Synthesis,characterization, and thermal properties of copolymers of behenyl acrylate and behenyl fumarate

Radical copolymerization of behenyl (systematic IUPAC nomenclature: n‐docosyl) acrylate and behenyl fumarate has been carried out in toluene at 70°C using benzoyl peroxide as initiator. Gel permeation chromatography was used to determine molecular weights (MW) and molecular weight distribution (MWD) of behenyl acrylate–behenyl fumarate (BA‐BF) copolymers. ¹H NMR and carbon analysis was used to determine the composition of BA‐BF copolymers. Monomer reactivity ratios for high conversion polymerization were calculated by conversion‐extended Kelen‐Tudos plot. Differential scanning calorimetric (DSC) measurements shows sharp melting peaks at about 64°C. Thermal stability studies were performed with thermogravimetric analyzer (TGA). By using these DSC and TGA data in several nonisothermal methods, the activation energies were calculated. X‐ray diffraction studies show the linearity of the copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2721–2726, 2003     

Copolymers of methyl methacrylate and acrylate comonomers: Synthesis and characterization

Methyl methacrylate (MMA) has been copolymerized with n-butyl acrylate (n-BA), ethyl acrylate (EA), and 2-ethylhexyl acrylate (2-EHA) in solution at 70°C using benzoyl peroxide as free radical initiator. The copolymer composition was estimated by the ¹H-NMR spectroscopic technique. The copolymers were further characterized by IR, XRD, TGA, DTA, DSC, GPC, and solubility. The adhesive characteristics of the copolymers to cellulosic substrate are also reported. © 1995 John Wiley & Sons, Inc.     

Thermal behavior of graft copolymers of cotton cellulose and acrylate monomers

Cotton cellulose yarn was grafted with methyl acrylate, ethyl acrylate, n-butyl acrylate, and methyl methacrylate at various percentages of grafting. The effects of concentration of the initiator, concentration of the acid, and of temperature on grafting was studied and the mechanism discussed. The effect of reactivity of the monomer on the percentage graft-on is pointed out. Thermal behavior of natural and grafted cotton yarn was studied using dynamic thermogravimetry in air at a heating rate of 6°C/min up to a temperature of 500°C. The thermal stabilities of the samples grafted with various acrylate monomers to various percentages of grafting were computed from their primary thermograms by calculating the values of IDT, IPDT, and E^*. The results show that the thermal stability increases with increase in graft-on per cent, and the thermal stabilities of natural cotton and cotton grafted with different monomers are in the order ethyl > methyl > natural cellulose > methyl methacrylate > n-butyl acrylate.     

Degree of conversion and adhesion of methacrylate-based resin cements with phosphonic or phosphoric acid acrylate to glass fiber posts at different regions of intraradicular dentin

This study evaluated the degree of conversion (DC) and adhesion of methacrylate-based resin cements to glass fiber posts at different regions of intraradicular dentin. Single-rooted teeth (N?=?24, n?=?12 per group) were cut at the cement–enamel junction (CEJ), endodontically treated and post space (depth?=?8 mm) was prepared. Teeth were randomly divided into two groups according to the resin cements: (a) Group ML: methacrylate-based cement with phosphonic acid acrylate (Multilink Automix, Ivoclar Vivadent); (b) Group RXU: methacrylate-based cement with phosphoric acid acrylate (RelyX Unicem 2 Automix, 3 M ESPE). Fiber-reinforced composite root posts (RelyX Fiber Post, 3 M ESPE) were cemented according to the manufacturers’ instructions of the resin cements. Root slices of 2-mm thickness (n?=?3 per tooth) were cut below the CEJ 1, 3, and 5 mm apically. The DC of each section was analyzed with micro-Raman spectrometer and push-out test was performed in the Universal Testing Machine (0.5 mm/min). After debonding, all specimens were analyzed using optical microscope to categorize the failure modes. While data (MPa) were statistically evaluated using Kruskal Wallis, Mann–Whitney U tests for DC data 3-way ANOVA and Tukey’s tests were used (α?=?0.05). Regardless of the resin cement type, the mean push-out bond strength results (MPa), were significantly higher for the coronal slices (ML: 9.1?±?2.7; RXU: 7.3?±?4.1) than those of the most apical ones (ML: 7?±?4.9; RXU: 2.89?±?1.5) (p?=?0.002). Resin cement type and (p?p?=?0.002) significantly affected the DC values, while the interaction terms were not significant (p?=?0.606). Overall, DC was significantly higher for ML (67?±?8.2%) than RXU (26?±?8.8%) (p?相似文献   

