曼尼希改性二乙烯三胺环氧建筑胶固化剂的制备

选用苯酚（P）、甲醛（F）对二乙烯三胺（DETA）进行曼尼希反应改性,研究了产物黏度、胺值与原料配比的关系。将改性的固化剂与环氧树脂E51进行配胶浇注,研究了胶体的力学性能与潮湿环境下的粘接性能。结果表明,P、DETA与F物质的量比[n（P）：n（DETA）：n（F）]=1．5：1．5：1．5的产物综合性能最佳。该固化剂黏度适宜（6542mPa·s）,与E51配胶浇注后,拉伸强度为40MPa,压缩强度达80MPa,潮湿环境下的钢一钢剪切强度为9．2MPa,与混凝土的粘接拉伸强度达47MPa,为混凝土内聚破坏。     

Influence of crosslinking and peeling rate on tack properties of polyacrylic pressure-sensitive adhesives

Tack properties and peeling behavior of crosslinked polyacrylic pressure-sensitive adhesives were investigated. The model adhesive was a crosslinked poly(n-butyl acrylate-acrylic acid) random copolymer with an acrylic acid content of 5?mol% with various crosslinking degrees. Tack was measured using a probe tack test with probe rates of 1 and 10?mm/s and various contact time. The tack increased with contact time. The degree of tack rising with contact time decreased with an increase in crosslinking degree for 10?mm/s, while the tendency was opposite for 1?mm/s. The temperature dependency of tack was measured with a contact time of 30?s. The tack peak shifted to higher temperatures with an increase in crosslinking degree and probe rate. Peeling behavior was observed using high-speed microscopy. The peeling behavior changed from A to C with the decrease of peeling rate and crosslinking degree. A: Cavitation and peeling progressed simultaneously at maximum stress at 10?mm/s independent on the crosslinking degree. B: Cavitation occurred at the edge of the probe at low stress and spread to the center of the probe at maximum stress at 1?mm/s and high crosslinking degree, then peeled out. C: After B, fibrillation occurred at 1?mm/s with low crosslinking degree. The change of peeling behavior was caused by the following: the interfacial adhesion increased, while the cohesive strength decreased as crosslinking degree and probe rate decreased.     

Effect of different acids during the synthesis of urea-formaldehyde adhesives and the mechanical properties of medium-density fiberboards bonded with them

The characteristics of urea-formaldehyde (UF) adhesives condensed by catalysis with four different acids, namely formic (HCOOH), hydrochloric (HCl), phosphoric (H₃PO₄), and sulfuric (H₂SO₄) acids, under alkaline–acidic–alkaline conditions at a molar ratio F/U = 1.12 were studied. The thermal curing properties of UF adhesives catalyzed with acid were characterized by differential scanning calorimetry at 10 °C/min heating rate. The resin structure examined by ¹³C-NMR spectroscopy showed that the resin catalyzed with HCl had a lower proportion of methylol groups, resulting in a lower level of formaldehyde emission. It was interesting to note that HCOOH resulted in the best overall mechanical properties of the medium-density fiberboard (MDF) panels. The HCl catalyst resulted in the poorest performance, providing the lowest internal bond strength, modulus of elasticity, and thickness swelling, with the exception of the free formaldehyde content. The resin catalyzed with H₂SO₄ had the highest free formaldehyde and the highest formaldehyde emission. H₂SO₄ and H₃PO₄ resulted in MDF mechanical properties relatively lower than for HCOOH. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47256.     

