Hot-melt (HM) adhesives offer advantages over their contemporary water-based and solvent-based adhesives like low volatile organic compounds (VOCs), 100% solid, fast drying, setting etc. In recent years, to reduce the...Hot-melt (HM) adhesives offer advantages over their contemporary water-based and solvent-based adhesives like low volatile organic compounds (VOCs), 100% solid, fast drying, setting etc. In recent years, to reduce their dependence on dwindling petroleum resources and due to the enormous use of HM adhesives in packaging areas that demand 100% recyclability, efforts have been devoted to making these formulations completely bio-based, sustainable and biodegradable. In this attempt, research and developments have been focused on using starch, modified starch, soy protein, polylactides, polyamides, lignin and vegetable oils as a partial/fully replacement to the petrochemical</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">based polymers. The huge amount of research going on in the field of bio-based polymers has still not reached its complete potential in the field of HM adhesives. In this review paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> HM adhesives based on sustainable raw materials namely starch, modified starch, polyamides, poly (lactic acid), soy protein and lignin are discussed.展开更多
A selection of 22 low-melting polymers was thermally and rheologically evaluated to be used as hot-melt adhesives in mixed-substrate joining samples. The choice of polymers was based on the published melting point. It...A selection of 22 low-melting polymers was thermally and rheologically evaluated to be used as hot-melt adhesives in mixed-substrate joining samples. The choice of polymers was based on the published melting point. It was required to include a broad variety of different polymers backbones to study the influence of the different polymers comprehensively. A tool-box of widely applicable tests was developed to judge if a thermoplastic polymer is suitable for a hot-melt adhesive application. Melting temperature (onset, peak and offset temperature) and melting enthalpy were determined using standardized methods. Rheological methods were used to characterize the shear rate dependence and the flow behavior at the application temperature. The wetting behavior of the polymers was evaluated with contact angle measurements. The adhesive strength of the most promising candidates was analyzed using the Lumi Frac-adhesion method including the failure pattern.展开更多
Currently, due to scarcity of hydrocarbon resources and the extensive use of water based, solvent based and hot melt adhesives in wood bonding in furniture industries and packaging industries that demand recyclability...Currently, due to scarcity of hydrocarbon resources and the extensive use of water based, solvent based and hot melt adhesives in wood bonding in furniture industries and packaging industries that demand recyclability, compostability and bio-degradability, recently attention has been concentrated to making these formulations completely bio-based, sustainable and biodegradable. Biodegradable hot melt adhesives (HMAs) prepared from natural sources have a potential for use in furniture and packaging industries because of an increase in awareness of environmental issues, the replacement of conventional petroleum-derived hydrocarbon raw materials by renewable, biodegradable and sustainable materials has developed. In terms of environmental issues, such as climate crisis due to an increase of carbon dioxide emission, attempts have been made to produce HMAs using non-hydrocarbon resins, such as polylactic acid (PLA)-based resins, containing no petroleum as a raw material. Polylactic acid was prepared by self-condensation reactions of lactic acid or by lactide ring opening polymerisation, and used for packaging materials, sanitary pads, diapers etc., especially adhesives owing to its excellent processability and the excellent mechanical properties of its HMAs products. Therefore, recently the use of PLA materials as a substitute for non-biodegradable hydrocarbon-based polymers can be considered to be environmentally favourable. Here, we discussed the various uses of PLA as a sustainable and bio-degradable and sustainable hot melt adhesive.展开更多
Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals ...Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly（propylene carbonate）（PPC） is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive（RHMPA） based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics（PC, PMMA, ABS） and metals（aluminium, steel）, which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process（up to 270 °C）. The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.展开更多
The development of adhesive technology is gaining increasing attention in machinery,electronics,aviation,and other fields.However,traditional adhesives are difficult to be peeled and removed after cross-linking and cu...The development of adhesive technology is gaining increasing attention in machinery,electronics,aviation,and other fields.However,traditional adhesives are difficult to be peeled and removed after cross-linking and curing due to the limited solubility in common solvents,which causes pollution and damage to the surface of the adherend.In this work,we synthesized random hyperbranched polyamide-amine hot melt adhesives through Michael addition of 1,8-octanediamine and N,N’-methylene diacrylamide(ODA-RHP HMA).Owing to the presence of various polar groups,ODA-RHP HMA exhibited robust lap shear strength to different substrates,including glass(6.6 MPa),ceramics(10.3 MPa),steel(11.5 MPa),and aluminum(11.8 MPa).Due to the hydrogen bonds in ODA-RHP,the HMA demonstrated intrinsic self-healing ability,which can be used repeatedly when being subjected to cyclic heating and cooling.Since ODA-RHP HMA can be swollen or dissolved in ethanol,the adhesives can be easily removed through erasing.In addition,ODA-RHP exhibited aggregation-induced luminescence due to the tertiary amine structure in the molecular structure of ODA-RHP,which can be used in the field of cultural relics restoration.展开更多
文摘Hot-melt (HM) adhesives offer advantages over their contemporary water-based and solvent-based adhesives like low volatile organic compounds (VOCs), 100% solid, fast drying, setting etc. In recent years, to reduce their dependence on dwindling petroleum resources and due to the enormous use of HM adhesives in packaging areas that demand 100% recyclability, efforts have been devoted to making these formulations completely bio-based, sustainable and biodegradable. In this attempt, research and developments have been focused on using starch, modified starch, soy protein, polylactides, polyamides, lignin and vegetable oils as a partial/fully replacement to the petrochemical</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">based polymers. The huge amount of research going on in the field of bio-based polymers has still not reached its complete potential in the field of HM adhesives. In this review paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> HM adhesives based on sustainable raw materials namely starch, modified starch, polyamides, poly (lactic acid), soy protein and lignin are discussed.
