Differential Scanning Calorimetric Measurements Research Articles

Effect of severely thermal shocked MWCNT enhanced glass fiber reinforced polymer composite: An emphasis on tensile and thermal responses

Fiber reinforced polymeric (FRP) composite materials are exposed to diverse changing environmental temperatures during their in-service period. Current investigation is aimed to investigate the influence of thermal-shock exposure on the mechanical behavior of multiwalled carbon nanotube (MWCNT) enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were exposed to +70°C for 36 hrs followed by further exposure to − 60°C for the similar interval of time. Tensile tests were conducted in order to evaluate the results of thermal-shock on the mechanical behavior of the neat and conditioned samples at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with various MWCNT content. The ultimate tensile strength (UTS) was raised by 15.11 % with increase in the 0.1 % MWCNT content GFRP as related to the thermal-shocked neat GFRP conditioned samples. The possible reason may be attributed to the variation in the coefficients of thermal expansion at the time of conditioning. Also, upto some extent the pre-existing residual stresses allows uniform distribution of stress and hence the reason in enhanced mechanical properties of GFRP and MWCNT filled composites. In order to access the modifications in the glass transition temperature (Tg) due to the addition of MWCNT in GFRP composite and also due to the thermal shock temperature modulated differential scanning calorimeter (TMDSC) measurements are carried out. Scanning electron microscopy(SEM) was carried out to identify different modes of failures and strengthening morphology in the composites.

Effect of $$\gamma $$ γ -irradiation on the thermal properties of UHMWPE/MWCNTs nanocomposites: a comparative study of incorporating unmodified and $$\gamma $$ γ -ray-modified MWCNTs

The efficacy of defective sites in MWCNTs as free radical scavengers was investigated on the basis of thermal analysis of ultra-high molecular weight polyethylene (UHMWPE)/MWCNTs and UHMWPE/\(\gamma \)-MWCNTs nanocomposites. Homogenized composites of polyethylene (PE) with MWCNTs and \(\gamma \)-MWCNTs (0.5% by weight) were prepared by the ball milling process for 2 h at a speed of 200 rpm. Thereafter, micron-sized sheets were prepared (by hot pressing) and subjected to \(\gamma \)-dose ranging from 25 to 150 kGy. To investigate the thermal properties and thermal stability, differential scanning calorimetric (DSC) and thermo-gravimetric analysis (TGA) measurements were performed in an inert atmosphere. The results showed that peak melting temperature (\(T_{\mathrm{m}})\) and lamellae thickness (\(L_{\mathrm{c}})\) remained unaltered for UHMWPE/MWCNTs composites; however, for UHMWPE/\(\gamma \)-MWCNTs composites the values varied from 138 to \(141^{\!\circ }\hbox {C}\). This behaviour was attributed to chain scission close to crystalline lamellae due to radiation-induced free radicals, thus reducing the percentage of inter-phase contents within the polymer matrix and enhancing the percentage crystallinity for composites. Furthermore, TGA revealed the higher thermal stability of composites as compared with pristine ones and significant increase in residues percentage for composites, i.e., from \(\sim \) 3 to 7%. These results confirmed the importance of defective sites within the MWCNTs as free radical quenchers, and stopping the chain scission, particularly close to crystalline lamellae, thus preventing loss of the important interphase region of UHMWPE.

Thermodynamics of interaction of ionic liquids with lipid monolayer.

Understanding the interaction of ionic liquids with cellular membrane becomes utterly important to comprehend the activities of these liquids in living organisms. Lipid monolayer formed at the air-water interface is employed as a model system to follow this interaction by investigating important thermodynamic parameters. The penetration kinetics of the imidazolium-based ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4]) into the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid layer is found to follow the Boltzmann-like equation that reveals the characteristic time constant which is observed to be the function of initial surface pressure. The enthalpy and entropy calculated from temperature-dependent pressure-area isotherms of the monolayer show that the added ionic liquids bring about a disordering effect in the lipid film. The change in Gibbs free energy indicates that an ionic liquid with longer chain has a far greater disordering effect compared to an ionic liquid with shorter chain. The differential scanning calorimetric measurement on a multilamellar vesicle system shows the main phase transition temperature to shift to a lower value, which, again, indicates the disordering effect of the ionic liquid on lipid membrane. All these studies fundamentally point out that, when ionic liquids interact with lipid molecules, the self-assembled structure of a cellular membrane gets perturbed, which may be the mechanism of these molecules having adverse effects on living organisms.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

Insights into the interaction mechanism between tiagabine hydrochloride and two serum albumins.

