Zirconium-based coupling agents and adhesion promoters

The use of zirconium compounds as coupling agents is reviewed, with particular emphasis on their use in flexographic and gravure inks. The modes of action favoured by zirconium compounds are, firstly, reaction with carboxyl groups and, secondly, reaction with hydroxyl groups. Usage of zirconium compounds is increasing in application areas such as inks, adhesives, and paints.     

Evaluation of adhesion strength,flammability, and degradation of HBCD‐containing polyurethane adhesives

In this work, moisture curable flame retardant HTPB‐based polyurethane adhesives were synthesized. The influence of HBCD (Hexabromocyclododecane) as flame retardant on adhesion, degradation and change in flammability of synthesized HTPB‐based polyurethane has been studied. Relationship between phase separation in hard and soft domains and adhesion has also been investigated. FTIR analysis was used to determine phase separation in synthesized adhesives. Lap shear test was used to determine adhesion properties of adhesives applied on aluminum and glass substrates. Thermal Gravimetry analysis and Limited Oxygen Index (LOI) tests were carried out on flame retardant adhesives to evaluate effect of HBCD on degradation and flammability. Addition of HBCD to adhesives leads to reduction of thermal stability and lap shear strength for all substrates, in spite of flame retardant adhesives show higher LOI value. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚氨酯木器漆脱壳的原因分析及防治方法

主要阐述了引起溶剂型聚氨酯木器漆漆膜脱壳的影响因素与防治措施。     

环保型聚氨酯防水涂料研究进展

从多角度综述了聚氨酯防水涂料在适应环保要求方面的一些研究进展,并指出纳米改性是环保型聚氨酯防水涂料发展的方向之一。     

Use of silanes and copolymers as adhesion promoters in glass fiber/polyethylene composites

Two organofunctional silanes and three functionalized copolymers were used as adhesion promoters in glass fiber/polyethylene‐reinforced composites. The performance of the coupling agents was investigated by mechanical property measurements, scanning electron microscopy, and dynamic mechanical analysis. Coupling achieved with the poly(ethylene‐g‐maleic anhydride) copolymer proved to be the most successful compared with the other copolymers (ethylene/vinyl alcohol, ethylene/acrylic acid) and silane agents (γ‐methacryloxypropyltrimethoxy, cationic styryl). The combined coupling performance of the silanes and copolymers examined in this study appears to be controlled by the coupling performance of the copolymer. Effective coupling was reflected in increased mechanical properties. Increased fiber/matrix adhesion is not always associated with effective coupling because structural changes occurring at the interface region can result in a deterioration of the material property. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2877–2888, 2001     

Phenol‐modified polypropylenes as adhesion promoters in glass fiber–reinforced polypropylene composites

This publication is based on research work done on functional phenol‐modified polypropylenes (PPs) as adhesion promoters in glass fiber–reinforced PP composites. The glass fiber roving was first impregnated with different combinations of functional polymers and polypropylene in a melt impregnation die attached to an extruder to obtain prepreg. The prepreg was then tested in many ways both macro‐ and micromechanically. The tests included notched tensile tests, optical and electron microscopy, and DMTA (dynamic mechanical thermal analyzer) and DSC (differential scanning calorimetry) analyses as well as determination of the glass content. The tests were run on prepregs containing pure PP, PP with a commercial adhesion promoter, and PP with a number of functional, mostly phenol‐based, polymers. Also, single‐fiber tests were performed on individual glass fibers to test the level of adhesion with the above‐mentioned material combinations. With these tests it could be seen that some of the phenol‐based functional polymers provided the prepreg with better adhesion between the fibers and the matrix than did the commercial adhesion promoter. Optical and electron microscopy also were used in determining the level of adhesion as well as the deformation and fracture mechanisms of the prepreg. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1203–1213, 2002; DOI 10.1002/app.10441     

Characterization of adhesion performance of topcoats and adhesion promoters on TPO substrates

Adhesion of organic coatings to thermoplastic olefin (TPO) substrates in automotive applications has been an issue for makers of automotive parts since TPO was first used in exterior applications, primarily fascia. A widely used technique for assuring paint adhesion to TPO is the use of adhesion promoter primers based on chlorimated polypropylenes (CPO). Much research has been focused on understanding the forces involved at the interfaces of substrate, adhesion promoter, and topcoats resulting in the adhesion or the loss of adhesion in various environmental conditions. This study correlates the adhesion performance of CPO and nonchlorinated adhesion promoters (NCPO) as measured by peel strength with properties observed through microscopy techniques. Adhesion performance of CPOs, NCPOs, and blends are quantified through the use of 90° and 180° peel strength studies. Surface characteristics of adhesion promoters applied over a TPO substrate and cured at various temperatures are examined through the use of atomic force microscopy (AFM).     

