Melting Peak Temperature Research Articles

Assessment of microstructure and shear strength for low melting point tin-free alloys on Cu

This study explores and compares two new alloys, namely 50In-50Bi and 17Sn-26In-57Bi (wt%), with melting peak temperatures of 95 and 82°C, which are substantially lower than the melting points of lead-free solders commonly used for low-temperature applications. The microstructures and intermetallic compounds (IMCs) of the new alloys, which were reflowed on Cu substrates, were studied. Notable Bi3In5 and BiIn2 compounds were formed in the reflowed 50In-50Bi alloy. The IMCs detected at the interfaces of 50In-50Bi and 17Sn-26In-57Bi were Cu11(In, Bi)9 and Cu6(In, Sn)5, respectively. Shear tests were systematically performed on organic solderability preservative (OSP) Cu substrates with 300-μm openings. Investigation of the fracture surfaces of both alloys indicated that the 17Sn-26In-57Bi/OSP Cu system had the higher shear strength and the more ductile joints.

Poly(Ethylene Glycol Hexadecyl Vinyl Ether) and its Nanofiber with Poly(Acrylonitrile-covinylidene Chloride)

Ethyleneglycol hexadecyl vinyl ether (C16E1VE) as a phase change material was fabricated using ethylene glycol monovinyl ethersodium and bromohexadecane as raw materials through sodium alkoxide method. Poly(ethylene glycol hexadecyl vinyl ether)(PC16E1VE) was synthesized by living cationic polymerization. The molecular weight and its distribution were characterized using gel permeation chromatography. Sheath/core polymeric nanofibers were coaxially electro-spun using it as the core material, and poly(acrylonitrile-co-vinylidene chloride) as a sheath. The composition, phase change properties, thermal stability of C16E1VE, PC16E1VE and the surface morphology of the fibers were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), field emission scanning electronic microscopy(FESEM) and transmission electronic microscopy (TEM), respectively. The results show that, C16E1VE, PC16E1VE and the nanofiber are excellent phase change materials with steady structure, high heat enthalpy and thermal stability. Both the melting and crystallizing enthalpies of PC16E1VE are about 84 J/g. The peak melting temperature and crystallizing temperature are 27.5 and 17.5 oC, respectively. It is thermal stable below 200 oC. These properties indicate that this phase change material can be widely used as a polymeric phase change material in high temperature environments. When the concentration of the P(AN-co-VDC) aqueous solution and PC16E1VE sheath and core spinning solutions were 15 wt%, 60 wt% and spun at flow rates of 1.25 mL/h, 0.375 mL/h, respectively. The fibers show uniform diameters and stable sheath/core structures. Both the melting and crystallizing enthalpies of the nanofibers are about 46 J/g. The peak melting temperature and crystallizing temperature are 34.7 and 23.5 oC, respectively. It is a heat energy storage material with excellent properties.

Effect of Processing Conditions on Heat Seal Strength for Peelable Heat Sealing of Multilayered Polyethylene Films with Different Sealant Layers

ABSTRACTThe effect of heat sealing temperature on peelable heat seal strength (HSS) before and after the sterilization, often used industrially, was investigated for one of either polyethylene (PE) multilayered films with various inner sealant layers consisting of two high density PEs (HDPEs), a linear low density PE (LLDPE) or low density PE (LDPE). To attain similar HSS, heat sealing at a temperature close to the melting peak temperature (Tm-p) was needed only in the case of LDPE. Heat sealing behavior at higher temperatures, to attain higher HSS, was also investigated for HDPE and LDPE. High HSS, as well as suppressed reduction of HSS after the sterilization, was achieved for HDPE at a heat sealing temperature well below its Tm-p. An Increase of HSS with the increase of dwell time was also observed. On the other hand, for LDPE, high HSS and its stability after the sterilization were achieved only when the heat sealing temperature was increased to the value equivalent to its Tm-p. Improvement of the processing conditions for the shortening of the processing period was also investigated. For HDPE, higher sealing bar temperature was needed to gain similar HSS when the dwell time of the heat sealing was shortened from 4 to 2 s, whereas the attained maximum temperature at the interface was found to be similar. The characteristics of the heat sealed portion, judged from the relation between HSSs before and after the sterilization, were not affected by the dwell time of heat sealing, indicating that the shortening of the processing time by appropriate raising of the sealing bar temperature is possible.