文摘A selection of 22 low-melting polymers was thermally and rheologically evaluated to be used as hot-melt adhesives in mixed-substrate joining samples. The choice of polymers was based on the published melting point. It was required to include a broad variety of different polymers backbones to study the influence of the different polymers comprehensively. A tool-box of widely applicable tests was developed to judge if a thermoplastic polymer is suitable for a hot-melt adhesive application. Melting temperature (onset, peak and offset temperature) and melting enthalpy were determined using standardized methods. Rheological methods were used to characterize the shear rate dependence and the flow behavior at the application temperature. The wetting behavior of the polymers was evaluated with contact angle measurements. The adhesive strength of the most promising candidates was analyzed using the Lumi Frac-adhesion method including the failure pattern.
文摘Currently, due to scarcity of hydrocarbon resources and the extensive use of water based, solvent based and hot melt adhesives in wood bonding in furniture industries and packaging industries that demand recyclability, compostability and bio-degradability, recently attention has been concentrated to making these formulations completely bio-based, sustainable and biodegradable. Biodegradable hot melt adhesives (HMAs) prepared from natural sources have a potential for use in furniture and packaging industries because of an increase in awareness of environmental issues, the replacement of conventional petroleum-derived hydrocarbon raw materials by renewable, biodegradable and sustainable materials has developed. In terms of environmental issues, such as climate crisis due to an increase of carbon dioxide emission, attempts have been made to produce HMAs using non-hydrocarbon resins, such as polylactic acid (PLA)-based resins, containing no petroleum as a raw material. Polylactic acid was prepared by self-condensation reactions of lactic acid or by lactide ring opening polymerisation, and used for packaging materials, sanitary pads, diapers etc., especially adhesives owing to its excellent processability and the excellent mechanical properties of its HMAs products. Therefore, recently the use of PLA materials as a substitute for non-biodegradable hydrocarbon-based polymers can be considered to be environmentally favourable. Here, we discussed the various uses of PLA as a sustainable and bio-degradable and sustainable hot melt adhesive.
基金financially supported by the National Natural Science Foundation of China(Nos.21574019 and 21304015)the Fundamental Research Funds for the Central Universities and the DHU Distinguished Young Professor Program(No.B201303)
文摘Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly（propylene carbonate）（PPC） is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive（RHMPA） based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics（PC, PMMA, ABS） and metals（aluminium, steel）, which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process（up to 270 °C）. The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.
基金supported by the National Natural Science Foundation of China(Nos.51873170 and 11732012)the National Key R&D Program of China(No.2019YFA0706801)+1 种基金the Key Laboratory Construction Program of Xi'an Science and Technology Bureau(No.201805056ZD7CG40)the One Hundred Talents Program of Shaanxi Province and Shaanxi International Science and Technology Cooperation Program Project(No.2020KW-062)。
文摘The development of adhesive technology is gaining increasing attention in machinery,electronics,aviation,and other fields.However,traditional adhesives are difficult to be peeled and removed after cross-linking and curing due to the limited solubility in common solvents,which causes pollution and damage to the surface of the adherend.In this work,we synthesized random hyperbranched polyamide-amine hot melt adhesives through Michael addition of 1,8-octanediamine and N,N’-methylene diacrylamide(ODA-RHP HMA).Owing to the presence of various polar groups,ODA-RHP HMA exhibited robust lap shear strength to different substrates,including glass(6.6 MPa),ceramics(10.3 MPa),steel(11.5 MPa),and aluminum(11.8 MPa).Due to the hydrogen bonds in ODA-RHP,the HMA demonstrated intrinsic self-healing ability,which can be used repeatedly when being subjected to cyclic heating and cooling.Since ODA-RHP HMA can be swollen or dissolved in ethanol,the adhesives can be easily removed through erasing.In addition,ODA-RHP exhibited aggregation-induced luminescence due to the tertiary amine structure in the molecular structure of ODA-RHP,which can be used in the field of cultural relics restoration.
