scholarly journals Characterization of Biobased Polyurethane Foams Employing Lignin Fractionated from Microwave Liquefied Switchgrass

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xingyan Huang ◽  
Cornelis F. De Hoop ◽  
Jiulong Xie ◽  
Chung-Yun Hse ◽  
Jinqiu Qi ◽  
...  
Keyword(s):  
Apparent Density ◽  
Foam Cell ◽  
Lignin Content ◽  
Decomposition Temperature ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Sem Images ◽  
Initial Decomposition Temperature ◽  
Biobased Polyurethane ◽  
Pu Foams

Lignin samples fractionated from microwave liquefied switchgrass were applied in the preparation of semirigid polyurethane (PU) foams without purification. The objective of this study was to elucidate the influence of lignin in the PU matrix on the morphological, chemical, mechanical, and thermal properties of the PU foams. The scanning electron microscopy (SEM) images revealed that lignin with 5 and 10% content in the PU foams did not influence the cell shape and size. The foam cell size became larger by increasing the lignin content to 15%. Fourier transform infrared spectroscopy (FTIR) indicated that chemical interactions occurred between the lignin hydroxyl and isocyanate revealing that lignin was well dispersed in the matrix materials. The apparent density of the foam with 10% lignin increased by 14.2% compared to the control, while the foam with 15% lignin had a decreased apparent density. The effect of lignin content on the mechanical properties was similar to that on apparent density. The lignin containing foams were much more thermally stable than the control foam as evidenced by having higher initial decomposition temperature and maximum decomposition rate temperature from the thermogravimetric analysis (TGA) profiles.

scholarly journals Physical Properties of Soy-Phosphate Polyol-Based Rigid Polyurethane Foams

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongyu Fan ◽  
Ali Tekeei ◽  
Galen J. Suppes ◽  
Fu-Hung Hsieh
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Water Content ◽  
Polyurethane Foams ◽  
Solid Polymer ◽  
Mechanical And Thermal Properties ◽  
Blowing Agent ◽  
Isocyanate Index ◽  
Pu Foams

Water-blown rigid polyurethane (PU) foams were made from 0–50% soy-phosphate polyol (SPP) and 2–4% water as the blowing agent. The mechanical and thermal properties of these SPP-based PU foams (SPP PU foams) were investigated. SPP PU foams with higher water content had greater volume, lower density, and compressive strength. SPP PU foams with 3% water content and 20% SPP had the lowest thermal conductivity. The thermal conductivity of SPP PU foams decreased and then increased with increasing SPP percentage, resulting from the combined effects of thermal properties of the gas and solid polymer phases. Higher isocyanate density led to higher compressive strength. At the same isocyanate index, the compressive strength of some 20% SPP foams was close or similar to the control foams made from VORANOL 490.

Mechanical and Thermal Properties of Polyurethane Foams from Liquefied Sugar Beet Pulp

2016 ◽  
Vol 12 (9) ◽  
pp. 911-919 ◽  
Author(s):  
Zhao-qi Zheng ◽  
Li-jun Wang ◽  
Dong Li ◽  
Zhi-gang Huang ◽  
Benu Adhikari ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Regular Structure ◽  
Polyurethane Foams ◽  
Sugar Beet Pulp ◽  
Mechanical And Thermal Properties ◽  
Severe Damage ◽  
Step Method ◽  
Beet Pulp ◽  
One Step ◽  
Pu Foams

Abstract Polyurethane (PU) foams were prepared from microwave liquefied sugar beet pulp (LSBP) and polymethylene polyphenyl isocyanate (PAPI) by using a one-step method. The [NCO]/[OH] ratio was increased from 0.6 to 1.2, and the effect of this ratio on the mechanical, thermal and microstructural properties of the LSBP–PU foams was studied. The allophanate, isocyanurate and free isocyanate were detected in all the foams. The thermal degradation of these foams in air occurred in two main stages; the first one occurred at 200–350 °C and the second one occurred at 300–400 °C. The Tg of the foams increased when the [NCO]/[OH] ratio increased up to 0.9 above which it decreased. As the [NCO]/[OH] ratio increased, the less regular structure and broken cell shape (observed through SEM) indicated that severe damage in structural stability and mechanical properties of LSBP–PU foams occurred. The cellular structure of the foams could be controlled by controlling the gelling and blowing reactions through the control of NCO]/[OH] ratio.

scholarly journals Preparation and Characterization of Polyhedral Octaphenylsilsesquioxane Modified Castor oil based Polyurethane