Differential Scanning Calorimetry Studies on the Cold Flow Properties of Fuel Mixtures from Bio-Oil, Crude Glycerol, Methanol, and/or Biochar

Differential scanning calorimetry is employed to investigate the cold flow property of a series of fuel mixtures prepared from fast pyrolysis bio-oil, crude glycerol, methanol, and/or biochar. Bio-oil alone has a melting peak temperature (TMP) of −21.9 °C that may lead to difficulties in practical applications under extreme cold weather conditions. Bio-oil water-soluble fraction (WSF) is even more problematic as its TMP is −8.7 °C. The results show that these problems can be alleviated or even eliminated by mixing various formulated crude glycerols (FCGs) with bio-oil or WSF. The TMP of FCG/methanol/bio-oil (FCGMB) blends significantly decreased from −21.9 to −38.1 °C. Similar phenomena were also seen for the FCG/WSF (FCGWSF) blends, with decreases in TMP from −8.7 to −32.0 °C. Water can worsen the cold flow properties of FCGMB and FCGWSF blends. However, other components in FCGs can lower the TMP and hence improve the cold flow properties of these fuel mixtures (with the effectiveness in the order of NaC...

Simultaneous detection and identification of pathogenic Cronobacter species by high‐resolution melting analysis in powdered infant formulas

A combination method of real‐time PCR and high‐resolution melting (HRM) analysis for the rapid detection and specific classification of six pathogenic Cronobacter species based on gene cgcA was developed. HRM profiles with distinct Tm (melting temperature) peaks were consistently obtained with each species, represented by a single peak ranging from 86.02 to 86.80 °C. The detection limit ranged from 0.1 to 1 pg per reaction. Desiccated Cronobacter sakazakii and Cronobacter muytjensii of 2 cfu/25 g were successfully detected after 4‐week storage at room temperature. The newly developed method provided a molecular tool for direct detection and simultaneous identification of pathogenic Cronobacter species in powdered infant formulae.

Simulation-based optimization of PCM melting temperature to improve the energy performance in buildings

Globally, a considerable amount of energy is consumed by the building sector. The building envelope can highly influence the energy consumption in buildings. In this regard, innovative technologies such as thermal energy storage (TES) can help to boost the energy efficiency and to reduce the CO2 emissions in this sector. The use of phase change materials (PCM), due to its high heat capacity, has been the centre of attention of many researchers. A considerable number of papers have been published on the application of PCM as passive system in building envelopes. Researches have shown that choosing the PCM melting temperature in different climate conditions is a key factor to improve the energy performance in buildings. In the present paper, a simulation-based optimization methodology will be presented by coupling EnergyPlus and GenOpt with an innovative enthalpy-temperature (h-T) function to define the optimum PCM peak melting temperature to enhance the cooling, heating, and the annual total heating and cooling energy performance of a residential building in various climate conditions based on Köppen-Geiger classification. Results show that in a cooling dominant climate the best PCM melting temperature to reduce the annual energy consumption is close to the maximum of 26°C (melting range of 24–28°C), whereas in heating dominant climates PCM with lower melting temperature of 20°C (melting range of 18–22°C) yields higher annual energy benefits. Moreover, it was found that the proper selection of PCM melting temperature in each climate zone can lead to notable energy savings for cooling energy consumption, heating energy consumption, and total annual energy consumption.

Crystallization kinetics of tellurium-rich Se–Te–Sn glassy alloys

Differential scanning calorimetry (DSC) has been used to study the non-isothermal crystallization kinetics of Se30Te70−xSnx (for x = 0, 1.5 2.5 and 4.5) glassy alloys. Characteristic kinetic parameters say glass transition temperature (T g), peak crystallization temperature (T p) and melting temperature (T m) are determined from the DSC curves, recorded at four different heating rates, i.e., 9, 12, 15, 18 K min−1. The characteristic temperatures T g, T c and T m are found to increase with an increase in Sn concentration as well as with the heating rate (α). The increase in T g, T p and T m may be ascribed to the increase in cross-linking of amorphous network due to the dispersion of Sn into the Se chains. The activation energy of glass transition (E g), crystallization activation energy (E c) and Avrami exponent (n) have been evaluated from the heating rate dependence of T g, T c and T p using Kissinger, Mahadevan, Augis-Bennett and Moynihan methods. Thermal stability and glass-forming ability of amorphous Se30Te70−xSnx alloy have also been examined. Our results show that Se30Te70−xSnx composition, with thermal stability parameter H R > 0.5, is thermally stable and has characteristics of good glass former. Further, the composition corresponding to x = 1.5 is found to be thermally more stable as compared to the other compositions.