LBA钢木结构防盗门胶粘剂

介绍了钢木结构防盗门用LBA胶粘剂所用材料及配制工艺,讨论和评价了有关性能,进行简单的经济分析。     

Effects of apitong (Dipterocarpus spp.) extractives on bond strength development and curing rate of adhesives

Emulsion polymer isocyanate ( ), polyvinyl acetate ( ) and resorcinol-formaldehyde ( ) adhesives were used to produce single lap shear specimens using resinous and non-resinous apitong (Dipterocarpus spp.) timbers. Tests showed that joints made with highly resinous apitong were about 40% weaker than similar joints made with non-resinous apitong. The resinous apitong was treated with different solvents to yield five different extractives which were characterized by infra-red analysis. Apitong extractives were then added to and adhesives and joints made with buna (Fagus crenata), a timber known to be low in extractives and easy to bond. Joints prepared using extractive-containing adhesives were generally weaker than those made with the unmodified adhesives. RF adhesives containing extractives cured more slowly than unmodified . It is thought that the acidic nature of the extractives changes the pH of the system sufficiently to affect the curing mechanism     

新型有机硅多元胺环氧树脂固化剂结构与性能

评价了3种有机硅多元胺APS、SFA和PSPA分别固化环氧树脂E51(DGEBA)时,固化物的力学性能和粘接强度,并与常见脂肪胺类固化剂[乙二胺、己二胺、聚醚胺(D-230)]作了对比。固化物基体力学和热性能测试表明,有机硅多元胺环氧固化物表现出较佳的冲击强度、弯曲强度和热稳定性。有机硅多元胺/环氧树脂胶粘剂的铁片粘接强度以及耐水性明显高于脂肪胺/环氧胶粘剂体系,其中含苯基有机硅多元胺作为固化剂时粘接强度最高,达到14.8 MPa。()     

Synthesis and properties of nylon 6/66/510 used as hot melt adhesives for metal plate with low-surface-energy coating

In this work, nylon 6/66 and nylon 6/66/510 containing 5?～?20?mol % nylon-510 were synthesized to be used as hot melt adhesive for metal plate with low-surface-energy coating. The effects of mole fraction of nylon-510 (X_m) on the thermal and mechanical properties of nylon 6/66/510 were systematically studied. The results demonstrated that: (1) the melting point of the copolyamide decreases and the glass transition temperature decreases when the X_m value increases; (2) the tensile strength of nylon 6/66/510 remains almost unchanged and is almost equal to that of nylon 6/66; (3) the elongation at break of nylon 6/66/510 is significantly higher than that of nylon 6/66. The crystal structure of the copolyamide was also investigated by wide-angle X-ray diffraction (WAXD). The hot-melt adhesives (HMAs) were prepared from nylon 6/66/510, and the adhesive experiments of HMAs to aluminum sheet with low-surface-energy coating were carried out. The results showed that the peeling strength of HMAs based on nylon 6/66/510 reaches a maximum value when X_m = 15?mol %.     

An experimental study on the dependence of the strength of adhesively bonded joints with thickness and mechanical properties of the adhesives

Adhesive bonding joints are widely applied in many engineering fields. Their overall strength is much dependent on the thickness of adhesive layers. Many previous experimental studies have found that the ultimate failure strength of the bonding structure increases with the decrease of the adhesive thickness. However, few of them consider the effect of adhesive intrinsic material parameters on the relation between the overall strength and adhesive thickness. In the present investigation, the effect of the adhesive thickness on the overall strength of the lightweight metallic adhesive bonding joints was experimentally studied, considering the effect of the adhesive toughness. The results show that the variations of overall strength resulting from the adhesive thicknesses have remarkable discrepancy due to the toughness of the adhesive, which is in agreement with the previous model prediction.     

环保型水性聚氨酯复膜胶的开发及其在软包装中的应用

合成出不同结构的水性聚氨酯(WPU)复膜胶,以PET镀铝膜(VMPET)、双向拉伸聚丙烯(BOPP)和聚乙烯(PE)为复合薄膜,探讨了聚酯结构对WPU复膜胶粘接性能的影响,分析了异氰酸酯、水性固化剂和外加溶剂等对WPU复膜胶剥离强度和干燥速率的影响。结果表明:以混合聚酯、芳香族异氰酸酯为主要原料,配合水性固化剂,合成的WPU复膜胶对多种复合薄膜具有较好的粘接性能,其平均剥离强度达到3.48N/15mm;添加少量易挥发的无害溶剂,能够提高水性复膜胶的干燥速率,其最大复合速率达到110m/min,并且完全满足工业化的生产要求。     