Thermal and sonochemical degradation kinetics of poly(n‐butyl methacrylate‐co‐alkyl acrylates): Variation of chain strength and stability with copolymer composition

The thermal degradation of poly(n‐butyl methacrylate‐co‐alkyl acrylate) was compared with ultrasonic degradation. For this purpose, different compositions of poly (n‐butyl methacrylate‐co‐methyl acrylate) (PBMAMA) and a particular composition of poly(n‐butyl methacrylate‐co‐ethyl acrylate) (PBMAEA) and poly(n‐butyl methacrylate‐co‐butyl acrylate) (PBMABA) were synthesized and characterized. The thermal degradation of polymers shows that the poly(alkyl acrylates) degrade in a single stage by random chain scission and poly(n‐butyl methacrylate) degrades in two stages. The number of stages of thermal degradation of copolymers was same as the majority component of the copolymer. The activation energy corresponding to random chain scission increased and then decreased with an increase of n‐butyl methacrylate fraction in copolymer. The effect of methyl acrylate content, alkyl acrylate substituent, and solvents on the ultrasonic degradation of these copolymers was investigated. A continuous distribution kinetics model was used to determine the degradation rate coefficients. The degradation rate coefficient of PBMAMA varied nonlinearly with n‐butyl methacrylate content. The degradation of poly (n‐butyl methacrylate‐co‐alkyl acrylate) followed the order: PBMAMA < PBMAEA < PBMABA. The variation in the degradation rate constant with composition of the copolymer was discussed in relation to the competing effects of the stretching of the polymer in solution and the electron displacement in the main chain. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Initiator‐free photopolymerization of common acrylate monomers with 254 nm light

Using an available light source at a wavelength of 254 nm, common acrylate monomers were polymerized without any photoinitiators, which was confirmed using Fourier transform IR (FTIR) spectroscopy, ¹H NMR, gel permeation chromatography and fast atom bombardment mass spectrometric measurements. It was found that phenyl acrylate shows higher conversion than n‐ and t‐butyl acrylates. A trifunctional acrylate was also used for UV curing. The cured films were fabricated successfully on different kinds of substrates by using a batch‐ or conveyor‐type irradiation apparatus. It is indicated from FTIR spectral measurements that ca 40%–50% of acryloyl groups are consumed by the photopolymerization. Oxygen concentration in the sample chamber influences the photopolymerization, indicating that the polymerization proceeds via a radical process. © 2018 Society of Chemical Industry     

Noise and vibration damping with latex interpenetrating polymer networks

Damping systems based on interpenetrating polymer networks (IPN's) provide noise and vibration attenuation over broad temperature and frequency ranges. Semicompatible latex IPN's are employed in both extensional and constrained layer configurations. The damping behavior of IPN's of compositions poly(ethyl methacrylate)/poly(n-butyl acrylate) [PEMA/PnBA], poly(ethyl methacrylate–co–ethyl acrylate)/poly(n-butyl acrylate–co–ethyl acrylate) [P(EMA–co–EA)/P(nBA–co–EA)], and poly(vinyl chloride)/poly(butadiene–co–acrylonitrile) [PVC/P(B–co–AN)] were investigated and compared to both commercially available materials and to theory. The damping of both the PEMA/PnBA and the P(EMA–co–EA)/P(nBA–co–EA) IPN's in a constrained layer configuration was significantly better, over a broad temperature range of ?10° to 60°C, than the commercial materials. In addition, the P(EMA–co–EA)/P(nBA–co–EA) IPN was found to be effective in damping phenolic-impregnated Kevlar cloth laminates. A reduction of 10 dB in impact noise resulted with a 6–8% by weight layer inserted between the Kevlar-phenolic panels. The relationship between the peak damping temperature of a constrained layer system to maximum tan δ along with that of an extensional damping system to maximum E″ was also demonstrated. Although the amount of damping predicted by the theory approached that found experimentally, sufficient differences existed such that the exact detail of the damping curve was not described.     

