Preparation and Characterisation of Phase Change Material-Loaded Polyurea Microcapsules Several Hundred Micrometres in Diameter

2009 ◽  
Vol 17 (6) ◽  
pp. 365-369 ◽  
Author(s):  
Takayuki Takei ◽  
Masahiro Yoshida ◽  
Tomonori Nagayoshi ◽  
Yasuo Hatate ◽  
Kouichiro Shiomori ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Weight Ratio ◽  
Phenyl Isocyanate ◽  
Toluene Diisocyanate ◽  
Molar Ratio ◽  
Agitation Rate ◽  
Scanning Calorimetry ◽  
Water Emulsion ◽  
Change Material

In the present study, we attempted to prepare phase-change material (PCM)-loaded polyurea microcapsules several hundred micrometres in diameter via oil-in-water emulsion polymerisation. An oil phase with two types of isocyanate monomers (2,4-toluene diisocyanate (TDI) and phenyl isocyanate (PI)) and tetradecane as PCM was dispersed in an aqueous phase with hexamethylene diamine (HMD). The polyurea shell of microcapsules was formed by reaction of the isocyanate monomers with the amine groups derived from HMD and hydrolysed isocyanate monomers. A suitably adjusted agitation rate made it possible to prepare the required microcapsules. An increased molar ratio of TDI to PI in oil phase resulted in improvement of microcapsule morphology. Increased weight ratio of tetradecane to the two isocyanate monomers (TDI and PI) led to an increase in the PCM content in the microcapsules, which is preferable for practical applications. An examination using differential scanning calorimetry analyser demonstrated that the polyurea shell of the microcapsules scarcely influenced the thermal properties of encapsulated tetradecane.

Synthesis and Thermal Properties of Magnesium Sulfate Heptahydrate/Urea Resin as Thermal Energy Storage Micro-Encapsulated Phase Change Material

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Chenzhen Liu ◽  
Ling Ma ◽  
Zhonghao Rao ◽  
Yimin Li
Keyword(s):  
Particle Size ◽  
Thermal Properties ◽  
Phase Change ◽  
Magnesium Sulfate ◽  
Phase Change Material ◽  
Core Material ◽  
Scanning Calorimetry ◽  
Sulfate Heptahydrate ◽  
Encapsulated Phase Change Material ◽  
Change Material

In this study, micro-encapsulated phase change material (microPCM) was successfully synthesized by emulsion polymerization method, using magnesium sulfate heptahydrate (MSH) as core material and urea resin (UR) as shell material. The surface morphologies and particle size distributions of the microPCM were tested by scanning electron microscopy (SEM) and laser particle size analyzer. The chemical structure of microPCM was analyzed by Fourier-transform infrared spectroscopy (FTIR). The thermal properties were investigated by differential scanning calorimetry (DSC) and thermal conductivity coefficient instrument, respectively.

Developing a thermo-regulative system for nonwoven textiles using microencapsulated organic coconut oil

2020 ◽  
pp. 152808372092149
Author(s):  
Saraç E Gözde ◽  
Öner Erhan ◽  
Kahraman M Vezir
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Coconut Oil ◽  
Nonwoven Fabric ◽  
Scanning Calorimetry ◽  
Microencapsulated Phase Change Material ◽  
Nonwoven Textiles ◽  
Composite Fabrics ◽  
Change Material ◽  
Scanning Electron

Organic coconut oil was investigated as a bio-based phase change material in core, and melamine formaldehyde was used as shell material to fabricate microencapsulated phase change material for thermo-regulation in nonwoven textiles. The microcapsules were synthesized using in situ polymerization method. The produced microcapsules (microencapsulated phase change material) were applied by knife coating in different ratios (1:5 and 1.5:5; MPCM: coating paste by wt.) to 100% polypropylene nonwoven, porous, and hydrophilic layer of a laminated, spunbond, and double-layer fabric. The coated layer was confined within two layers of the fabric to develop a thermo-regulative system on the nonwoven fabric to regulate the body temperature in surgeries. The two layers were composed by applying heat (140°C) and pressure (12 kg/cm2). Organic coconut oil, the fabricated microcapsule, and the composite fabrics were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Scanning electron microscopy results revealed that spherical and uniform microcapsules were obtained with an approximate particle size of 2–6 µm. Differential scanning calorimetry results indicated that microencapsulated phase change material and the composite fabrics possessed significant melting enthalpies of 72.9 and 8.4–11.4 J/g, respectively, at peak melting temperatures between 21.6 and 22.8°C within human comfort temperature range. The utilization of coconut oil as a phase change material and the composite integration of this phase change material to a nonwoven fabric bring forward a novelty for future applications.

The Properties of OMMT-PAN-Binary of Fatty Acids Blends as Phase Change Materials

2011 ◽  
Vol 239-242 ◽  
pp. 1101-1104
Author(s):  
Jing Guo ◽  
Heng Xue Xiang ◽  
Cheng Nv Hu
Keyword(s):  
Fatty Acid ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Heat Insulation ◽  
Cooling Curve ◽  
Polyacrylonitrile Fiber ◽  
Scanning Calorimetry ◽  
Thermal Circulation ◽  
Change Material

Using stearic acid-lauric acid binary of fatty acid as phase change material, waste polyacrylonitrile fiber (PAN) as supporting material, organic montmorillonite (OMMT) as modifier, and N, N-dimethylformamide as solvent, OMMT-PAN-binary fatty acid composite phase change materials(PCM) is prepared by solution blending. Using Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TG) study the structure and properties of PCM, the optimized preparation techniques of PCM obtained by orthogonal tests. SEM results showed that the PCM was homogeneous structure, binary of fatty acid dispersed in the continuous phase PAN; TGA results indicated that the degradation of the phase change material can be divided into three steps; DSC results showed that the crystallization enthalpy of PCM reached 143.27 J/g, the phase change temperature was around 23°C, and the DSC thermal circulation showed good thermal stability of the PCM; cooling curve showed that the PCM had good heat insulation properties, holding time reached 800s, and after repeated thermal circulation, heat insulation properties remained the same.