Tiagabine hydrochloride (TGB) is a widely used anticonvulsive drug for the treatment of epilepsy. To better understand the interactions of TGB with plasma proteins, human serum albumin (HSA) and bovine serum albumin (BSA) were selected as model proteins. TGB slightly increased thermal stability of the proteins as confirmed by VP-capillary differential scanning calorimetric (DSC) measurements. Isothermal titration calorimeter (ITC) results showed that TGB could be combined with HSA and BSA moderately, which was also corroborated by fluorescence analysis. Besides, the thermodynamic parameters (ΔH > 0, ΔS > 0) indicated that hydrophobic forces played a major role in the formulation of TGB–HSA and TGB–BSA complexes. Moreover, the main binding sites of TGB to HSA and BSA were also examined by classical fluorescent probe (dansylsarcosine and dansylamide) experiments, showing that TGB and dansylsarcosine competitively interacted with HSA and BSA at the same binding sites. Additionally, TGB had no obvious effect on the conformation change of HSA and BSA as indicated by spectroscopic analyses. This study provides useful information about the interaction mechanism of TGB and serum albumins, which could help to better utilize TGB in biomedical field.

D-mannitol for medium temperature thermal energy storage

D-mannitol is a sugar alcohol with a melting temperature of approximately 167°C. It has been identified as a phase change material for storing heat at a temperature range of about 150–180°C. The outcome of the published research on its applicability for this purpose is inconsistent and sometimes contradictory. We identified that there is a need for further study on the material to overcome such uncertainty. Thus we conducted a series of thermal measurements to quantify its properties and suitability for a phase change thermal storage. Our differential scanning calorimetric measurements showed that the material has a melting temperature of 167°C and fusion heat of 297kJ/kg. However, our accelerated thermal cycling test revealed that this value decreases logarithmically to 249 and 240kJ/kg after 100 and 200 cycles respectively. The material shows a significant level of sub-cooling in DSC measurement with a solidification temperature of approximately 110–120°C which can render the material unsuitable for thermal storage purposes. However, our secondary measurement with a large quantity of D-mannitol shows that such level of sub-cooling is unlikely to occur in a macro-scale sample. We built and tested a thermal storage system containing 3.8kg of D-mannitol to investigate its performance in larger quantities and evaluate the heat transfer properties of the heat exchanger mechanism in the storage system. We show that the material releases significant heat when it is cooled down to 150°C which means implies the occurrence of solidification at a temperature above 150°C.

Effect of oxygen addition on microstructures and mechanical properties of Ti-7.5Mo alloy

The effect of oxygen addition on microstructures and mechanical properties of Ti-7.5Mo (wt.%) alloy has been investigated. The series of Ti-7.5Mo-xO (x = 0, 0.2, 0.3, 0.4 and 0.5 (wt.%)) alloys were solution-treated at 1173 K for 1 h followed by water quenching. Microstructure characterizations were performed by means of X-ray diffraction, scanning electron microscope, as well as transmission electron microscope. The as-quenched microstructure of each alloy was mainly composed of internally twinned α" martensite. The twinning structures in alloys with oxygen contents of zero and 0.5 wt% were both identified as {111}α"-Type I twinning. The precipitated α plates were observed in alloys with higher oxygen contents (≥0.4 wt%). This is attributed to the α-stabilizing effect by the interstitial oxygen atoms, as confirmed by the differential scanning calorimeter measurements. Based on the results of Vickers micro-hardness tests and tensile tests, the hardness, yield strength, ultimate tensile strength, and Young's modulus increased with increasing the oxygen content, while the total elongation and uniform elongation decreased. This is ascribed to the solid-solution strengthening by the addition of oxygen atoms. The present study revealed that Ti-7.5Mo alloy with oxygen content less than 0.3 wt% exhibits an excellent combination of high yield strength and elongation, as well as low Young's modulus; the alloy has good potential as biomedical materials.