2018 ◽  
Vol 20 (1) ◽  
pp. 16-25
Author(s):  
Yue Wen ◽  
Pingping Jiang ◽  
Jie Huang ◽  
Agus Haryono ◽  
Jianneng Deng ◽  
...  
Keyword(s):  
Contact Angle ◽  
Castor Oil ◽  
Surface Hydrophobicity ◽  
Decomposition Temperature ◽  
Nano Particles ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Initial Decomposition Temperature ◽  
Static Contact ◽  
Infrared Spectrometer

Vegetable oil-based polyurethanes were synthesized using castor oil (CO) as feedstock, which were characterized by their environmental friendly and renewable properties. Aiming to compensate for shortcomings of these materials, a series of polyurethane/polyhedral octaphenylsilsesquioxane (OPS) hybrids with different OPS contents were prepared by physical mixing in the solutions. Thereafter?chemical structure?morphology and thermal properties of hybrids were characterized through Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), tensile test techniques and static contact angle. The results show that the hybrid polyurethanes display both enhanced glass transition temperatures (Tg), initial decomposition temperature (Td5) and tensile strength with low OPS contents. While with high contents?these values decline with the severe aggregation of nano-particles as shown in the SEM images. Meanwhile, the hybrid polyurethanes displayed enhanced surface hydrophobicity as the contact angle with water revealed

scholarly journals Reinforcement of Castor Oil-Based Polyurethane with Surface Modification of Attapulgite

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1236 ◽  
Author(s):  
Chengshuang Wang ◽  
Lili Dai ◽  
Zhengrui Yang ◽  
Chengcheng Ge ◽  
Shuiping Li ◽  
...  
Keyword(s):  
Storage Modulus ◽  
Castor Oil ◽  
Decomposition Temperature ◽  
Potential Candidate ◽  
Sem Images ◽  
Initial Decomposition Temperature ◽  
Practical Applications ◽  
Uniform Dispersion ◽  
Silane Modification ◽  
Effective Reinforcement

Polyurethane/attapulgite (PU/ATT) nanocomposites derived from castor oil were prepared by incorporation of 8 wt % ATT, acid-treated ATT, and KH560-treated ATT. The effects of three ATTs (ATT, acid-ATT, and KH560-ATT) on the comprehensive properties of PU/ATT nanocomposites were systematically investigated. The results showed that the incorporation of 8 wt % of three ATTs could produce an obvious reinforcement on the castor oil-based PU and that the silane modification treatment, rather than the acid treatment, has the more effective reinforcement effect. SEM images revealed the uniform dispersion of ATT in the PU matrix. DMA confirmed that the storage modulus and glass transition temperature (Tg) of PU/ATT nanocomposites were significantly increased after blending with different ATTs. For PU/KH560-ATT8 nanocomposites, the thermal stability of the PU was obviously enhanced by the addition of KH560-ATT. In particular, 8 wt % KH560-ATT loaded castor oil-based PU nanocomposites exhibit an obvious improvement in tensile strength (255%), Young’s modulus (200%), Tg (5.1 °C), the storage modulus at 25 °C (104%), and the initial decomposition temperature (7.7 °C). The prepared bio-based PU materials could be a potential candidate to replace petroleum-based PU products in practical applications.

Oxazolidone formation: myth or fact? The case of biobased polyurethane foams from different epoxidized triglycerides

2021 ◽  
Author(s):  
Julien Peyrton ◽  
Luc Avérous
Keyword(s):  
Polyurethane Foams ◽  
Biobased Polyurethane

Study of the oxazolidone formation by reaction between disubstituted epoxide and isocyanate in polyurethane foams and model.

scholarly journals Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 700
Author(s):  
Muhamad Hasfanizam Mat Yazik ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohammad Jawaid ◽  
Abd Rahim Abu Talib ◽  
Norkhairunnisa Mazlan ◽  
...  
Keyword(s):  
Shape Memory ◽  
High Performance ◽  
Loss Modulus ◽  
Decomposition Temperature ◽  
Hybrid Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Tan Δ

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

Bio-based Polyurethane-clay Nanocomposite Foams: Systheses and Properties

2009 ◽  
Vol 1188 ◽  
Author(s):  
Min Liu ◽  
Zoran S. Petrovic ◽  
Yijin Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Cell Content ◽  
Modified Clay ◽  
Rigid Polyurethane Foams ◽  
Nanocomposite Foams ◽  
Organically Modified

