Gli-turg4, Gli-turg5, Gli-turg6, Gli-cs1, Gli-cs2, and Gli-cs3) with unique characteristics were isolated from wheat ( Triticum aestivum L.), among which Gli-cs1, Gli-cs2, Gli-cs3, and Gli-turg6 were pseudogenes. Gli-cs3 and nine other sequences were much larger and smaller, respectively, than the typical α-gliadins. This variation was caused by insertion or deletion of the unique domain I and a polyglutamine region, possibly the result of illegitimate recombination. Consequently, Gli-cs3 contained 10 cysteine residues, whereas there were 2 cysteine residues only in the other nine sequences. Gli-ta/Gli-ta-like α-gliadin genes are normally expressed during the development of seeds. SDS–PAGE analysis showed that in-vitro-expressed Gli-ta could form intermolecular disulphide bonds and could be chain extenders. A protein band similar in size to Gli-ta has been observed in seed extracts, and mass spectrometry results confirm that the band contains small molecular mass α-gliadins, which is a characteristic of the novel α-gliadins. Mass spectrometry results also indicated that the two cysteine residues of Gli-ta/Gli-ta-like proteins participated in the formation of intermolecular disulphide bonds in vivo.

Species production and heat release rates in two-layered natural gas fires

1991 ◽  
Vol 83 (3-4) ◽  
pp. 325-332 ◽  
Author(s):  
E.E. Zukoski ◽  
J.H. Morehart ◽  
T. Kubota ◽  
S.J. Toner
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Release Rates ◽  
Species Production
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