Hydrophobically modified nanocomposite hydrogels with self-healing ability

Several strategies have been developed in the past two decades to increase the mechanical performance of the hydrogels, and to generate self-healing function within the polymer network. Here, we combine two of these strategies to create hydrophobically modified nanocomposite (NC) hydrogels with high mechanical strength and self-healing efficiency. The hydrogels were prepared by in situ copolymerization of N,N-dimethylacrylamide and n-octadecyl acrylate (C18A) in the presence of 2 w/v % Laponite clay nanoparticles in an aqueous solution of worm-like sodium dodecyl sulfate micelles. Incorporation of hydrophobic C18A segments into the gel network significantly increases both the storage and loss moduli of NC hydrogels indicating increasing elasticity and energy dissipation. An improvement in the mechanical performance and self-recoverability of NC hydrogels was also observed after hydrophobic modification. The compressive fracture stress and Young's modulus increase with increasing amount of C18A, and they become 9 ± 1 MPa and 30 ± 2 kPa, respectively, at 4 mol % C18A. Incorporation of hydrophobic segments also provides a larger energy dissipation under large strain as compared to the traditional NC hydrogels providing a self-healing efficiency of 90 ± 10% in mechanically strong NC hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48853.     

Influence of co-monomer-type and amount on thermomechanical properties of ultrafast-curing acrylic resins using a triacrylic crosslinker

An ultrafast ultraviolet-light-cured acrylic resin was developed. The monoacrylic monomers ethylene-glycol-phenyl-ether acrylate (EGPEA), 2-hydroxy-3-phenoxypropyl acrylate (HPPA), di(ethyleneglycol)-ethyl-ether acrylate (DEGEEA), or poly(ethyleneglycol)-phenyl-ether acrylate (PolyEGPEA) were each mixed with varying amounts of the triacrylic crosslinker tris[2-(acryloyloxy)ethyl] isocyanurate (ICTA). The curing time was 1 s at room temperature (average degrees of curing between 55 and 85%). The specimens of ICTA-EGPEA showed a maximum tensile strength of 76.0 ± 1.4 MPa, an E-modulus of 4216 ± 188 MPa, an elongation at break of 2.3 ± 0.1%, and a glass transition temperature (T _g) of 100 °C. The development of properties with increasing amount of crosslinker could be well described on the basis of percolation theory. Below the percolation threshold the behavior is dominated by the auxiliary co-monomer. Above the percolation threshold the behavior is dominated by ICTA. On exchanging EGPEA by HPPA, the influence of hydrogen bonding on the thermomechanical properties was extracted. Exchanging EGPEA by DEGEEA or PolyEGPEA allowed for exploring the influence of beta-relaxation of the monoacrylic monomers on the thermomechanical properties of the resin. Large ester side-groups reduced the tensile strength, the E-modulus, and the T _g decisively. The impact strength in turn was decisively increased using PolyEGPEA as auxiliary co-monomer. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47294.     

Molecular weight characterization of poly(acrylamide-co-sodium acrylate). I. Viscometry

Mark–Houwink constants for polyacrylamide and poly(acrylamide-co-sodium acrylate) in 0.2M Na₂SO₄ were measured using eight fractionated samples of polyacrylamide and 26 hydrolyzed polyacrylamide samples. The dependence of K and a on the copolymer compositions was found for the range of acrylate content 6 ～ 40 mol %. A relationship between intrinsic viscosity and acrylate content in the form of square root law was found. Molecular weights of copolymer samples with various compositions were estimated using viscometry with Mark–Houwink equations established in this work. The molecular weights of narrow MWD copolymer samples could be measured with an error of ±5%, whereas those of broad MWD copolymer samples with an error of ±8%.     

n‐Butyl acrylate based latex interpenetrating polymer networks used as processing modifiers and impact modifiers of poly(vinyl chloride)