Relationship between melting behavior and morphological changes of semicrystalline polymers

The present study on the case of poly(hexamethylene succinate) is to provide a basis for a better understanding of the subtle relationship between melting behavior and morphological changes of semicrystalline polymers. The melting behavior and morphological changes of poly(hexamethylene succinate) during both isothermal secondary crystallization and annealing processes were investigated by DSC and SAXS. DSC results showed that, with increasing crystallization time or annealing time, the melting endotherm continuously shifted to higher temperature, which suggested that some minor structural or morphological changes must occur. However, almost no changes at all on the crystal thickness were observed from SAXS measurements. The observed evidence confirmed that the increase in the melting temperature is not attributed to crystal thickening but crystal perfection. More exactly, the rearrangement and smoothing of tie molecules at the folding surface result in the reduction of the fold surface free energy, which dominantly contributes to the increase in the melting peak temperature. The origin of the new endothermic peak observed after annealing at elevated temperature was also discussed. TMDSC results indicated that the annealing peak resulted from the enthalpy relaxation and devitrification transition of rigid amorphous fraction formed by the driving force of thermodynamic nonequilibrium, rather than usually regarded as the melting of thin lamellae or imperfect crystals formed by annealing secondary crystallization.

Nutritional Evaluation of Oleogel Made from Micronutrient Rich Edible Oils.

The present study examined the nutritional properties of trans-free edible oleogels made from oil blends of rice bran and flaxseed in animal model. Oleogels were prepared by using mixture of palm stearin (PS) with cetyl laurate (CL) and palm stearin (PS) with cetyl caprylate (CC) as oleogelators. The oleogel samples were prepared with 15 weight % oleogelators (2:1 molar ratio of PS:CC or PS:CL) at 60°C with 1 hr constant stirring in blended oil. The prepared oleogel samples were subjected to DSC and XRD studies in order to evaluate their melting and crystal characteristics. Oleogel formed by using PS and CC showed the desired thermal characteristics. The peak melting temperature of the said sample was almost 44.5°C as determined by the DSC technique. The X-ray diffraction study clearly signified that the crystals were well developed. For nutritional evaluation, Male Wister rats were fed with prepared oleogel samples along with control diet for 4 weeks. Animals were divided into four groups. The control group was fed with normal stock diet containing blend of rice bran oil and flaxseed oil (4:1); one was fed with TFA rich vanaspati (TFA content is about 11.20%); experimental groups were fed with oleogel prepared by using PS:CC and oleogel prepared by using PS:CL respectively. Analysis of the blood lipid profile of the four groups was done. In vivo study established the cholesterol lowering properties of prepared oleogel samples which further enhanced the novelty of oleogel as healthy alternative of trans fat. The positive changes were more pronounced in case of rats fed with oleogel prepared with PS:CC as oleogelators. This study provides an elegant approach of producing trans-free edible quality oleogel with recognized cholesterol lowering property.

Water-Blown Polyurethane Foams Showing a Reversible Shape-Memory Effect.

Water-blown polyurethane (PU) foams are of enormous technological interest as they are widely applied in various fields, i.e., consumer goods, medicine, automotive or aerospace industries. The discovery of the one-way shape-memory effect in PU foams provided a fresh impetus for extensive investigations on porous polymeric actuators over the past decades. High expansion ratios during the shape-recovery are of special interest when big volume changes are required, for example to fill an aneurysm during micro-invasive surgery or save space during transportation. However, the need to program the foams before each operation cycle could be a drawback impeding the entry of shape-memory polymeric (SMP) foams to our daily life. Here, we showed that a reversible shape-memory effect (rSME) is achievable for polyurethane water-blown semicrystalline foams. We selected commercially available crystallizable poly(ε-caprolactone)-diols of different molecular weight for foams synthesis, followed by investigations of morphology, thermal, thermomechanical and shape-memory properties of obtained compositions. Densities of synthesized foams varied from 110 to 180 kg∙m−3, while peak melting temperatures were composition-dependent and changed from 36 to 47 °C, while the melting temperature interval was around 15 K. All semicrystalline foams exhibited excellent one-way SME with shape-fixity ratios slightly above 100% and shape-recovery ratios from the second cycle of 99%. The composition with broad distribution of molecular weights of poly(ε-caprolactone)-diols exhibited an rSME of about 12% upon cyclic heating and cooling from Tlow = 10 °C and Thigh = 47 °C. We anticipate that our experimental study opens a field of systematic investigation of rSMEs in porous polymeric materials on macro and micro scale and extend the application of water-blown polyurethane foams to, e.g., protective covers with zero thermal expansion or even cushions adjustable to a certain body shape.