Effect of the Crosslinking Agent Content on the Emulsion Polymerization Process and Adhesive Properties of Poly(N-Butyl Acrylate-Co-Methacrylic Acid)

A series of poly(n-butyl acrylate-co-methacrylic acid) with different contents of acrylic crosslinking agent (1,4-butanediol dimethacrylate, BDDA) latexes, named as poly(BA-co-MAA-co-BDDA), PBMABD, were synthesized via a two-stage sequential emulsion polymerization. During the polymerization, the particle sizes of the PBMABD latexes and conversions including instantaneous conversion and overall conversion of monomers were monitored online by dynamic light scattering (DLS) technology and gravimetric analysis in half-hour intervals, respectively. The overall conversions at the end of emulsion polymerization with different crosslinking agent contents were high, and the latex particles grew in a spherical shape without secondary particles during the growth process. The adhesive properties, including loop tack force, peel force and shear resistance, were evaluated systematically according to Fédération Internationale des Fabricants et Transformateurs d'Adhésifs et Thermocollants sur Papiers et Autres Supports (FINAT) test methods. When the content of the crosslinking agent was 0.5?wt%, a best equilibrium among the adhesive properties could be achieved. The adhesive properties of the PBMABD polymer were closely related to its viscoelastic behaviour and molecular structure, such as gel content and various molecular weight parameters.     

Amine-terminated nylon 6/66/1010 (AM-6/66/1010) used for hot melt adhesives: synthesis and properties

A new amine-terminated nylon 6/66/1010 (AM-6/66/1010) copolyamide hot melt adhesive with the molecular weight of 21,000–96,000 Da was synthesized and blocked with 1-hexadecylamine. The AM-6/66/1010 samples were characterized by ¹H-NMR spectroscopy, differential scanning calorimetry (DSC), thermal gravimetric analysis, and gel permeation chromatography. The ¹H-NMR spectroscopy demonstrated that 1-hexadecylamine functions as blocking agent in this polymerization. The DSC thermograms showed that the extra peak (peak (II)) and the melting peak (peak (I)) of AM-6/66/1010 are moving left and the glass transition temperature of AM-6/66/1010 decreases as the mole ratio α_H/C (1-hexadecylamine/total carboxyl) increases. The thermal gravimetric analysis indicated that AM-6/66/1010 hot melt adhesive has a high thermal stability. The peel strength of the test specimen obtained by hot melt glutinous lining of AM-6/66/1010 or AC-6/66/1010 and fabric 6535 (65% PET, 35% cotton) was studied using T-peel tests, and the results showed that the washable and dry-cleaning resistant of AM-6/66/1010 copolyamide hot melt adhesive is better than that of carboxyl-terminated nylon 6/66/1010 (AC-6/66/1010) copolyamide hot melt adhesive.     

粘接制动蹄用耐高温胶粘剂及其粘接性

介绍一种新型酚醛－－丁腈并用耐高温高强度单组分浆状结构胶粘剂和组成比例以及固化条件对粘接强度的影响，该胶适用于粘接刹车制动蹄和飞机轻金属结构等。     

Adhesion properties of pressure-sensitive adhesives prepared from SMR 10/ENR 25, SMR 10/ENR 50, and ENR 25/ENR 50 blends

The adhesion properties, i.e. viscosity, tack, and peel strength of pressure-sensitive adhesives prepared from natural rubber/epoxidized natural rubber blends were investigated using coumarone-indene resin and toluene as the tackifier and solvent respectively. One grade of natural rubber (SMR 10) and two grades of epoxidized natural rubbers (ENR 25 and ENR 50) were used to prepare the rubber blends with blend ratio ranging from 0 to 100%. Coumarone-indene resin content was fixed at 40 parts per hundred parts of rubber (phr) in the adhesive formulation. The viscosity of adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength was determined using a Lloyd Adhesion Tester operating at 30 cm/min. Results show that the viscosity of the adhesive passes through a minimum value at 20% blend ratio. For loop tack and peel strength, it indicates a maximum at 60% blend ratio for SMR 10/ENR 25 and SMR 10/ENR 50 systems. However, for ENR 25/ENR 50 blend, maximum value is observed at 80% blend ratio. SMR 10/ENR 25 blend consistently exhibits the best adhesion property in this study, an observation which is attributed to the optimum compatibility between rubbers and wettability of adhesive on the substrate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Miscibility and adhesive properties of ethylene vinyl acetate copolymer (EVA)‐based hot‐melt adhesives. I. Adhesive tensile strength

