Development of polymer films and its application on leather surfaces

Ten different formulations are prepared with a urethane acrylate oligomer in combination with two monofunctional monomers (EHA with low T_g and NVP with a carboamide group) and a difunctional acrylate monomer (TPGDA) in the presence of a plasticizer. Polymer films are prepared with these formulated solutions under UV radiation. Their properties (gel, hardness, tensile characters, etc.) are determined. These solutions are coated on leather substrates and cured under UV radiation. The improvement of quality of leather is manifested through the enhancement of tensile strength and elongation of the coated leather. The coating also imparts high gloss on the leather surface as well as high wear resistance. It also protects the leather from the damage of weathering effect. The best formulation is determined to be the one containing NVP with a carboamide group and a plasticizer. © 1996 John Wiley & Sons, Inc.     

Upgrading of wet blue leather surface by UV cured coating

Different formulations were developed with aromatic-based urethane acrylate and reactive diluents. The diluents were N-vinyl pyrrolidone and tripropylene glycol diacrylate. Wet blue leather surface was coated with these solutions and cured under UV radiation. Improvement of surface properties such as gloss, abrasion tear, and tensile properties was determined. Effects of different co-additives such as ethylhexyl acrylate, methylacrylate, ethylacrylate, plasticizer, etc. were investigated. Films prepared with these solutions under UV radiation were characterized. It was observed that the best formulation that induced improved properties to the wet blue leather surface was the one that contained the pyrrolidone monomer. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 11–18, 1997     

Curing of crust leather by ultraviolet radiation with urethane acrylate: Role of pigment

Eight different formulations were developed with four diacrylate reactive monomers such as tripropylene glycol diacrylate (TPGDA), 1,4‐butanediol diacrylate (BDDA), 1,6‐hexanediol diacrylate (HDDA), and 2‐ethylene glycol dimethacrylate (EGDMA) and aromatic urethane diacrylate (M1100) in order to modify the crust leather surface. To study the effect of pigment on the performance of ultraviolet (UV)‐cured leather surface, 1% pigment (congored) was incorporated in the formulations. Irgacure 369 (2%) was also used in the formulation as photoinitiator. The gel content, tensile strength, elongation at break, and pendulum hardness of UV‐cured thin films with and without pigment was studied. The films without pigment produced better properties. Among all the diluents, BDDA‐containing films showed the best performance. Different properties of UV‐coated leather surface such as pendulum hardness, tensile strength, elongation, gloss (at 20° and 60°), adhesion, and abrasion were studied. Effect of gloss on simulating weathering was also performed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 692–697, 2002     

Improvement of Leather Surface by UV Curing

Leather surface has been modified with UV-cured film of urethane triacrylate in the presence of variable concentrations of mono-functional monomers such as N-vinyl pyrrolidone (NVP) and ethyl hexyl acrylate (EHA). Incorporation of small amounts of plasticizer into the formulation has substantially enhanced both tensile strength and elongation of the coated leather. Addition of a difunctional monomer such as tripropyl glycol diacrylate (TPGDA) to the system has increased the tensile property further.     

Mechanical properties study of photocured paperboard surface treated with aliphatic epoxy diacrylate

In order to improve the quality of paperboard (a well‐known packing material) surface by photocuring method, different formulations were developed with aliphatic epoxy diacrylate (EA‐1020) oligomer along with reactive monomers of various functionalities. The reactive monomers are tripropylene glycol diacrylate (TPGDA), a difunctional monomer, and trimethylol propane triacrylate (TMPTA), a trifunctional monomer. 2‐Benzyl‐2‐dimethylamino‐1(4morpholinophenyl) butanone‐1 (Irgacure 369), a photoinitiator (2%), was incorporated into the formulations to initiate photocuring reaction. The formulated solutions were coated on clean glass plate and irradiated under UV radiation of different intensities. Different physical properties like pendulum hardness and gel content of the cured films were studied. The formulation containing TMPTA showed better properties. After characterization of the films, these formulations were applied on paperboard surfaces and cured under the same UV radiation. Various physicomechanical properties such as pendulum hardness, tensile properties, surface gloss, adhesion, abrasion, and water uptake were studied. The best performance was obtained at 12 passes of radiation with 18% TMPTA‐containing formulation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1774–1780, 2003     

Optimization of a UV-curable acrylate-based protective coating by experimental design

The influence of composition and processing parameters controlling the properties of UV-cured films was studied by the screening and quantification tools of experimental design methodology. Various formulations including acrylated prepolymers based on a polyurethane or a bis-phenol A core were blended with mono- and difunctional reactive diluents, isobornyl acrylate and hexanediol diacrylate, respectively. The influence of photo-initiator content and UV-dose were examined in experiments combining the different factors. The approach allowed formulating on rational bases a reactive blend yielding a coating exhibiting sufficient elasticity without exhibiting tackiness by blending the two types of prepolymers. An optimal domain of composition was defined by implementing a Scheffé's mixture design.     

