scholarly journals Mechanical and Thermal Characteristics of Bio-Nanocomposites Consisting of Poly-L-lactic Acid and Self-Assembling Siloxane Nanoparticles with Three Phases

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Masatoshi Iji ◽  
Naoki Morishita
Keyword(s):  
Lactic Acid ◽  
Thermal Characteristics ◽  
Decomposition Temperature ◽  
Maximum Strength ◽  
Breaking Strain ◽  
Self Assembling ◽  
Heat Distortion Temperature ◽  
Average Size ◽  
The Impact ◽  
Three Phases

Biopolymer nanocomposites (bio-nanocomposite) consisting of poly-L-lactic acid (PLLA) and siloxane nanoparticles with three phases, a high-density siloxane phase (plural cores), an elastomeric silicone phase, and a caprolactone oligomer phase, were developed to increase the mechanical properties of PLLA. The nanoparticles, average size of 13 nm, were self-assembled by aggregation and condensation of an organosiloxane with three units: isocyanatepropyltrimethoxysilane (IPTS), polymethylpropyloxysiloxane (PMPS), and a caprolactone oligomer (CLO), which form each phase. The bio-nanocomposite was produced using PLLA and the nanoparticles. Bending and tensile testing showed that the use of these nanoparticles (5 wt% in PLLA) greatly increases the tenacity (breaking strain) of PLLA while maintaining its relatively high breaking (maximum) strength. The elongation of the nanocomposite was more than twice that of PLLA while the elasticity modulus and breaking (maximum) strength were comparable to those of PLLA. The nanoparticles also increased the impact strength of PLLA. The use of the nanoparticles almost did not show adverse affect on the thermal resistance of PLLA. The nanocomposite’s heat resistance indicated by the glass transition temperature and heat distortion temperature was fairly kept. The decomposition temperature of the nanocomposite somewhat increased.

scholarly journals Impact of lattice inclusion of Cu and Fe ions on thermal decomposition characteristics of ammonium perchlorate

2020 ◽  
Vol 2 ◽  
pp. e1
Author(s):  
Savitha Nair ◽  
Suresh Mathew ◽  
Reghunadhan C.P. Nair
Keyword(s):  
Thermal Decomposition ◽  
Ammonium Perchlorate ◽  
Thermal Characteristics ◽  
Ionic Species ◽  
Decomposition Temperature ◽  
Solid Rocket Propellant ◽  
Ballistic Properties ◽  
Solid Rocket ◽  
The Impact ◽  
Fe Ions

Ammonium perchlorate (AP) is the universal oxidiser in use for all the solid rocket propellant motors used for space exploration due to its high available oxygen content and thermal decomposition without any solid residue. The inclusion of reactive species in AP directly affect the viscoelastic and ballistic properties of the propellant. Variations in lattice configuration of AP change its physical and thermal characteristics dramatically. In the present work AP was doped with Copper perchlorate and Iron perchlorate through co crystallisation. The impact of inclusion of these ionic species in the lattice on the thermal decomposition characteristics of AP was examined. The incorporation affected the physical as well as the ballistic characteristics of the resultant AP. The incorporation of foreign ions into AP crystals significantly changed the crystal morphology. The decomposition temperature decreased vis-a-vis with normal AP. The activation energy remarkably decreased for the doped AP crystals.

scholarly journals Self-assembling siloxane nanoparticles with three phases that increase tenacity of poly L-lactic acid

2010 ◽  
Vol 43 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Masatoshi Iji ◽  
Naoki Morishita ◽  
Hiroyuki Kai
Keyword(s):  
Lactic Acid ◽  
Self Assembling ◽  
Three Phases

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

scholarly journals Poly(Lactic Acid)–Poly(Butylene Succinate)–Sugar Beet Pulp Composites; Part I: Mechanics of Composites with Fine and Coarse Sugar Beet Pulp Particles

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2531
Author(s):  
Rodion Kopitzky
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Sugar Beet ◽  
Cell Structure ◽  
Sugar Beet Pulp ◽  
Poly Lactic Acid ◽  
Butylene Succinate ◽  
Fracture Patterns ◽  
Beet Pulp ◽  
The Impact

Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds based on bio-based polyesters. The heterogeneous cell structure of sugar beet suggests that the processing of SBP can affect the properties of the composite. An “Ultra-Rotor” type air turbulence mill was used to produce SBP particles of different sizes. These particles were processed in a twin-screw extruder with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) and fillers to granules for possible marketable formulations. Different screw designs, compatibilizers and the use of glycerol as a thermoplasticization agent for SBP were also tested. The spherical, cubic, or ellipsoidal-like shaped particles of SBP are not suitable for usage as a fiber-like reinforcement. In addition, the fineness of ground SBP affects the mechanical properties because (i) a high proportion of polar surfaces leads to poor compatibility, and (ii) due to the inner structure of the particulate matter, the strength of the composite is limited to the cohesive strength of compressed sugar-cell compartments of the SBP. The compatibilization of the polymer–matrix–particle interface can be achieved by using compatibilizers of different types. Scanning electron microscopy (SEM) fracture patterns show that the compatibilization can lead to both well-bonded particles and cohesive fracture patterns in the matrix. Nevertheless, the mechanical properties are limited by the impact and elongation behavior. Therefore, the applications of SBP-based composites must be well considered.

scholarly journals The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wuyang Huang ◽  
Ky Young Cho ◽  
Di Meng ◽  
W. Allan Walker
Keyword(s):  
Lactic Acid ◽  
Mechanistic Model ◽  
Transcriptomic Analysis ◽  
Dependent Manner ◽  
Protective Effects ◽  
Very Preterm Infants ◽  
Anti Inflammatory ◽  
The Impact

AbstractAn excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA’s effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

scholarly journals Insulation Characteristics of Sisal Fibre/Epoxy Composites

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
A. Shalwan ◽  
M. Alajmi ◽  
A. Alajmi
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Thermal Characteristics ◽  
Fibre Volume ◽  
Point Of View ◽  
Natural Fibres ◽  
Epoxy Composites ◽  
Ongoing Research ◽  
Sisal Fibre ◽  
The Impact

Using natural fibres in civil engineering is the aim of many industrial and academics sectors to overcome the impact of synthetic fibres on environments. One of the potential applications of natural fibres composites is to be implemented in insulation components. Thermal behaviour of polymer composites based on natural fibres is recent ongoing research. In this article, thermal characteristics of sisal fibre reinforced epoxy composites are evaluated for treated and untreated fibres considering different volume fractions of 0–30%. The results revealed that the increase in the fibre volume fraction increased the insulation performance of the composites for both treated and untreated fibres. More than 200% insulation rate was achieved at the volume fraction of 20% of treated sisal fibres. Untreated fibres showed about 400% insulation rate; however, it is not recommended to use untreated fibres from mechanical point of view. The results indicated that there is potential of using the developed composites for insulation purposes.

scholarly journals POROSITY PARAMETERS OF CEMENT STONE CONTAINING CHEMICAL ADMIXTURES OF DIFFERENT PURPOSE / CEMENTINIO AKMENS SU SKIRTINGOS PASKIRTIES CHEMINIAIS PRIEDAIS PORINGUMO RODIKLIAI

2013 ◽  
Vol 5 (5) ◽  
pp. 530-535
Author(s):  
Lukas Venčkauskas ◽  
Mindaugas Daukšys
Keyword(s):  
Cement Paste ◽  
Cement Stone ◽  
Hardened Cement ◽  
Closed Porosity ◽  
Hardened Cement Paste ◽  
Chemical Admixtures ◽  
Average Size ◽  
The Impact ◽  
Plasticizing Admixture