AbstractStarting from a bio-based polyol through modification of soybean oil, BIOH™ X-210, two series of bio-based polyurethanes-clay nanocomposite foams have been prepared. The effects of organically-modified clay types and loadings on foam morphology, cell structure, and the mechanical and thermal properties of these bio-based polyurethanes-clay nanocomposite foams have been studied with optical microscopy, compression test, thermal conductivity, DMA and TGA characterization. Density of nanocomposite foams decreases with the increase of clay loadings, while reduced 10% compressive stress and yield stress keep constant up to 2.5% clay loading in polyol. The friability of rigid polyurethane-clay nanocomposite foams is high than that of foam without clay, and the friability for nanofoams from Cloisite® 10A is higher than that from 30B at the same clay loadings. The incorporation of clay nanoplatelets decreases the cell size in nanocomposite foams, meanwhile increases the cell density; which would be helpful in terms of improving thermal insulation properties. All the nanocomposite foams were characterized by increased closed cell content compared with the control foam from X-210 without clay, suggesting the potential to improve thermal insulation of rigid polyurethane foams by utilizing organically modified clay. Incorporation of clay into rigid polyurethane foams results in the increase in glass transition temperature: the Tg increased from 186 to 197 to 204 °C when 30B concentration in X-210 increased from 0 to 0.5 to 2.5%, respectively. Even though the thermal conductivity of nanocomposite foams from 30B is lower than or equal to that of rigid polyurethane control foam from X-210, thermal conductivity of nanocomposite foams from 10A is higher than that of control at all 10A concentrations. The reason for this abnormal phenomenon is not clear at this moment; investigation on this is on progress.

Study on Synthesis and Thermal Property of Polyvinylamine

2010 ◽  
Vol 150-151 ◽  
pp. 1500-1503 ◽  
Author(s):  
Hong Chi Zhao ◽  
Qi Li ◽  
Wen Yu Xu ◽  
Fan Huang
Keyword(s):  
Decomposition Temperature ◽  
Characteristic Peak ◽  
Initial Decomposition Temperature ◽  
Nmr Spectrum ◽  
X Ray ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
Chemical Structures ◽  
Thermogravimetric Analyzer ◽  
Infrared Spectrometer ◽  
Thermal Stability Of

Polyvinylamine (PVAm) and polyvinylamine chloride (PVAm•HCl) were synthesized by Hofmann degradation of polyacrylamide (PAM). The reaction condition is gentle and the operation is safe, simple and economical so that it is a good reaction method. The chemical structures and thermal properties of the polymers were studied by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance spectrometer (NMR), X-ray diffractmeter (XRD) and thermogravimetric analyzer (TGA). Synthesis of PVAm•HCl was confirmed by the intensities of the characteristic peak of -CONH2 decreased and the appearance of a new absorption peak at 1530cm-1 (due to N-H bond of -NH3+ ) in the FTIR spectrum, the appearance of the characteristic absorption peaks of carbon atoms in the 13C NMR spectrum, the appearance of chemical shift assignments of proton in 1H NMR spectrum and the appearance of characteristic dispersing diffraction peak between 22.5° to 25.2° in the XRD spectrum, respectively. PAM had three decomposing stages, but PVAm•HCl had two decomposing stages. TG curve of PAM and PVAm•HCl showed that the initial decomposition temperature were 190oC and 140oC, respectively. The thermal stability of PVAm•HCl was poorer than that of PAM.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Polyimide nanocomposites with functionalized graphene sheets

2017 ◽  
Vol 31 (6) ◽  
pp. 837-861 ◽  
Author(s):  
Jin-Hae Chang
Keyword(s):  
Electrical Conductivity ◽  
Filler Content ◽  
Coefficient Of Thermal Expansion ◽  
Barrier Properties ◽  
Decomposition Temperature ◽  
Graphene Sheets ◽  
Functionalized Graphene ◽  
Hybrid Films ◽  
Initial Decomposition Temperature ◽  
Transmission Electron Microscopy Analysis

Polyimide (PI) nanocomposites containing two different functionalized graphene sheets (FGSs) were synthesized, and their thermal properties, morphology, oxygen permeability, and electrical conductivity were compared. Hexadecylamine–graphene sheets and 4-amino- N-hexadecylbenzamide–graphene sheets were utilized. Hybrid films were obtained from blended solutions of PI and FGSs, with the filler content with respect to the PI varying from 0 wt% to 10 wt%. The differences in the properties of the PI matrix were then analyzed with respect to filler content. Transmission electron microscopy analysis confirmed that the two FGSs were dispersed homogeneously throughout the polymer matrix, although some FGS aggregates were also formed. Furthermore, it was observed that the addition of small amounts of FGS nanofiller was sufficient to improve the coefficient of thermal expansion, the gas barrier properties, and the electrical conductivity of the hybrid films. In contrast, the glass transition temperature and the initial decomposition temperature of the PI hybrid films continued to decrease with increasing FGS content.

Sign in / Sign up

Export Citation Format

Share Document