Effect of Crosslinking Agent and Branching Agent on Morphological and Physical Properties of Poly(Butylene succinate) Foams

To enhance a viscosity of poly(butylene succinate) (PBS), a crosslinking agent (i.e. dicumyl peroxide, DCP) or branching agent (i.e. Desmodur®N3300, N3300) was incorporated with various amount ranging from 0 to 4 phr via an internal mixer. The thermal transition, rheological properties (e.g. storage modulus, loss modulus, and complex viscosity) and gel content of the compound were determined via differential scanning calorimeter, rheometer, and gel content measurement, respectively. The results revealed that less degree of crystallinity, higher viscosity and more crosslinked structure were detected as increasing amount of DCP and N3300. Subsequently, a compression moulding technique was used to prepare PBS foam with a chemical blowing agent, i.e. azodicarbonamide (ADC). Scanning Electron Microscopy was acquired to examine cell size, cell size distribution, cell structure, and cell density. Besides, physical properties, e.g. foam density and physical appearance, were investigated. The results indicate that the degree of crystallinity, viscosity, and crosslinked structure affect the morphological and physical properties of PBS foams, i.e. greater viscosity and crosslinked structure causing obstacle for cell growth, and less degree of crystallinity allowing easier cell nucleation and cell growth.

Preparation and Characterization of Efficient Flame-Retardant and Thermostability Two-Component Aqueous Varnish Coatings

A method to prepare efficient flame-retardant two-component waterborne polyurethane coatings by combining polyepichlorohydrin, polypropylene glycol, isocyanate, chain-extender and curing agent was developed. The structures and properties of latexes and films were determined by grain size, viscosity, FTIR, differential scanning calorimeter, mechanical properties, thermogravimetry, flame-retardant and applicant measurements. The results illustrated that the more the hydrated double electric layer of two-component varnish coatings latex particles was, the better the resulting mechanical and chemical stability was. The grain size increased and viscosity decreased as stoichiometric ratio of –OH to –NCO became larger. The lower T gs and higher T gh were attributed to the polar extender which hindered aggregation of soft segment in order to accelerate the more drastic movement of the polymer chain. The nonflammability of char layer was weakened as stoichiometric ratio of –OH to –NCO became larger, thus reducing flame-retardant and thermal stability. The limit oxygen index values of all materials exceeded 30%. The two-component varnish coatings had a pretty good water and solvent resistance.

The enhanced and broadband near-infrared emission in Pr3+/Nd3+ co-doped tellurite glass

This paper reports an enhanced and broadband near-infrared fluorescence emission in the Pr3+/Nd3+ co-doped tellurite glass, which was prepared using melt-quenching technique. Under the excitation of 488 nm laser diode (LD), three near-infrared emission bands at around 0.9, 1.04 and 1.30 μm from 3P1,0 → 1G4, 1G4→3H4 and 1G4→3H5 radiative transitions respectively were observed in the Pr3+ single-doped glass, and the fluorescence intensities increased further with the introduction of Nd3+ ions, which is mainly attributed to the energy transfers from Nd3+ to Pr3+ emissions. Meanwhile, the spectral overlapping of Pr3+:1G4→3H4 and Nd3+:4F3/2 → 4I11/2 radiative transitions resulted in a broadband emission ranging from 1000 to 1100 nm, whose full-width at half-maximum (FWHM) reached about 66 nm. Additionally, the spectroscopic properties of Nd3+ and Pr3+ ions were analyzed using Judd-Ofelt theory and the thermal stability property of prepared glass was characterized by the differential scanning calorimeter (DSC) measurement, and larger than 134 °C for the difference ΔT(=Tx−Tg) was observed, which indicates its feasibility for later fiber drawing. The enhanced fluorescence and broadband emission indicate that Pr3+/Nd3+ co-doped tellurite glass can be applied in the near-infrared band tunable lasers and broadband optical amplifiers.

