This paper assesses methods for the fabrication of single-sided electrically conductive tape. Silicone resin, dichlorobenzoyl peroxide, and various types of carbon fillers were used to prepare ...pressure-sensitive adhesives. Various carbon black and graphene filler concentrations in the range 1 to 25 wt.% were tested, whereas for carbon nanotubes the range was 0.25 to 10 wt.%. The adhesion, shear strength, tack, and shrinkage of the prepared tapes were determined. The most important property of the resulting tapes is their electrical conductivity. By using carbon black as a filler, it was possible to obtain a conductivity of 4.3 × 10
−3
S/m, with carbon nanotubes 1.4 × 10
−01
S/m and with graphene 5.9 × 10
−3
S/m. Such electrically conductive silicone self-adhesive tapes are not yet commercially available on the market, but are expected to be useful in the electronic industry for the bonding of various materials. In the available literature provides no information about the self-adhesives tapes based on silicone pressure-sensitive adhesices which exhibit electrically conductive properties.
It is important to develop research on sealing materials in order to find effective solutions to ensure the energy efficiency of buildings. The aim of this study is to investigate the peel adhesion ...of single-sided self-adhesive tapes to different construction surfaces and to determine the change in this characteristic due to climatic effects. Different construction tapes, mostly used externally in buildings, are glued to different substrates. The artificial aging of test samples was carried out, simulating the effects of moisture, heat, and cold; the intensity, duration, and sequence of the cyclic effects were determined, taking into account the statistical climatological data of the middle-latitude climate zone. The peel adhesion of the tapes was determined before and after different numbers of artificial aging cycles. The results show that the peel adhesion range is very wide, from 11 to 61 N/24 mm. In most cases, a lower-rated peeling adhesion was obtained by peeling the tape from plastered cement–sawdust board. The change in peel adhesion depends more on the surface to which the tape is glued than it does on the number of climatic exposure cycles selected for the test.
Hydrocarbon resins, which are defined as low molecular weight, amorphous, and thermoplastic polymers, are widely used as tackifiers for various types of adhesives, as processing aids in rubber ...compounds, and as modifiers for paint and ink products, and for use in plastics polymers such as isotactic polypropylene. Recently, the quantities of the hydrocarbon resin׳ raw materials which are the side products from naphtha cracking process have decreased because of light-feed cracking such as gas cracking, so new raw materials for hydrocarbon resin production are essential. To be satisfied with the previously mentioned factors, the substitution of hydrocarbon resin raw materials with renewable resources is a worthy consideration. Moreover, new hydrocarbon resin having high adhesion performance, low specific gravity, and good compatibility with various polymers has been requested in various adhesives.
To meet those requests, in this study, propylene instead of side product from naphtha cracking as main raw material of hydrocarbon resin were partially used. The propylene serves as a new, sustainable raw material and was successfully grafted onto dicyclopentadiene. The reaction of the propylene with dicyclopentadiene was confirmed because, according to NMR and FT-IR analyses, a pendant methyl-propylene group exists in the structure of the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin. To establish an optimal production condition regarding the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin, numerous experiments were conducted according to the mole ratio of the raw materials and the polymerization temperature. The propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin that was manufactured according to optimal conditions results in a lower specific gravity and a high molecular weight, whereby the advantages of the adhesion properties of an SIS-based pressure-sensitive-adhesive are exploited. When the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin was formulated with the SIS-based pressure-sensitive-adhesive, both the heat stability and the shear-adhesion strength are sound.
A novel application of a biodegradable polysaccharide-based film as a pressure-sensitive acrylic adhesive carrier has been reported. For film preparation carboxymethyl derivatives of starch (CMS) and ...cellulose (CMC) have been used. Based on physicochemical tests results (solubility in water, moisture absorption, mechanical properties) the most promising CMS/CMC 50/50wt% film was selected as a carrier for an acrylic pressure-sensitive adhesive tape. Prepared double-sided self-adhesive tapes were characterized by good tack 5N/2.5cm, peel adhesion 12N/2.5cm and shear strength 90N/6.25cm2 at 20°C. Such acrylic self-adhesive tapes could find application in the paper industry.
