Hot-Melt Adhesives: Fundamentals, Formulations, and Applications: A Critical Review

2020 ◽  
Vol 8 (1) ◽  
pp. 1-28
Author(s):  
Swaroop Gharde ◽  
Gaurav Sharma ◽  
Balasubramanian Kandasubramanian
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Compounds ◽  
Processing Speed ◽  
Critical Review ◽  
Volatile Organic ◽  
Industrial Use ◽  
Melt Adhesives ◽  
Hot Melt

Hot-Melt Adhesives (HMAs) are typically used in applications where instant sealing is critically required. HMAs are generally preferred for those applications where processing speed is critical. These materials are widely used in various engineering applications, mainly as sealants in leakages and crack filling of walls and roofs. The industrial use of HMAs is most common in glassware and automobiles for gluing glasses in buildings and bonding heavy motor parts. The formulation of HMAs contains a polymer of suitable nature that makes the base for a strong adhesive, and waxes are added to increase the settling time of adhesive. The tackifiers are used to dilute the polymer to adjust the Glass Transition Temperature (Tg) and to reduce the viscosity for proper flow of hot-melt. This review intends to comprehensively discuss the preparation and formulations of HMAs using various polymer matrices, along with their applications and mechanics. The designing of green HMAs has been discussed in the literature and have been promoted over conventional solvent-based HMAs due to their functionality without Volatile Organic Compounds (VOCs). Various measures, challenges, and resolutions for making hazard-free HMAs have been discussed in the present review.

scholarly journals Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

2018 ◽  
Vol 18 (9) ◽  
pp. 6331-6351 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Chemical Composition ◽  
Organic Compounds ◽  
Molar Mass ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Semi Solid ◽  
Oxygen Atoms

Abstract. Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.

scholarly journals Synthesis and Characterization of Polyesteramide Hot Melt Adhesive from Low Purity Dimer Acid, Ethylenediamine, and Ethanolamine

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Pravin G. Kadam ◽  
Parth Vaidya ◽  
Shashank T. Mhaske
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Acid Value ◽  
Peel Strength ◽  
Partial Replacement ◽  
Adhesion Properties ◽  
Dimer Acid ◽  
Lap Shear ◽  
Hot Melt

Polyesteramide hot melt adhesive (HMA) was synthesized using low purity dimer acid (composition: 3% linoleic acid, 75% dimer acid, and 22% trimer acid), ethanolamine, and ethylenediamine. Ethanolamine was added as a partial replacement (10, 20, and 30%) of ethylenediamine. Prepared HMAs were characterized for acid value, amine value, hydroxyl value, Fourier transform infrared spectroscopy, mechanical (tensile strength, percentage strain at brea, and shore D hardness), thermal (glass transition temperature, melting temperature, enthalpy of melting, crystallization temperature, and enthalpy of crystallization), rheological (viscosity versus shear rate and viscosity versus time), and adhesion properties (T-peel strength and lap shear strength). Replacement of ethylenediamine by ethanolamine replaced certain amide linkages by ester linkages, decreasing the intermolecular hydrogen bonding, leading to decrease in the crystallinity of the material, and thus the mechanical, thermal, adhesion, and rheological properties. However, HMAs prepared using ethanolamine will have better low temperature flexibility due to low glass transition temperature and better adhesion process due to the lower viscosity.

Tissue Scaffold Engineering by Micro-Stamping

2014 ◽  
Vol 1626 ◽  
Author(s):  
Eric C. Schmitt ◽  
Robert D. White ◽  
Amrit Sagar ◽  
Thomas P. James
Keyword(s):  
Tissue Engineering ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Room Temperature ◽  
Polymer Membranes ◽  
Tissue Scaffold ◽  
Brittle Behavior ◽  
Excessive Strain ◽  
Hot Melt

ABSTRACTA hand operated benchtop stamping press was developed to conduct research on microscale hole fabrication in polymer membranes for applications as scaffolds in tissue engineering. A biocompatible and biodegradable polymer, poly(ε-caprolactone), was selected for micropunching. Membranes between 30 μm and 50 μm thick were fabricated by hot melt extrusion, but could not be stamped with a 200 μm circular punch at room temperature, regardless of die clearance due to excessive strain to fracture. This problem was overcome by cooling the membrane and die sets with liquid nitrogen to take advantage of induced brittle behavior below the polymer’s glass transition temperature. While cooled, 203 μm hole patterns were successfully punched in 33 μm thick poly(ε-caprolactone) membranes with 11% die clearance, achieving 71% porosity.

scholarly journals Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

2017 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Chemical Composition ◽  
Organic Compounds ◽  
Molar Mass ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Semi Solid ◽  
Oxygen Atoms