Electrical and dielectric properties of poly(vinyl alcohol)/starch/graphene nanocomposites

Electrical and dielectric properties of poly(vinyl alcohol) (PVA) films, and PVA/starch blend and its nanocomposites with graphene were investigated. The tested materials were prepared via solution mixing and an evaporative casting technique using glycerol as a plasticizer. Differential scanning calorimetric (DSC) measurement data was used to calculate the percentage of crystallinity and glass transition temperature (). Distribution of starch and graphene in the PVA matrix was determined from field emission scanning electron microscopy (FESEM). Effects of the plasticizer and graphene loading on the DC and AC electrical conductivities of the PVA/starch blend were studied. The impact of graphene loadings on the dielectric permittivity (ϵ′), dielectric loss tangent (tan δ), complex electric modulus (M*), and complex impedance (Z*) as a function of frequency were reported. The DC conductivity of PVA was increased with the addition of glycerol and starch. The permittivity of PVA films and PVA/starch/graphene nanocomposites showed a strong frequency‐dependent behaviour in a low frequency zone. The addition of graphene to the PVA/starch blend reduced the area under the semicircles of the Nyquist plot.

Effect of soda lime flux on evaluation of the critical cooling rate of Pd82Si18 amorphous ribbon

Herein, we propose an experimental method based on the Barandiaran–Colmenero relation for evaluating the critical cooling rate (Rc) of Pd82Si18 amorphous ribbon. In this method, to determine the inherent Rc of glass ribbon, heterogeneous nucleation is suppressed during the differential scanning calorimeter measurement process by adding soda lime flux. The Rc values of Pd82Si18 amorphous ribbon were determined before and after soda lime treatment. The experimental results indicate that the Rc values of the treated and non-treated ribbon are 10.27 and 148.39 K/s, respectively. The Rc value of the treated sample is in good agreement with a previous experimental result. Johnson’s relation gives Rc = 22.86 K/s, which confirms the validity of the present results. The results indicate that soda lime flux greatly suppresses heterogeneous nucleation during the measurement process and the inherent Rc of Pd82Si18 is revised. This method provides a new way for evaluating the critical cooling rate by suppressing heterogeneous nucleation.

Effects of Ce+Gd on the structural features and thermal stability of iron-boron-phosphate glasses

In this paper, effect of Ce + Gd incorporation on the structural features and properties of iron borophosphate (IBP) glasses was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and differential scanning calorimetric (DSC) measurements. The results show that the solubility limit of Ce + Gd in the IBP glass with the composition of 36Fe2O3-10B2O3-54P2O5 is about 8 mol%. The structural networks of the Ce + Gd containing IBP glasses consist predominantly of orthophosphate, Q0, groups and pyrophosphate, Q1, groups, along with [BO4] units and a small amount of metaphosphate, Q2, groups. The Ce + Gd incorporation increases the density and Tg but decreases thermal stability of the IBP glass. However, the thermal stability of the Ce + Gd doped IBP glasses increases with Ce + Gd until the contents of Ce + Gd nearly reach the limit solubility. Moreover, the incorporation of Ce + Gd offers depolymerizing effect on the glass networks, which increases the fraction of Q0 and Q1 groups, and decreases the fraction of Q2 groups. The conclusions provide researchers with useful information to understand the roles of Ce + Gd in iron-boron-phosphate based glasses for high-level nuclear waste immobilization.

Fatty acids/1-dodecanol binary eutectic phase change materials for low temperature solar thermal applications: Design, development and thermal analysis

Abstract Thermal phase diagrams are computed for binary mixtures of different fatty acids with 1-dodecanol to design new eutectic phase change materials with melting temperatures and latent heatof fusion ranging from 15.5 to 19 °C and 183 to 188 kJ kg −1 , respectively. The lauric (LA), myristic (MA) and palmitic (PA) fatty acids with 1-dodecanol eutectic compositions are identified and experimentally validated using differential scanning calorimetric measurements. The measured eutectic compositions are 29:71, 17:83, and 10:90 wt% for LA-DE, MA-DE, and PA-DE binary systems respectively. The melting temperatures and latent heat of fusion for these eutectic compositions are 17, 18.43, 20.08 °C and 175.3, 180.8, 191 kJ kg −1 respectively. The computed and measured composition weight fractions, melting temperature and latent heat of fusion values are in good agreement. The suitable melting temperature and considerably large latent heat of fusion for these designed and developed new eutectic phase change materials make them suitable for latent heat thermal energy storage systems for low temperature solar thermal applications such as building heating/cooling and body cooling clothing applications.