•Based on the MAH concentrations used in this work – 1.5%, 2.5% and 3.0% – the degree of grafting increased with MAH loading, that translated to improved adhesion up to a maximum then decreased.•At ...3.0% MAH loading, the reduced flowability of the adhesive that was found to be detrimental to good wettability and homogenous spread of adhesive over the pipe surface during the coating process and reduced adhesion.•It was observed that a finer particle size ≤300μm would produce a higher peel adhesion strength than ≥300μm.•Shorter interval times were found to be overall advantageous for adhesion performance.
Polyethylene (PE) adhesives used in combination with a PE topcoat and a fusion bonded epoxy (FBE) are one of the most common pipeline corrosion-resistant coating systems used in the oil and gas industry. The role of the adhesive in binding the topcoat to the steel surface is critical to ensuring long term protection against corrosion attack to the pipeline. Consistent with this, it is important to understand how adhesion is optimised by controlling the physical and chemical properties of the adhesive. In this work, adhesives were produced by grafting maleic anhydride (MAH) on to the polymer backbone of an inert polyethylene via free radical chemistries during reactive processing then investigating adhesive performance as function of grafting. The effects of particle size on adhesion performance were also studied for two mean particles sizes of 300μm and 125μm. Overall, increasing MAH (along with increasing DBP) concentration enhanced the degree of grafting, as characterised by FTIR spectroscopy, which in turn resulted in enhanced interfacial interaction between the non-polar PE topcoat and polar FBE. However, an intermediate level of MAH was found to produce the greatest adhesion due to a subsequent increase in viscosity, as shown by changes in the melt flow index (MFI) and reduced wetting of the adhesive to the primer at higher MAH concentrations. Thermal analyses using Differential Scanning Calorimetry (DSC) confirmed that functionalization of the PE adhesive disrupted its semi-crystalline structure by reducing melting temperature (Tm) and degree of crystallinity (Xc). Investigation of the effects of particle size and coating interval time revealed that finer particle sizes of ≤300μm produced further improvement in adhesion strength compared to the coarser particles size ≥300μm, while longer interval times degraded the adhesion performance of the coating system. This finding suggests that, apart from grafting efficiency, selection of particle size and coating times are important considerations for achieving optimum coating adhesion performance in three‐layer PE coating systems.
In this study, we investigated the influence of the addition of MgO powder to the alkali and alkaline-earth borosilicate (AEB) glass paste on acid durability and peel adhesion characteristics of Ag ...conductors formed on the alumina substrate with the AEB glass paste. It was determined that the addition of the MgO powder to the AEB glass paste promoted crystal precipitation during the firing process of the printed AEB glass thick-film on the substrate at 850 °C. By characterizing the acid corrosion behavior in a H2SO4 aq., the weight loss after immersion for the micro-crystallized AEB glass thick-film with the added MgO powder was reduced by approximately half compared with that of the AEB glass thick-film without the MgO powder. In addition, no cracks were observed on the film surface of the micro-crystallized AEB glass, whereas cracks appeared on the film surface of the non-crystallized AEB glass after the acid corrosion treatment. It is thought that micro-crystallization induced by the addition of MgO powder to the glass paste during the firing process is partly involved in improving the acid resistance of the AEB glass thick-film. During the peel adhesion test of the Ag conductor on the alumina substrate in a H2SO4 aq., the Ag conductor formed with the MgO powder-added AEB glass paste exhibited small deterioration of peel adhesion in comparison to the Ag conductor formed using the AEB glass paste without the MgO powder. These results suggest that the correlation between the improved acid durability and peel adhesion characteristics of the Ag conductor formed with the MgO powder-added AEB glass paste was related to the micro-crystallization of the AEB glass induced by the addition of MgO powder to the thick-film pastes during the annealing process at 850 °C.