溶剂型聚氨酯鞋用胶的合成

研究了溶剂型聚氨酯鞋用胶粘剂,探索了合成的最优工艺条件,并进行了性能测试。胶粘剂采用PBA2000、BDO、TD180／20在溶剂丁酮下合成预聚体。最优条件为:扩链剂BDO与PBA摩尔比为0．4,异氰酸酯指数R控制在0．98-0．99范围,丁酮为首选溶剂,以二乙烯三胺和二丁基二月桂酸锡作复合催化剂,反应温度为75-85℃,反应时间为3h。合成的溶剂型聚氨酯胶粘剂具有良好的剥离强度和综合性能,添加(0．2-0．3)％的固化剂JQ-6能提高胶粘剂的最终剥离强度(20-30)％。     

双组分聚氨酯鞋用胶粘剂

研制出一种具有较高初粘性的双组分胶粘剂,并对其配比、涂胶时间和温度、涂胶次数等影响粘结强度的因素进行了研究,找到其适宜的配比为ω(A):ω(B)=100:5～10(最好为100:7～8),活化条件40℃～60℃,活化时间10min～15min。在此条件下,该胶粘剂对各种鞋用材料的粘合均显示出较高的初粘性(剥离强度大于100N/2.5cm)及终粘力。用此胶粘剂进行帮底粘接后,其剥离强度在1h内即达国标GB1002的要求。     

水性聚氨酯胶粘剂进展

介绍了水性聚氨酯胶粘剂的发展沿革 ,并就水性聚氨酯的制备方法、应用领域和发展动向作了论述。     

Swelling and adhesion characteristics of lignin-filled polyurethane sealant

Previously, polyurethane (PU)-lignin polyblend sealants from the point of view of adhesion to various substrates, morphology based on scanning electron microscopy, and miscibility based on differential scanning calorimetry (DSC) and ¹³C nuclear magnetic resonance (NMR) were studied. In this study the same polyblends together with PU filled with a few mineral fillers were used. Swelling tests were applied to establish the number average molecular weight between crosslinks of the PU and to assess the degree of interaction between various fillers including different types of lignin and the PU matrix. Lignins were found to restrict less the degree of swelling of PU than that by the Sillitin (siliceous clay)-Titanox TiO₂ 3.17: 1 wt/wt mixture. Data based on the swelling method show that lignins do not interact with the elastomer matrix to as great an extent as Sillitin/Titanox filler mixture, a finding which is in good agreement with the former DSC and NMR results.     

Organofunctional silanes as adhesion promoters: direct characterization of the polymer/silane interphase

Organofunetional silanes can be used as coupling agents to promote the adhesion of organic matrices to inorganic substrates. Silane coupling agents are of the general structure YSi(OR)₃, where Y is an organofunctional group selected for bonding to organic polymers while (OR) is a hydrolyzable group on silicon which can react with surface hydroxyl groups on the substrate. One mechanism of adhesion promotion by silanes has been postulated to be the interdiffusion of the coupling agent and the polymer to form an interpenetrating network. This paper reviews some earlier results using X-ray photoelectron spectroscopy to probe the polymer/silane interphase region and gives new results obtained using the technique of sputtered neutral mass spectrometry (SNMS). It was demonstrated that SNMS had the sensitivity necessary to detect the polymer/coupling agent interphase. It was found that interdiffusion of the coupling agent with the polymer was maximized when the solubility parameters of the polymer and coupling agent were matched.     

消防水带用聚氨酯胶黏剂的研制

采用具有较高结晶性的聚酯多元醇,以及合适的扩链剂和异氰酸酯为原料制备高初粘强度的消防水带用聚氨酯胶黏剂,并且分析了聚酯多元醇种类及数均相对分子质量(n)、扩链剂种类及用量、异氰酸酯指数(R)、纳米白炭黑及水解稳定剂对聚氨酯胶黏剂性能的影响。实验结果表明,采用n为3000左右的聚己二酸1,4-丁二醇酯,扩链剂采用1,4-丁二醇,R取1.02～1.03,并且加入经过表面改性的纳米白炭黑TS-720,加入0.5%～0.7%(与聚酯的质量比)的水解稳定剂,反应后得到的聚氨酯胶黏剂具有较高的初粘强度、较好的耐水解性能和耐老化性能。     

Thermal resistance of polyurethane adhesives containing aluminum hydroxide and dealkaline or alkaline lignin

For the sustainability of the polyurethane resin (PUR) industry, petroleum-based materials must be replaced with renewable resource and economic aspects must be considered. Lignin is a renewable, thermostable biomass consisted with a phenolic polymer. As a thermostable bio-filler for PUR adhesives, acidic or basic lignin was blended with an amphiprotic inorganic filler, to reduce the resins and product costs due to cheap, unmodified materials. The thermal resistance of the PUR adhesives was evaluated by measuring adhesion before and after heating and with and without a mechanical effect caused by substrate penetration. The results show that after heating at 200°C, the PURs containing 7.5 or 15 wt% of dealkaline lignin or 7.5 wt% of alkaline lignin decomposed more slowly than the lignin-free PUR. The properties of the PURs were also analyzed using Fourier-transform infrared spectroscopy and differential scanning calorimetry. Additionally, the PURs containing over 30 wt% of dealkaline lignin show potential as environmentally friendly water-blown PUR foams.     