Peculiarities of crystallization in the multiblock copolymers of norbornene and cyclooctene

Crystallinity of statistical multiblock copolymers of norbornene and cyclooctene with nearly equimolar composition and different degrees of blockiness is studied by differential scanning calorimetry including thermal fractionation by successive self-nucleation and annealing and by X-ray diffraction. The copolymers are synthesized via recently invented reaction of polymer cross-metathesis, as a result of interchain exchange between polynorbornene and polyoctenamer in the presence of Grubbs’ catalyst of the first generation. This catalyst raises the fraction of trans-octenylene units up to more than 80% promoting formation of triclinic crystals. The copolymer degree of crystallinity and melting peak temperature decrease with the cross-metathesis conversion. At the same time the equilibrium melting temperature predicted by the Flory theory of copolymer crystallization is not much affected by the interchange reaction. Compared with the pure polyoctenamer or its equimolar blend with polynorbornene, the norborene-cyclooctene copolymers form considerably smaller crystallites. Thermal fractionation makes it possible to find their size distribution, which correlates with the average length of trans-octenylene blocks. Short annealing the multiblock copolymers above their melting points gives rise to a small but persistent endotherm 5–10 degrees above the annealing temperature, which is absent in polyoctenamer and, therefore, may indicate mixing of segregated norbornene and cyclooctene blocks.

Phase diagrams, eutectic mass ratios and thermal energy storage properties of multiple fatty acid eutectics as novel solid-liquid phase change materials for storage and retrieval of thermal energy

A series of binary and multiple fatty acid eutectics such as ternary eutectics, quaternary eutectics and quinary eutectics were successfully prepared and developed as solid-liquid phase change materials (PCMs) by using five kinds of individual fatty acids such as capric acid (CA), lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA) through melt blending followed by ultrasonication method. The eutectic phase diagrams of binary/multiple fatty acid eutectics were plotted and analyzed on the basis of Schrader equation and MATLAB software, and then their eutectic mass ratios were precisely determined by eutectic phase diagrams and differential scanning calorimetry (DSC) analyses. The deviations between the theoretical calculated eutectic mass ratios and the experimental determined eutectic mass ratios of some fatty acid eutectics could be attributed to the experimental errors of data obtaining from the DSC analyses, impurities of fatty acids and cumulative errors of calculation. The results of DSC indicated that phase change temperatures and enthalpies of the synthesized fatty acid eutectics gradually decreased with the increase of the number of components in the mixtures. The melting peak temperatures of the prepared binary eutectics, ternary eutectics, quaternary eutectics and quinary eutectics were varied from about 22 to 56°C, from about 18 to 49°C, from about 19 to 32°C and about 17°C, respectively. Their minimum and maximum melting enthalpies were about 127.2kJ/kg and 204.7kJ/kg, respectively. The spectra obtained from Fourier transformation infrared spectroscope showed that the binary/multiple fatty acid eutectics exhibited the similar carboxyl group with the single fatty acids and had stable chemical properties. The developed fatty acid eutectic mixtures were suitable for low temperature thermal energy storage applications such as solar water heating systems, building energy storage systems, and thermal regulating textiles.

Impact of amylosucrase modification on the structural and physicochemical properties of native and acid-thinned waxy corn starch.