The conducted research has established a complex influenceand the impact of separate chemical admixtures of differentpurpose on the parameters of the porosity of hardened cementpaste such as open and closed porosity, the average size of poresand the rates of pore inequality. According to the parametersof the porosity of hardened cement paste, on the basis of A. E.Sheikin’s methodology, the number of freezing-thawing cycleswas predicted. This research used plasticizing, viscosity modifyingand antifoaming admixtures. It has been found that, when theamount of plasticizing admixture in cement paste (W/C–0.45) isconstant and makes 1.1% of the cement mass, and the amountof viscosity modifying and antifoaming the admixture increasesfrom 0.1 to 0.6% and from 0.05 to 0.3% respectively, the openporosity of hardened cement paste varies between 30.21% and31.06%, while closed porosity varies between 5.39% and 6.22%.When the amount of the plasticizing admixture in cement paste(W/C–0.45) exceeds 1.1% of the cement mass, the open porosityof hardened cement paste increases by 1.4 times and closedporosity decreases by 2.5 times. While adding 0.1% of the viscositymodifying admixture to cement paste, the open porosityof hardened cement paste is increased by 1.5 times and closedporosity decreases by 2.4 times. The amount of 0.05% of thecement mass of the antifoaming admixture results in the increasedopen porosity of hardened cement paste by 1.5 times and reducedclosed porosity by 3.5 times. Santrauka Tyrimo metu nustatyta kompleksinė bei atskirų skirtingos paskirties cheminių priedų įtaka cementinio akmens poringumo rodikliams – atvirajam ir uždarajam poringumui, vidutinio porų dydžio ir porų vienodumo rodikliams. Tyrimuose naudoti cheminiai priedai: plastifikuojantis, klampą modifikuojantis ir mišinyje susiformavusias oro poras suardantis priedas. Nustatyta, kad cemento tešloje (V/C – 0,45) esant pastoviam plastifikuojančio priedo kiekiui – 1,0 % cemento masės, klampą modifikuojančio priedo kiekiui kintant nuo 0,1 iki 0,6 %, o mišinyje susiformavusias oro poras suardančio priedo kiekiui kintant nuo 0,05 iki 0,3 %, cementinio akmens atvirasis poringumas svyruoja nuo 30,21 iki 31,06 %, o uždarasis – nuo 5,39 iki 6,22 %. Cemento tešloje viršijus plastifikuojančio priedo 1,1 % cemento masės, cementinio akmens atvirasis poringumas padidėja apie 1,4 karto, o uždarasis poringumas sumažėja apie 2,5 karto. Pridėjus į tešlą 0,1 % cemento masės klampą modifikuojančio priedo, cementinio akmens atvirasis poringumas padidėja apie 1,5 karto, uždarasis poringumas sumažėja apie 2,4 karto. Oro poras suardančio priedo kiekis 0,05 % cemento masės cementinio akmens atvirąjį poringumą padidina apie 1,5 karto, uždarąjį poringumą sumažina apie 3,5 karto.

scholarly journals Australian agricultural scale and corporate agroholdings: environmental and climatic impacts

2017 ◽  
Vol 20 (2) ◽  
pp. 187-190 ◽  
Author(s):  
Bradley Plunkett ◽  
Andrew Duff ◽  
Ross Kingwell ◽  
David Feldman
Keyword(s):  
Large Scale ◽  
Climatic Variability ◽  
Institutional Setting ◽  
Corporate Ownership ◽  
Family Structures ◽  
Climatic Impacts ◽  
The Stability ◽  
Average Size ◽  
The Impact ◽  
Concentrate Production

The average size of Australian farms in scale and revenue are the globe’s largest. This scale is a result, in part, of low average rural population densities; development patterns in broadacre production; low levels of effective public policy transfers; a stable and suitable institutional setting suitable for corporate and other large scale investment; and low yields. It is also a factor of the natural variability of the country’s climatic systems which have contributed to the scale of extensive northern cattle production; this variability has implications for the pattern of ownership of broadacre and extensive production. Corporate ownership, tends to concentrate production aggregations at sufficient scale to offset its additional overheads in areas of relative climatic stability and to replicate these agroholding aggregations spatially to protect the stability of revenue flows. Family structures are more dominant in areas of greater climatic variability. Of interest is the impact that any increasing climatic variability (versus rapid changes in technology) may have upon this pattern.

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