Halogenation of styrene-butadiene rubber to improve its adhesion to polyurethanes

Halogenation of styrene-butadiene rubbers has been carried out using solutions containing different amounts (0.1-5 wt%) of trichloroisocyanuric acid in butan-2-one. The treated rubber surface showed increased peel strength in joints made with polyurethane adhesive. The effects of chlorination on the rubber surface were studied using scanning electron microscopy, contact angle measurements, and infrared spectroscopy. It was shown that cracks appear in the rubber surface after halogenation, a factor which favours adhesion; the larger the amount of trichloroisocyanuric acid used, the larger the number of cracks. On the other hand, chlorination of the carbon double bond (butadiene) and the formation of carboxylic acid groups seem to be the most important chemical changes in the chlorinated rubber surfaces. Chlorination increases the surface energy of the rubber, although this increase is a function of the rubber composition. In fact, for a simple rubber formulation, the polar component of the surface energy increases for the highest concentrations of chlorine on the rubber surface; but for rubber with a more complicated formulation, the same value of surface energy after chlorination was obtained, independently of the amount of trichloroisocyanuric acid added. A good correlation was found between the contact angle measurements, the infrared spectra, and the peel strength values.     

预热温度及硫化时间对丁腈橡胶粘合性能的影响

生产工艺对丁腈橡胶粘合性能有一定的影响。本文用实验模拟生产过程,通过测试粘合强度和附胶率,研究了预热温度及硫化时间对丁腈橡胶粘合性能的影响。结果表明,预热温度在90℃以下对粘合性能没有影响,高于90℃时,粘合强度随温度升高而降低;硫化时间在4h以内不影响粘合,长于4h会对粘合强度产生影响。     

New heat-resistant polytriazole adhesives: investigation of adhesion of polytriazole resins to metals

Crosslinkable polytriazole resins (CPTs) were synthesized by 1,3-dipolar cycloaddition reaction between azide and alkyne monomers. Adhesion properties of CPTs and an epoxy resin to different metal substrates (copper, iron and aluminium) were evaluated in terms of the tensile lap shear strength. CPTs to aluminium and iron substrates have higher adhesion strength than those to copper substrates. The effect of temperature and humidity on adhesion strength has been investigated. The resin CPT-3 has the best heat resistance among CPTs, whose retentions of adhesion strength are approximate 80% at 150?°C and 70% at 180?°C to all the substrates. CPTs have high adhesion properties at high temperature and humidity as compared with an epoxy resin.     

改性环氧底胶对不锈钢与聚氨酯橡胶粘接的影响

研制出改性环氧胶粘剂作为底胶用于不锈钢与浇注型聚氨酯橡胶的粘接。试验结果表明,该胶粘剂具有较高的粘接强度,粘接处经受０￣４．３ＭＰａ的循环水压测试而无漏水现象发生,满足了技术要求并通过了应用验证试验。     

Scanning probe microscopy study of dynamic adhesion behavior of polymer adhesive blends

Scanning Probe Microscopy (SPM) has been utilized to study the adhesive behavior of a blend of poly(ethylene propylene) (PEP) and the n-butyl ester of abietic acid. This blend is a model for a pressure sensitive adhesive (PSA). Force-distance measurements with simultaneous X-modulation gave information on both lateral and normal force during loading and unloading. This was a key advantage of the approach. The mechanism of adhesive failure has been elucidated by comparing the dependence of pull-off force (F_pull-off) and oscillating lateral force (F_lateral) on velocity of loading/unloading and by studying the change with velocity in the loss of effective contact area during debonding. Change in contact area with time was inferred from change in the rms lateral force. The velocity dependence of F_lateral indicates that its magnitude is strongly influenced by both contact time and the presence of tackifier. In contrast, the velocity dependence of F_pull-off is controlled by both the loading and unloading processes. While the adhesive behavior of the polymer (PEP) was mainly controlled by chain stretching during the unloading process, the adhesive performance of the tackifier enriched surface (PEP/60) was determined by the loading process at 10-50 nm/s loading velocity and by the unloading process at 100-1000 nm/s velocity.     

松香在聚氨酯涂料中的直接应用

研究了把松香直接并入NCO/OH型双组分聚氨酯涂料的羟基组分中的技术可行性,探讨了配方设计、助剂应用及漆膜固化机制。与松香在聚氨酯涂料中的其他应用途径相比,该方法具有节能减废、降低成本的优点。