Crystal structures, Hirshfeld surface analysis, thermal behavior and dielectric properties of a new organic–inorganic hybrid [C6H10(NH3)2]Cu2Cl8

A novel organic-inorganic hybrid sample [C6H10(NH3)2]Cu2Cl8 has been prepared under mild hydrothermal conditions and characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, FT-IR,NMR and UV–Vis spectroscopies, differential scanning calorimetric and dielectric measurement. It is crystallized in the monoclinic system with P21/c space group. The cohesion and stabilization of the structure are provided by the hydrogen bond interactions, (NH⋯Cl and CH⋯Cl), between [C6H10(NH3)2]2+ cation and [Cu2Cl8]2- anion. The Hirschfeld surface analysis has been performed to explore the behavior of these weak interactions. The presence of different functional groups and the nature of their vibrations were identified by FT-IR and Solid state NMR. The thermal study revealed that this compound undergoes two structural phase transitions around 353 and 376 K. Electrical measurements of our compounds have been investigated using complex impedance spectroscopy (CIS) in the frequency and temperature range 331–399 K and 200 Hz–5 MHz, respectively. The AC conductivity is explained using the correlated barrier hopping model (CBH) conduction mechanism. The nature of DC conductivity variation suggests Arrhenius type of electrical conductivity. A relationship between crystal structure and ionic conductivity was established and discussed. Finally, the real and imaginary parts of the permittivity constant are analyzed with the Cole–Cole formalism and the optical spectra indicate that the compound has a direct band gap (3.14 eV) due to direct transition. The wide band gap is due to low defect concentration in the grown crystal, which is more useful for the laser/optical applications.

Structural, dielectric and conductivity studies of PbFe0.5Nb0.5O3 - BiFeO3 multiferroic solid solution

Single step solid state reaction method was adopted to synthesize (1-x) PbFe0.5Nb0.5O3 (PFN) - (x) BiFeO3 (BFO) (PFN - BFO) multiferroic solid solution with x = 0.1, 0.2, 0.3 and 0.4. Structural analysis of PFN - BFO solid solution was carried out by X Ray Diffraction (XRD) and confirmed the single phase in all solid solutions with negligible amount of pyrochlore (x = 0.2 and 0.4). The Rietveld refined XRD data was well fitted with monoclinic structure (Cm space group). The TEM analysis showed good crystallinity and the average particle size was found to be 100 nm. Dielectric constant (ε′), loss tangent (tan δ) and AC conductivity (σac) of PFN - BFO solid solution were carried out over a wide range of frequency (100 Hz–1 MHz) and temperature (303 K–600 K). The dielectric constant and loss tangent showed the temperature and frequency dependent nature in all solid solutions. The temperature dependent dielectric constant exhibits broad diffuse ferroelectric to paraelectric phase transition with systematic shift in ferroelectric to paraelectric transition temperature (TC). The TC value gets shifted to 423 K, 473 K, 523 K and 563 K for x = 0.1, 0.2, 0.3 and 0.4 respectively and was well supported by differential scanning calorimetric (DSC) measurements. Frequency dependent AC conductivity of PFN - BFO solid solution obeys Johnscher's power law and the conduction mechanism follows Correlated Barrier Hopping (CBH) model. AC conductivity exhibits negative temperature coefficient resistance (NTCR) kind of behaviour.

Effect of pressure with shear stress on gelatinization of starches with different amylose/amylopectin ratios