Recombinant amylosucrase from Neisseria polysaccharea was utilized to modify native and acid-thinned starches. The molecular structures and physicochemical properties of modified starches were investigated. Acid-thinned starch displayed much lower viscosity after gelatinization than did the native starch. However, the enzyme exhibited similar catalytic efficiency for both forms of starch. The modified starches had higher proportions of long (DP>33) and intermediate chains (DP 13-33), and X-ray diffraction showed a B-type crystalline structure for all modified starches. With increasing reaction time, the relative crystallinity and endothermic enthalpy of the modified starches gradually decreased, whereas the melting peak temperatures and resistant starch contents increased. Slight differences were observed in thermal parameters, relative crystallinity, and branch chain length distribution between the modified native and acid-thinned starches. Moreover, the digestibility of the modified starches was not affected by acid hydrolysis pretreatment, but was affected by the percentage of intermediate and long chains.

Defining the performance parameters of a rapid screening tool for myotonic dystrophy type 1 based on triplet-primed PCR and melt curve analysis

ABSTRACTBackground: DMPK CTG-repeat expansions that cause myotonic dystrophy type 1 (DM1) can be detected more rapidly, cost-effectively, and simply by combining triplet-primed PCR (TP-PCR) with melting curve analysis (MCA). We undertook a detailed technical validation study to define the optimal operational parameters for performing bidirectional TP-PCR MCA assays.Methods: We determined the assays’ analytic specificity and sensitivity, assessed the effect of reaction volumes, DNA diluents, and common contaminants on melt peak temperature, determined the assays’ sensitivity in detecting low-level mosaicism for repeat expansion, and evaluated their performance on two real-time PCR platforms.Results: Both assays were highly specific and sensitive, and performed optimally under a broad range of parameters. Bidirectional TP-PCR MCA analysis also reduces the risk of generating false-negative results associated with the rare CCG-interruptions that may be present at either end of expanded alleles.Conclusion: The DMPK TP-PCR MCA is a highly specific, sensitive, and significantly cost-saving screening tool for DM1.

Fabrication of crystalline articles of aromatic polycarbonate by hot powder-compaction

Polycarbonate is well known for forming amorphous, transparent, and exceptionally tough articles by conventional methods such as injection molding and extrusion. It is not possible to extrude polycarbonate from the melt into crystalline, shaped articles. A novel method to fabricate crystalline polycarbonate articles from acetone-crystallized powder was devised. The method was adapted from powder metallurgy and it involved compacting acetone-crystallized polycarbonate powder above the glass transition temperature (Tg) and below the melting peak temperature (Tm). The hot powder-compaction process yielded shaped articles, which retained the crystallinity of the original polycarbonate powder. Although the crystallinity of the powder and the articles was less than 20%, surprisingly the articles were non-sticking above the Tg and so could be released from the mold at the compaction temperature. Furthermore, the crystalline polycarbonate articles had a Vicat softening temperature above 180°C, excellent shape and dimension retention above Tg, increased hardness, as well as resistance to acetone and other solvents. That is, the properties were different from those of conventional amorphous polycarbonate articles. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers

Improvement of Properties of Poly(L-lactic acid) through Solution Blending of Biodegradable Polymers

This study concerns the improvement and enhancement of the properties of poly(l-lactic acid) (PLLA) through simple solution blending of pure PLLA with different kinds of biodegradable polymers. Synthesized PLLA was blended with synthesized poly(d,l-lactic acid) (PDLLA) or poly(ethylene glycol) (PEG) at various composition ratios in a solvent mixture of dichloromethane/ethanol at room temperature to produce dipolymer. The polymer-blend properties were analyzed using FTIR, DSC, UTM data and an enzymatic degradation test was conducted. It was found that PLLA blend films were obtained with limitation of the second polymer content up to 20% (w) through solvent casting. From the DSC data, two different melting temperature peaks showed that stereocomplex formation occurred during polymer precipitation for all PLLA/PDLLA blends, while only one single melting temperature peak appeared in the PLLA/PEG blend. Regarding the mechanical properties, the PLLA/PEG blend showed better performance with an improvement of the mechanical strength by around 11.18% and an improvement of the elongation at break by around 89% compared to pure PLLA. Furthermore, after the 48-hour enzymatic biodegradability test, the PLLA/PEG blends showed improvement of biodegradability with 21.88% of sample weight-loss compared to 2.53% for pure PLLA.