A series of ethylene vinyl acetate copolymers (EVA) were blended with some tackifier resins that are made from wood extracts, and possible relations between their miscibility and properties as hot‐melt adhesives (HMA) were investigated. From our previous report on miscibility of various EVA‐based HMAs, we chose some blends that represent some of typical miscibility types and measured their adhesive tensile strengths. When the blends were miscible at testing temperatures, the temperature at which the maximum value of adhesive tensile strength was recorded tended to move toward higher temperature as tackifier content of blends increased. This result corresponds to the glass transition temperature (T_g) of the blends that became higher as tackifier content of blends increased when blend components were miscible. In terms of HMA performances, we suggest that factors other than miscibility affect absolute values of adhesive tensile strength more directly than miscibility; this idea has to be investigated further in a future study. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 719–725, 2002     

Preparation and properties of environment-friendly acrylic latex laminating adhesives applied in plastic/plastic composite films

Acrylic latex laminating adhesives (ALLAs) were successfully prepared via a monomer-starved seeded semi-continuous emulsion polymerization with butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), acrylamide (Am), and methacrylate glycidyl ether (GMA) as monomers. Impacts of GMA on the final latex, the dried latex films and the adhesive properties of ALLAs were investigated, respectively. The results indicated that the increase of GMA contents in the pre-emulsion feed has no apparent effect on the final latex average particle size and size distribution, while the gel contents, glass transition temperature (T_g) and water contact angle of the ALLAs gradually increased, and the molecular weight (M_n, M_w) obviously increased. Additionally, as the amount of GMA increased from 0 to 10?wt%, the maximum peel strength of the composite films reached 3.72 N/15mm with 5?wt% GMA contents. When heated to 65?°C, the peel strength of the composite films with 5?wt% of GMA can still maintain an acceptable peel strength (2.51 N/15mm) for application, showing excellent adhesive performance and heat resistance properties.     

Effect of particle structure on the peel strength and heat resistance properties of vinyl acetate/acrylate latexes laminating adhesives

The concept of using particle structure design to prepare emulsion laminating adhesives (LAs) for improving both the peel strength and heat resistance properties has been investigated. The homogeneous particle latices based on vinyl acetate/acrylate copolymer (samples 1–3) were synthesized by seeded semicontinuous emulsion polymerization with different chain transfer agent (CTA) contents but with no functional monomers, while the core‐shell structure crosslinkable latices (samples 4 and 5) were prepared through multistage polymerization technique. The emulsion particle structure was investigated by TEM and particle size analyzer. The results indicate that the average emulsion particle diameter is about 130 nm and the particles grow without secondary nucleation. Samples 1 and 2 prepared with 0.7 and 0.5 phm (per hundred gram monomer) CTA respectively, show high peel strength but poor heat resistance property. On the contrary, the sample 3 prepared with 0.1‐phm CTA exhibits low peel strength but relatively good heat resistance. However, sample 4, which was synthesized with 0.5‐phm CTA and 0.4‐phm acetoacetoxy ethyl methacrylate (AAEM) in core but 0.5‐phm CTA and 0.6‐phm AAEM in shell stages, shows high peel strength (1032.9 g/in.) and good heat resistance property (524.9 g/in.). In addition, sample 5 also demonstrates high peel strength (987.2 g/in.) and good heat resistance property (643.5 g/in.) when it was synthesized using 0.1‐phm CTA but no AAEM in core, 0.36‐phm CTA and 0.75‐phm AAEM in shell stages. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Novel pyridinium photoinitiators and their applications for the ultraviolet crosslinking of acrylic pressure‐sensitive adhesives