A latex interpenetrating polymer network (LIPN), consisting of poly(n‐butyl acrylate), poly(n‐butyl acrylate‐co‐ethylhexyl acrylate), and poly(methyl methacrylate‐co‐ethyl acrylate) and labeled PBEM, with 1,4‐butanediol diacrylate as a crosslinking agent was synthesized by three‐stage emulsion polymerization. The initial poly(n‐butyl acrylate) latex was agglomerated by a polymer latex containing an acrylic acid residue and then was encapsulated by poly(n‐butyl acrylate‐co‐ethylhexyl acrylate) and poly(methyl methacrylate‐co‐ethyl acrylate). A polyblend of poly(vinyl chloride) (PVC) and PBEM was prepared through the blending of PVC and PBEM. The morphology and properties of the polyblend were studied. The experimental results showed that the processability and impact resistance of PVC could be enhanced considerably by the blending of 6–10 phr PBEM. This three‐stage LIPN PBEM is a promising modifier for manufacturing rigid PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1168–1173, 2004     

Aminolysis reaction of poly(N-4-methylphenylitaconimide) and its graft copolymerization

Polyitaconimide and copolymers of itaconimide were transformed to macromolecules having diamido pendent groups via an aminolysis reaction. The polymers obtained were cast into films, which were then graft copolymerized with acrylamide (AAM) using ceric ion as an initiator. Radical homopolymerization and copolymerization of N-4-methylphenylitaconimide with methyl acrylate or ethyl acrylate were carried out at 60°C in benzene; high molecular weight polymer and copolymers (M?_n = 10⁴–10⁵) were obtained. The resulting polymer and copolymers were reacted with n-butylamine in order to produce polymers possessing a pendent 4-tolylcarbamoyl group (4-CH₃C₆H₄NHCO-), which can significantly promote the acrylamide (AAM) graft copolymerization initiated with ceric ion. Transparent films of the polymers were graft copolymerized with AAM in the presence of ceric ion at 45°C. The formation of graft polymers was verified by water absorption percentage, XPS and SEM.     

Sequence determination of vinyl acetate–methyl acrylate copolymers by NMR spectroscopy

Vinyl acetate/methyl acrylate (V/M) copolymers were prepared by free-radical solution polymerization in benzene. Copolymer compositions were obtained from ¹H-NMR spectroscopy. Reactivity ratios for the copolymerization of V with M were calculated using the Kelen-Tudos (KT) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the KT and EV methods are r_V = 0.04 ± 0.03 and r_M = 7.28 ± 2.88 and r_v = 0.04 ± 0.01 and r_M = 7.28 ± 0.37, respectively. The microstructure was obtained in terms of the distribution of V- and M-centered triad sequences from ¹³C{¹H}-NMR spectra of copolymers. Homonuclear ¹H-2D-COSY and 2D-NOESY NMR were used to determine the most probable conformer for the V/M copolymer. The copolymerization behavior of the V/M copolymers as a function of conversion is also reported. © 1994 John Wiley & Sons, Inc.     

Characterization and Benzo[a]pyrene Content Analysis of Camellia Seed Oil Extracted by a Novel Subcritical Fluid Extraction

A novel continuous subcritical n‐butane extraction technique for Camellia seed oil was explored. The fatty acid composition, physicochemical properties, and benzo[a]pyrene content of Camellia seed oil extracted using this subcritical technique were analyzed. Orthogonal experiment design (L₉(3⁴)) was adopted to optimize extraction conditions. At a temperature of 45 °C, a pressure of 0.5 MPa, a time of 50 min and a bulk density of 0.7 kg/L, an extraction yield of 99.12 ± 0.20 % was obtained. The major components of Camellia seed oil are oleic acid (73.12 ± 0.40 %), palmitic acid (10.38 ± 0.05 %), and linoleic acid (9.15 ± 0.03 %). Unsaturated fatty acids represent 83.78 ± 0.03 % of the total fatty acids present. Eight physicochemical indexes were assayed, namely, iodine value (83.00 ± 0.21 g I/100 g), saponification value (154.81 ± 2.00 mg KOH/g), freezing‐point (?8.00 ± 0.10 °C), unsaponifiable matter (5.00 ± 0.40 g/kg), smoke point (215.00 ± 1.00 °C), acid value (1.24 ± 0.03 mg KOH/g), refrigeration test (transparent, at 0 °C for 5.5 h), and refractive index (1.46 ± 0.06, at 25 °C). Benzo[a]pyrene was not detected in Camellia seed oil extracted by continuous subcritical n‐butane extraction. In comparison, the benzo[a]pyrene levels of crude Camellia seed oil extracted by hot press extraction and refined Camellia seed oil were measured at 26.55 ± 0.70 and 5.69 ± 0.04 μg/kg respectively.     