Electrical conductive pressure-sensitive adhesives (PSAs) are not commercially available on the market. The development of these PSAs requires special suitable self-adhesive polymers and their ...modification through adding of electrical conductive fillers. From the evaluated PSAs the best performances were achieved using acrylic PSAs. Common fillers for electrical conductivity are carbon nano-fillers, metallic powders like copper, aluminum, nickel, silver or gold. Acrylic PSA containing electrical conductivity fillers are applied for the manufacturing of diverse technical self-adhesive products, such as broadest line of electrically conductive sensitive double-sided, one-sided and carrier-free tapes. After addition of electrical conductive fillers the main typical properties for pressure-sensitive adhesives like tack and peel adhesion are deteriorated. In the last time the research and development on the area of nano carbon black or nanotubes as electrical conductive fillers is observed.
Plant oils are attractive renewable feedstocks for biobased pressure-sensitive adhesives (PSAs). In this study, we investigated how the PSA adhesion properties were influenced by the compositions ...comprised of epoxidized soybean oil (ESO), 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (ECHM), dihydroxyl soybean oil (DSO), rosin ester, and cationic photo initiator. When the amounts of ESO and photo-initiator were constant, the variables of ECHM, DSO, and rosin amounts and their interactions were significant in influencing PSA peel adhesion strength, with
p
values smaller than 0.05 under a 95% significance level. Rosin amounts with the largest coefficient of 0.94 compared to the other variables are the most determinant factors. The peel adhesion strength was higher when using relatively a lower level of ECHM and a higher level of ESO and rosin. A model with the coefficient of determination (
R
2
) of 95.06% was obtained to describe the relationship between the amount of resin constituents (ECHM, DSO, and rosin) and PSA peel adhesion strength in the experimental variable ranges. The optimal PSA formulation without cohesive failure was (ECHM = 0.04, DSO = 0.7, rosin = 0.7), resulting in a peel adhesion strength of 4.45 N/in. Structure–property relationships of the PSAs were established via thermal and rheological studies.
UV crosslinking technology is well established in the market and allows the production of a wide range of UV-crosslinkable pressure-sensitive adhesives (PSA) based on acrylics with interesting ...performance. The balance between adhesive and cohesive strengths after the crosslinking process is very important and critical for the properties of acrylic PSAs in the form of self-adhesive layers. The cationic UV-crosslinking of an acrylic PSA containing oxirane groups in the structure and additionally with the cationic photoinitiator 1,10-bisN,N’-(2-methylbenzothiazolium)decane diiodide, designed to promote properties such as tack, peel adhesion and shear strength of self-adhesive polymer layers, has been investigated using a UV-lamp as an ultraviolet source. An acrylic PSA synthesized from 55wt% of butyl acrylate, 30wt% of 2-ethylhexyl acrylate and 15wt% of glycidyl methacrylate was studied. The application of 1,10-bisN,N’-(2-methylbenzothiazolium)decane diiodide as a photoreactive crosslinker allows the manufacture of high quality PSA products with interesting properties, such as high tack, high peel adhesion, and excellent shear strength.
A synthesis of acrylic microsphere pressure sensitive adhesives with addition of nanocellulose filler is presented. In the first stage α cellulose was modified by acid hydrolysis and the produced ...nanocellulose suspension was added into the continuous phase of a suspension polymerization reaction mixture. The amount of nanocellulose varied in range from 0wt% (reference synthesis) to 5wt% calculated on monomer amount. The first part of the study was assigned to the characterization of the synthesized adhesive suspension. Particle sizes and particle size distributions were measured. Then, adhesives were coated via a transfer coating process and adhesive properties were evaluated. Additionally, polymer glass transition temperatures were determined and due to significant differences in measured adhesive properties, adhesive viscoelastic properties were examined using dynamic mechanical analysis (DMA). Results showed that it's possible to use nanocellulose as a nanofiller in microsphere adhesives. Suspensions were stable, mean particle sizes decreased with increasing nanocellulose content mainly due to a higher continuous phase viscosity. Adhesive properties testing revealed non typical behavior for the nanocomposite microsphere PSA material. All three measured adhesive properties increased with increasing nanocellulose content. A synergistic effect of lower particle sizes along with hydrogen bonding exhibited an increase in adhesive properties. DMA analysis showed that the storage modulus (G') increased with increasing amount of added nanocellulose. At the same time a decrease in maximal tan δ values was observed which concurred with improved cohesivity, hence higher shear strength.
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