The demand for ultraviolet (UV)‐crosslinkable pressure‐sensitive adhesives (PSAs) has rapidly been increasing. A variety of different PSAs containing new photoreactive pyridinium derivatives have been evaluated for their effectiveness in improving adhesion and cohesion in UV‐crosslinkable PSAs. PSAs have been evaluated with respect to the tack, peel adhesion, and shear strength. This article summarizes the breakthrough technology used to achieve better performances in UV‐crosslinkable acrylic PSAs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Bonding effectiveness of different dentin conditions on etch-and-rinse mode of two universal adhesives: the confocal laser scanning and shear bond strength

The purpose of this study was to evaluate the shear bond strength and the morphological differences of adhesive/dentin interface of two one-step universal adhesives to dentin using different dentin-conditioning methods with etch-and-rinse mode. Ninety-six dentin specimens were randomly divided into two groups based on application of two adhesives and assigned to three subgroups according to different dentin conditioning (wet-bonding; air-dried; rewetting). After etching and rinsing, experimental dentin conditioning was conducted on the etched dentin specimens. All specimens were subjected to shear bond strength testing using a universal testing machine, and all data were statistically analyzed using two- way analysis of variance with Tukey’s post hoc test. All debonded specimens were examined for fracture pattern by scanning electron microscopy (SEM). Adjunctively, one specimen per group was prepared by the same processing and longitudinally sectioned. Then, the infiltration ability of adhesives into dentin was examined by observing the interface using confocal laser-scanning microscopy (CLSM). Wet and Rewet groups exhibited significantly higher shear bond strength than dry groups on the etch-and-rinse system, regardless of different adhesives. The bond strength between wet and rewet groups showed no significant difference in Tukey’s test. Analysis of failure surface using SEM showed that predominant failure patterns were mixed in both the wet-bonding group and dry-bonding group. CLSM presented that resin penetration into etched dentin was enhanced similarly in wet and rewet group. Application of rewetting agents on dried dentin increased the bonding performance of universal adhesives on etch-and-rinse mode.     

PVAc乳胶/改性大豆分离蛋白共混胶黏剂的制备及性能

针对大豆蛋白胶黏剂耐水性差的缺点,用尿素初步改性大豆分离蛋白（SPI）,然后与白乳胶（PVAc）共混合成了共混改性大豆分离蛋白胶黏剂。采用正交实验方法考察了大豆蛋白胶与白乳胶质量比、共混时间、交联剂质量分数、交联时间对大豆蛋白胶黏剂剪切粘接强度的影响,确定了优化配比及制备工艺条件,并在此基础上采用正交试验优化了热压参数。结果表明：大豆蛋白胶与白乳胶质量比10∶1,共混时间1h,交联剂质量分数1.0%,交联时间1.5h,热压温度120℃,热压压强1.2MPa,热压时间2min/mm,涂胶量250g/m2时,测得胶黏剂的干态剪切粘接强度为2.01MPa,按照Ⅰ类胶合板标准测得湿态剪切粘接强度为1.04MPa,并对优化配方进行了结构与性能分析。     

Comparative study on the properties of cross-linked cellulose nanocrystals/chitosan film composites with conventional heating and microwave curing

Cross-linking of chitosan film composites was carried out by using conventional heating and microwave curing methods in this study. Non-cross-linked and glutaraldehyde (GA) cross-linked neat chitosan and cellulose nanocrystals (CNC)/chitosan film composites were cured by either conventional oven heating or microwave irradiation. Tensile strength and Young's modulus of chitosan composites were enhanced significantly by the addition of CNC and GA especially for the microwave-cured samples. The changes in chemical interaction of the chitosan film composites was determined by Fourier transform infrared (FTIR) spectroscopy. The microwave-cured GA-cross-linked chitosan film composites were more thermally stable than non-cross-linked and conventionally heated GA-cross-linked chitosan film composites due to the formation of a more stable structure between GA and chitosan. Nevertheless, the reduced antimicrobial efficacy of film composites against Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae was observed in cross-linked film composites compared with non-cross-linked composites.