Polymer-leather composites. I. Process and location study for the deposition of selected acrylate monomers by polymerization into chrome-tanned cattlehide

Three acrylate monomer systems were deposited by redox emulsion polymerization at room temperature into the fibrous matrix of 2-mm-thick chrome-tanned cattlehide over a wide range of composition. Polymer not bound to the matrix was separated by hot benzene extractions. Monomers used were methyl methacrylate, a mixture of n-butyl acrylate and methyl methacrylate and n-butyl acrylate, each selected to produce composites having wide variation in glass-transition temperature. The same three systems were introduced into the free space of leather by bulk and solution polymerization. All conversions were close to 100%. When the emulsion technique was used, with feed composition variable, overall deposition efficiency depended on the characteristic rate of deposition for the individual acrylate monomers. Observed orders in deposition rate and overall efficiency were: methyl methacrylate > comonomer > n-butyl acrylate. However, specific deposition efficiencies declined roughly monotonically with feed or time increase, but maintained the same order. Microscopic examination of thin sections revealed polymer only in the outer region of the leather cross section. Information on polymer location and its influence on specimen thickness for composites prepared by both emulsion and solution methods of deposition were obtained by correlating experimental densities with theoretical density–composition curves for various assumed models. The foregoing, together with observations of greatly reduced grafting frequency, in view of the maximum theoretically attainable, made a dominant grafting mechanism unattractive. A mechanism involving diffusion controlled monomer transport to occluded radicals in localized polymer deposits was suggested as an alternative.     

Amphiphilic maleic acid copolymers as corrosion inhibitors for aluminum pigment

Aluminum pigments react in aqueous alkaline media (e.g., water-borne paints) by the evolution of hydrogen. Maleic acid copolymers, which were synthesized by copolymerization of maleic acid anhydride, styrene, and acrylic esters (ethyl-, n-butyl-, n-hexyl-, n-dodecyl-, and n-octadecyl acrylate) inhibit this corrosion reaction. With the increasing chain length of the ester alcohol of the acrylate monomer, the evolved hydrogen volume decreases (i.e., the corrosion inhibiting effect increases). There seems to be a potential correlation between the number of carbon atoms of the ester alcohol of the copolymers and the evolved hydrogen volumes. With the addition of 0.5 wt % of the copolymers with n-butyl, n-hexyl, n-dodecyl-, and n-octadecyl acrylate no hydrogen evolution was observed at pH 8 within 21 days (complete corrosion inhibition). Conductivity measurements of aqueous copolymer solutions indicate that with an increasing chain length of the ester alcohol, the copolymers possibly associate by hydrophobic bonding. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2169–2174, 1998     

Preparation of poly(styrene‐b‐2‐hydroxyethyl acrylate) block copolymer using reverse iodine transfer polymerization

Reverse iodine transfer polymerizations (RITP) of 2‐h‐ydroxyethyl acrylate (HEA) were performed in N,N‐dimethylformamide at 75°C using AIBN as initiator. Poly(2‐hydroxyethyl acrylate) (PHEA) with M_n = 3300 g mol^?1 and M_w/M_n <1.5 were obtained. Homopolymerization of styrene in RITP was also carried out under similar conditions using toluene as solvent. The resulting iodo‐polystyrene (PS‐I) with (M_{n, SEC} = 607 g mol^?1, polydispersity index (PDI) = 1.31) was used as a macroinitiator for the synthesis of amphiphilic block copolymers based on HEA with controlled well‐defined structure. Poly(styrene‐b‐2‐hydroxyethyl acrylate) (PS‐b‐PHEA) with M_n = 13,000 g mol^?1 and polydispersity index (M_w/M_n) = 1.4 was obtained, copolymer composition was characterized using ¹H‐NMR and FTIR, whereas SEC and gradient HPLC were used to confirm the formation of block copolymer and the living character of polymer chains. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Control of monodisperse particle size of styrenic–acrylate copolymers in dispersion copolymerization