Heterogeneous Distribution of Entanglements in a Nonequilibrium Polymer Melt of UHMWPE: Influence on Crystallization without and with Graphene Oxide

In the past, studies have been performed to follow chain dynamics in an equilibrium polymer melt using low molar mass polymers. Here we show that in linear ultrahigh molecular weight polyethylene entanglements formed during or after polymerization are influencing differently the overall chain topology of the polymer melt. When a disentangled UHMWPE sample is crystallized under isothermal conditions after melting, two endothermic peaks are observed. The high temperature peak is related to the melting of crystals obtained on crystallization from the disentangled domains of the heterogeneous (nonequilibrium) polymer melt, whereas the low melting temperature peak is related to the melting of crystals formed from entangled domains of the melt. On increasing the annealing time in melt, the enthalpy of the lower melting temperature peak increases at the expense of the high melting temperature peak due to the transformation of the disentangled nonequilibrium melt into the entangled equilibrium one. However, indep...

A series of electrospun fatty acid ester/polyacrylonitrile phase change composite nanofibers as novel form-stable phase change materials for storage and retrieval of thermal energy

In this paper, a series of fatty acid esters, including ethyl laurate (EL), butyl stearate (BS), ethyl palmitate (EP), ethyl stearate (ES) and methyl palmitate (MP), were selected as the solid–liquid phase change materials (PCMs), and then embedded inside the porous network structure of polyacrylonitrile (PAN) nanofibers supporting the skeleton by electrospinning technology, respectively. Morphological structures, chemical structures and thermal energy storage properties of electrospun fatty acid ester/PAN composite nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC), respectively. Observations by FE-SEM images showed that the PAN nanofibers acting as the supporting polymer matrices can perfectly maintain the fiber shape and effectively prevent the leakage of the molten fatty acid esters. Maximum loaded weight percentages of the EL, BS, EP, ES and MP in the composite solutions could reach up to about 70, 45, 55, 65 and 60 wt.%, respectively. DSC results indicated that the prepared EL/PAN, BS/PAN, EP/PAN, ES/PAN and MP/PAN composite nanofibers had appropriate melting peak temperatures (about 1.26℃, 21.20℃, 29.37℃, 29.66℃ and 31.93℃, respectively) based upon climatic requirement, and the corresponding melting enthalpies were about 84.11, 55.10, 95.37, 93.35 and 110.4 kJ/kg, respectively. It can be considered that electrospun EL/PAN, BS/PAN, EP/PAN, ES/PAN and MP/PAN composite nanofibers would be promising form-stable PCMs for the applications related to the storage and retrieval of thermal energy, such as solar energy storage, building energy conservation, indoor temperature controlling and smart textiles and fibers.

Self-nucleation and crystallization of polyvinyl alcohol

Polyvinyl alcohol (PVA) is a hydrophilic, biodegradable, semicrystalline polymer with a wide array of commercial uses ranging from textiles and packaging to medicine. Film samples of PVA were investigated to assess crystallization and melting behavior during self-nucleation experiments and thermal degradation, using differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis, respectively. TG results show that degradation occurred at temperatures in excess of 200 °C which is close to the observed peak melting temperature of 223 °C. PVA was heated to various self-nucleation temperatures, T s, within its melting range, and then cooled and reheated. Three distinct crystallization regimes were observed upon cooling, depending upon the self-nucleation temperature (T s) selected. At low values of T s, T s < 227 °C, PVA only partially melts, and upon cooling the residual crystals anneal and become more stable. At intermediate values of T s, 228 °C < T s < 234 °C, PVA was found to crystallize exclusively from self-nucleation. For T s > 235 °C, the PVA melts completely and absence of self-nucleation sites causes crystallization to occur at lower temperatures.

Effects of chemical and enzymatic modifications on starch-linoleic acid complex formation

This study investigated the complexation yield and physicochemical properties of soluble and insoluble starch complexes with linoleic acid when a β-amylase treatment was applied to acetylated and debranched potato starch. The degree of acetylation was generally higher in the soluble complexes than in the insoluble ones. The insoluble complexes from the acetylated starch displayed the V-type pattern, whereas, the soluble complexes displayed a mixture of either the A-/V-type or the B-/V-type pattern. Acetylation decreased onset and peak melting temperatures for the insoluble complexes, whereas no melting endotherm was observed in the soluble complexes. Acetylation substantially increased the amount of complexed linoleic acid in the insoluble complexes, but had little positive effect on the formation of the soluble complexes. The β-amylase treatment significantly increased the complexed linoleic content in both soluble and insoluble complexes for the low acetylated starch, but not for the high acetylated starch.