Effect of pressure with shear stress on the gelatinization of cornstarch with different amylose/amylopectin ratios (waxy 0/100; maze 23/77; G50 50/50; G80 80/20) was systematically investigated using a high-pressure rheometer. Onset and peak temperature of starch gelatinization as well as the peak viscosity were used to discuss the influence of pressure together with shear stress on the gelatinization of starch granules. The results showed that without shear stress, pressure could resist the gelatinization process due to weak swelling of starch granules and lower quantity of amylose released. However, the shear stress can simply counteract the influence of the pressure since its impact is much high on gelatinization. Under certain pressure and shear stress, both onset and peak temperatures of gelatinization were increased with increasing amylose content, which is in correspondence with the results from differential scanning calorimeter measurement, while the overall viscosity was lower when starches with a higher amylose content was used because part of its granular was not fully dissolved during the measurement. SAXS measurements were used to study the gel structure and stability of starch suspensions. It was found that the scattering intensity of starches in the measured range (0.1–1.0 nm−1) is G80 > waxy, indicating the amount of ordered semi-crystalline structures in amylose is higher. Peak values, q = 0.4 nm−1 and q = 0.2 nm−1, detected for waxy starch under different shear rates, indicates that higher shear stress which plays a dominant role compared with pressure, resulted in more degradation in amylopectin, inhibiting the formation of aggregate structure.

The addition of corn fiber gum improves the long-term stability and retrogradation properties of corn starch

This study was designed to test the hypothesis that the stability and physical properties of starch gels could be improved by adding small amounts of corn fiber gum (CFG). In the differential scanning calorimeter measurement, the enthalpy of retrogradation was 7.30 J/g for starch without CFG and 4.30 J/g for starch composite gel with 1.0% CFG. The addition of 1.0% CFG to starch significantly (p < 0.05) decreased the degree of retrogradation during the long-term storage from 61.6% to 36.5%. The addition of CFG retarded the syneresis of the starch system from 17.97% and 34.93%–6.15% and 26.57% after storage for 7 and 14 days respectively. The crystallization peak of starch containing 0.5–1.0% CFG was quite diminished. When compared with the starch gel alone, the addition of CFG significantly lowered the hardness of the composite starch gel from 60.92 to 45.81 N after 14 days storage. The starch gel without CFG showed the lowest rapidly digestible starch content and the highest resistant starch content in comparison to starch/CFG composite gels after 7 and 14 days storage. Over all, the addition of CFG considerably inhibits the retrogradation of corn starch gels during long-term storage.

Thermal stability and non-isothermal crystallization kinetics of Pd82Si18 amorphous ribbon

Rapidly quenched Pd82Si18 ribbon was prepared by melt spinning. The thermal stability and non-isothermal crystallization kinetics of Pd82Si18 amorphous ribbon were investigated by differential scanning calorimeter measurements. Its structure was investigated by X-ray diffraction and transmission electronic microscopy. The activation energy was calculated by the Kissinger method, and the nucleation and growth during non-isothermal crystallization were investigated by the local activation energy and local Avrami exponent. The average activation energy for Pd82Si18 amorphous ribbon based on the Kissinger method is 330.672 kJ/mol, indicating that it has high thermal stability. The local activation energy of the glass ribbon was determined by the Kissinger–Akahira–Sunose method, and the local Avrami exponent was obtained based on the Johnson–Mehl–Avrami model. The calculated local activation energy increases to a maximum when the crystallization column fraction reaches 0.3, and it then decreases, which shows that crystallization is a multistep process. The local Avrami exponent indicates that the crystallization process of Pd82Si18 amorphous ribbon is controlled by volume nucleation with three-dimensional growth at various nucleation rates.

Plasticization of Biodegradable Poly(Lactic Acid) by Different Triglyceride Molecular Sizes: A Comparative Study with Glycerol

In this paper, poly(lactic acid) (PLA) was toughened and softened by four different molecular size plasticizers namely; glycerol, tributyrin, trilaurin and tristearin. Among four plasticizers studied, tributyrin seems the most appropriate plasticizer for PLA due to its proper molecular size. It increased the tensile elongation at break and impact strength by around ten and three times respectively, with only 10 wt% addition. For PLA with trilaurin and tristearin, they did not show the remarkable toughness improvement. Scanning electron microscope (SEM) observation indicated some phase separations of PLA plasticized with glycerol, trilaurin and tristearin, while tributyrin showed its homogeneity to PLA matrix with higher plastic deformations. Under dynamic load, some shifts of the E′ drop and tanδ peak around 10–40 °C were observed, when glycerol and tributyrin was added. Differential scanning calorimeter (DSC) measurements showed some significant shifts of the transition temperatures, while the degree of crystallinity increased slightly. Heat distortion temperature of the blends fluctuated in a small range of 2–3 °C, which still restricted the use of PLA products above 60 °C.