Syntheses of monodisperse poly[(styrene)‐co‐(n‐butyl acrylate)] and poly[(styrene)‐co‐(2‐ethylhexyl acrylate)] were carried out by dispersion polymerization. The reactions were performed in the mixed solvent of ethanol–water in the presence of azo‐bisisobutyronitrile and poly(N‐vinylpyrrolidone) as the initiator and dispersant, respectively. The effects of reaction parameters, that is the type and concentration of dispersant, ratio of the mixed solvent, reaction temperature, agitation rate, monomer composition between styrene and n‐butyl acrylate or 2‐ethylhexyl acrylate, crosslinking agent and reaction time on the particle size, size distribution and average molecular weights of the resulting copolymer were thoroughly investigated. The resulting copolymer particles were smooth on their spherical surface and the sizes were in the range 0.6–1.8 µm with a narrow size distribution. In most cases, a correlation between small particle sizes with high average molecular weights was observed. The average particle size generally increased with increasing reaction temperature, time and acrylate monomer content. In contrast, the particle size decreased as the molecular weight, concentration of dispersant, polarity of the medium or agitation rate was increased. The glass transition temperature (T_g) of the copolymers can be controlled by the mole ratio of the comonomer. The T_g values decreased when the content of acrylate monomers in the copolymer increased, and T_g values of the synthesized copolymer were in the range 66–102 °C. Instead of using n‐butyl acrylate monomer in the copolymerization, 2‐ethylhexyl acrylate copolymerization with styrene resulted in insignificant changes in the particle sizes but there were significant decreases in T_g values. In this study, the monodisperse particles can be obtained by monitoring the appropriate conditions regarding PVP K‐30 (2–8 wt%), ethanol/water (90/10 wt%), the reaction temperature (70 °C) and the agitation rate (100 rpm). © 2000 Society of Chemical Industry     

Mechanism of the polymerization of n-butyl acrylate initiated by N,N-diethyldithiocarbamate derivatives. Part 2. Investigation of the reaction mechanism

The polymerization of n-butyl acrylate (BuAc) initiated with a model compound (butyl-2-(N,N-diethyldithiocarbamyl)propionate, RTC) has been investigated. The living character of this polymerization has been assessed and compared with those of styrene and methyl methacrylate. The small variation of M_n with yield is explained by the faster propagation than for styrene and methyl methacrylate, which leads to slow initiation and extensive transfer to the initiator. Predominant reversible termination (or deactivation) of the growing chains by the dithiocarbamyl radicals gives, however, polymers of functionality near to unity, which are photoinitiated at the same rate as RTC and reinitiate the polymerization of BuAc with a linear growth of the M_n up to 40% yield. This is better than was obtained with methyl methacrylate. Side reactions also take place leading to a decrease of functionality, to the formation of tetraethylthiuram disulphide and of carbon disulphide. Possible mechanisms are proposed for the secondary reactions. © 1998 SCI.     

Contact Time and Temperature Dependencies of Tack in Polyacrylic Block Copolymer Pressure-Sensitive Adhesives Measured by the Probe Tack Test

The adhesion strength of an adhesive is affected by two factors: the development of interfacial adhesion and the cohesive strength of the adhesive. In order to evaluate the relative contributions of these two factors, the tack of polyacrylic block copolymer-based adhesives was measured using a probe tack test. For this purpose, three model adhesives were prepared: poly(methyl methacrylate)-block-poly(n-butyl acrylate)-block-poly(methyl methacrylate) triblock copolymer (A), a mixture of the triblock and poly(methyl ethacrylate)-block-poly(n-butyl acrylate) diblock copolymer (7/3, w/w) (B), and a mixtureof the triblock and poly(n-butyl acrylate) oligomer (8/2, w/w) (C). The tack measured at room temperature was in the order B ≈ C > A and increased gradually with an increase in the contact time. The temperature dependence of tack showed peak tack values above room temperature, and the peak tack temperature was in the order A > B > C. The storage and loss moduli measured by dynamic mechanical analysis were also in the order A > B > C. The molecular mobility of the poly(n-butyl acrylate) unit in the block copolymer measured by H-pulse NMR was in the order C> B > A. It was concluded from these results that the relative contribution of interfacial adhesion to the tack of the different systems was in the order C > B > A.