Microencapsulation of n-hexadecane as phase change material by suspension polymerization

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Ai Yafei ◽  
Jin Yong ◽  
Sun Jing ◽  
Wei Deqing
Keyword(s):  
Melting Point ◽  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Suspension Polymerization ◽  
Average Diameter ◽  
Heat Of Fusion ◽  
Synthetic Surfactant ◽  
Scanning Calorimetry ◽  
Change Material

AbstractIn this study, suspension polymerization is described to fabricate microcapsules containing n-hexadecane as phase change material. In the suspension polymerization, casein is employed as emulsifier and stabilizer instead of synthetic surfactant. Microcapsules with polystyrene as shell and n-hexadecane as core have an average diameter of 3~15μm and the size distribution are narrow. Thermal properties are investigated by differential scanning calorimetry (DSC) showing that the microcapsules can store and release an amount of latent heat over a temperature range nearing the melting point of pure n-hexadecane. The latent heat of fusion of microencapsulated n-hexadecane decreases after microencapsulation. The melting point of microencapsulated n-hexadecane is near but higher than that of pure n-hexadecane, and the polymerization time has little effect on the melting point.

Myristic Acid/Montmorillonite Composite as Shape Stabilized Phase Change Material for Thermal Energy Storage

2011 ◽  
Vol 332-334 ◽  
pp. 935-938
Author(s):  
Zhong Li ◽  
Shao Ming Yu ◽  
De Xin Tan ◽  
Tong He Yao
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Myristic Acid ◽  
Xrd Analysis ◽  
High Heat ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis Technique ◽  
New Type ◽  
Change Material

A new type of shape stabilized phase change material (PCM) with good heat storage was produced by intercalating myristic acid (MA) with modifid montmorillonite (MMT). The structure, thermal properties of the composite PCM were determined by X-ray diffraction (XRD), Fourier transformation infrared (FTIR) and Differential Scanning Calorimetry (DSC) analysis technique. In the XRD analysis, expansions of the d spacings in the (001) plane were observed in all samples, indicating that the intercalation of MA in the interlayers of MMT was successfully achieved. The results of DSC indicated that the shape stabilized PCM displayed a high heat capacity (133.6 J.g-1)

Synthesis and properties of a spinnable phase change material CDA-IPDI-MPEG

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Shiliang Cheng ◽  
Yanmo Chen ◽  
Hao Yu ◽  
Meifang Zhu
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Catalyst System ◽  
Molecular Structures ◽  
Size Exclusion ◽  
Dibutyltin Dilaurate ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Exclusion Chromatography ◽  
Change Material

AbstractA comb like phase change material (PCM) CDA-IPDI-MPEG, based on cellulose diacetate (CDA) as a backbone, with methoxy polyethylene glycol (MPEG) grafted onto it, was synthesized by a two-step reaction in the presence of dibutyltin dilaurate (DBTDL) catalyst system, using acetone as solvent and isophorone diisocyanate (IPDI) as crosslinking reagent. Size exclusion chromatography (SEC) was used to characterize the molecular weight distribution of each step reaction products. Back titration was utilized for determination of free isocyanate. The molecular structures were confirmed qualitatively using FTIR and H1-NMR measurements. Phase change properties were characterized by differential scanning calorimetry (DSC).

Study on the Preparation and Properties of PEG Phase Change Materials Fixed by Semi-IPN

2011 ◽  
Vol 299-300 ◽  
pp. 654-658
Author(s):  
Hong Zhang ◽  
Xiao Lei Wang ◽  
Qian Qian Wang
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Three Dimensional ◽  
Molar Ratio ◽  
Good Thermal Stability ◽  
Dimensional Network ◽  
Mass Fractions ◽  
Optimum Formula ◽  
Change Material

Semi-IPN phase change material (PCM) which is suitable for the temperature adjustment textile field is prepared by solution copolymerization. The structure of framework material is a three-dimensional network prepared by N-hydroxymethyl acrylamide, and the phase change material is prepared by polyethylene glycol with molecular weigh 2000. The orthogonal experimental method is used for determining the optimum formula and investigating the various factors on the phase change material properties. Structure and properties of the composite properties are synthesized by SEM, DSC, TGA. The result shows: the advanced process of making composite phase change material is that PEG owns 70% of the overall mass fractions, initiator owns 2.5% of monomer mass fractions, the molar ratio of cross-linker monomer is 1:8, the reaction time is 3 hours, and mass ratio of monomer to water is 1:6. The prepared composite material is distributed uniformly of framework holes, and it has a well fixed effect to the phase change material, which the phase transition temperature is 32.92 °C, the enthalpy is up to 108.41 J / g. It also has a good thermal stability, and applies to the spinning environment which the temperature is not higher than 300 °C.

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