Abstract. Secondary organic aerosols (SOA) account for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ~ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg / T) as a function of the fragility parameter D. We compiled D values of organic compounds from literature, and found that D approaches a lower limit of ~ 10 (±1.7) as the molar mass increases. We estimated viscosity of α-pinene and isoprene SOA as a function of RH by accounting for hygroscopic growth of SOA and applying the Gordon-Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, hygroscopicity parameter (κ), and the Gordon-Taylor constant on viscosity predictions. Viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.

scholarly journals Predictions of the glass transition temperature and viscosity of organic aerosols from volatility distributions

2020 ◽  
Vol 20 (13) ◽  
pp. 8103-8122 ◽  
Author(s):  
Ying Li ◽  
Douglas A. Day ◽  
Harald Stark ◽  
Jose L. Jimenez ◽  
Manabu Shiraiwa
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Compounds ◽  
Transport Model ◽  
Organic Aerosols ◽  
Chemical Transport ◽  
Basis Set ◽  
Southeastern Us ◽  
Sulfur Containing

Abstract. Volatility and viscosity are important properties of organic aerosols (OA), affecting aerosol processes such as formation, evolution, and partitioning of OA. Volatility distributions of ambient OA particles have often been measured, while viscosity measurements are scarce. We have previously developed a method to estimate the glass transition temperature (Tg) of an organic compound containing carbon, hydrogen, and oxygen. Based on analysis of over 2400 organic compounds including oxygenated organic compounds, as well as nitrogen- and sulfur-containing organic compounds, we extend this method to include nitrogen- and sulfur-containing compounds based on elemental composition. In addition, parameterizations are developed to predict Tg as a function of volatility and the atomic oxygen-to-carbon ratio based on a negative correlation between Tg and volatility. This prediction method of Tg is applied to ambient observations of volatility distributions at 11 field sites. The predicted Tg values of OA under dry conditions vary mainly from 290 to 339 K and the predicted viscosities are consistent with the results of ambient particle-phase-state measurements in the southeastern US and the Amazonian rain forest. Reducing the uncertainties in measured volatility distributions would improve predictions of viscosity, especially at low relative humidity. We also predict the Tg of OA components identified via positive matrix factorization of aerosol mass spectrometer (AMS) data. The predicted viscosity of oxidized OA is consistent with previously reported viscosity of secondary organic aerosols (SOA) derived from α-pinene, toluene, isoprene epoxydiol (IEPOX), and diesel fuel. Comparison of the predicted viscosity based on the observed volatility distributions with the viscosity simulated by a chemical transport model implies that missing low volatility compounds in a global model can lead to underestimation of OA viscosity at some sites. The relation between volatility and viscosity can be applied in the molecular corridor or volatility basis set approaches to improve OA simulations in chemical transport models by consideration of effects of particle viscosity in OA formation and evolution.

scholarly journals Predictions of the glass transition temperature and viscosity of organic aerosols by volatility distributions

2020 ◽  
Author(s):  
Ying Li ◽  
Douglas A. Day ◽  
Harald Stark ◽  
Jose Jimenez ◽  
Manabu Shiraiwa
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Compounds ◽  
Organic Aerosols ◽  
Chemical Transport ◽  
Basis Set ◽  
Southeastern Us ◽  
Spectrometer Data ◽  
Sulfur Containing

Abstract. Volatility and viscosity are important properties of organic aerosols (OA), affecting aerosol processes such as formation, evolution and partitioning of OA. Volatility distributions of ambient OA particles have often been measured, while viscosity measurements are scarce. We have previously developed a method to estimate glass transition temperature (Tg) of an organic compound containing carbon, hydrogen, and oxygen. Based on analysis of over 2300 organic compounds including oxygenated organic compounds as well as nitrogen- and sulfur-containing organic compounds, we extend this method to include nitrogen- and sulfur-containing compounds based on elemental composition. In addition, parameterizations are developed to predict Tg as a function of volatility and the atomic oxygen-to-carbon ratio based on a negative correlation between Tg and volatility. The prediction method of Tg and viscosity is applied to ambient observations of volatility distributions at eleven field sites. The predicted Tg varies mainly from 290 K to 339 K and the predicted viscosities are consistent with the results of ambient particle phase state measurements in the southeastern US and the Amazonian rain forest. Reducing the uncertainties in measured volatility distributions would be helpful to improve predictions of viscosity especially at low relative humidity. We also predict the Tg of OA components identified via positive matrix factorization of aerosol mass spectrometer data. The predicted viscosity of oxidized OA is consistent with previously reported viscosity of SOA derived from α-pinene, toluene, isoprene epoxydiol (IEPOX), and of diesel fuel. Comparison of the predicted viscosity based on the observed volatility distributions with the viscosity simulated by a chemical transport model implies that missing low volatility compounds in a global model can lead to underestimation of OA viscosity at some sites. The relation between volatility and viscosity can be applied in the molecular corridor or volatility basis set approaches to improve OA simulations in chemical transport models by consideration of effects of particle viscosity in OA formation and evolution.

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