Influence of Codiluent on the Properties of Radiation-Cured Films

A number of formulations were developed using urethane diacrylate oligomer in combination with a series of monofunctional and multifunctional reactive diluents possessing diverse glass transition temperatures from ?50°C to 250°C. Films prepared with these formulations were cured under ultraviolet (UV) radiation; their properties, such as hardness, gel content, tensile characteristics, etc., were determined and compared with those of the films cured by electron beam (EB) radiation. Effect of comonomer diluents was investigated in these cases. A good correlation was observed between these properties and the glass transition temperature (T _g) of the copolymer (cured film), prepared under radiation with urethane acrylate, monomer, and comonomer.     

Weathering and Thermal Aging of Ultraviolet-Cured Polymer Films

Six different formulations were developed with an urethane acrylate oligomer (Ebcryl 264) in combination with a carboamide monomer (N-vinyl pyrrolidone) and a difunctional acrylated monomer (tripropylene glycol di-acrylate) in the presence of some filler (talc) and a plasticizer (diallyl phthalate). Thin polymer films prepared out of these formulations under ultraviolet radiation were characterized. The change of optical absorption of these films between 240 and 380 nm as a result of weathering and thermal aging was studied. The absorption spectra shifted toward higher wavelengths for thermal and weathering treatments. Loss of tensile strength (T _s) and elongation (E _b) was also investigated. The loss was observed to be dependent on the nature of formulations.     

Effect of fillers on curing of wood surfaces with polyester oligomers by ultraviolet radiation

A set of formulations was prepared with polyester acrylate (oligoester M‐9050) oligomers in combination with reactive diluents of different functionalities such as ethylhexyl acrylate, tripropylene glycol diacrylate , and trimethylol propane triacrylate (TMPTA). The thin films were prepared with these formulated solutions under UV radiation on a glass plate, and their physical properties such as pendulum hardness and gel content were studied. The formulation containing TMPTA showed the greatest pendulum hardness and gel content. The polished wood surfaces were cured with these formulated solutions. Physical properties such as pendulum hardness gloss at 20° and 60° angles, adhesion, abrasion resistance, and scratch hardness of UV‐cured surfaces of the wood were characterized. The formulation containing TMPTA had the best physical properties. Two types of filler, sand and talc, were used in the base coat to obtain these better properties. Both fillers improved the properties; however, the 1% sand– and 4% talc–containing formulations performed better. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3826–3834, 2003     

Improvement of jute fiber through ultraviolet-cured films of urethane acrylate

Formulations were developed with urethane acrylate in combination with different monomers. The role of plasticizers used as coadditives in the formulations was investigated. Physical and mechanical properties of the UV-cured films were studied. Hessian cloths made with jute fibers were coated with these formulated solutions and cured under UV radiation. Though plasticizers decrease the tensile properties of the UV-cured films, but they substantially enhance both tensile strength by 80% and elongation of the coated hessian cloths by more than 300%. Uptake of water and moisture at different relative humidity conditions decreases significantly by the hessian cloths when coated with these formulations. © 1994 John Wiley & Sons, Inc.     

Ultraviolet curing of epoxy coating on wood surface

Different formulations were developed with EB-600 (Ebcryl-600), an epoxy acrylate oligomer in the presence of N-vinylpyrrolidone and trimethylol propane triacrylate. Thin films were prepared with these formulated solutions under ultraviolet (UV) radiation. These solutions were coated on a low-grade wood substrate (simul) and cured under UV light. Both UV-cured thin films and surface coatings were characterized, and the best formulations for coating wood surface were evaluated. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1997–2004, 1997     

Graft Copolymerization of Urethane Acrylate on Hessian Cloth (Jute) by UV Radiation

Ten different formulations were developed with urethane acrylate oligomer in combination with a number of functional monomers in the presence of additives, fillers, and plasticizers. Polymer films were prepared with these formulations under ultraviolet (UV) radiation. Physical and mechanical properties of these cured films were studied. Hessian cloths of jute fibers were coated with these formulated solutions and irradiated under UV radiation. Physical and mechanical properties of both treated and untreated hessian cloths were determined. Loss of tensile properties of the samples by weathering treatment was also determined in order to ascertain the best formulation to be applied on the hessian cloth for the improvement of its physicomechanical properties.     

Effects of reactive diluents on mechanical and physical properties of a UV curable acrylated urethane prepolymer

In this study, the dependence of the mechanical properties of a UV curable acrylated urethane on reactive diluent types and their amounts was investigated. The acrylated urethane prepolymer was synthesized from isophorone diisocyanate (IPDI), an aliphatic diisocyanate, and polypropylene glycol monomethacrylate (PPGMMA) by stepwise addition reaction. UV sensitive mixtures containing N-vinylpyrrolidinone (NVP), thiodiethylene glycol diacrylate (TDGDA) and isobornyl acrylate (IBoA) as reactive diluents were irradiated by UV light. An increase in reactive diluent content, either TDGDA or IBoA, caused an increase in tensile strength and a decrease in elongation values. In contrast, above a certain concentration a decrease in tensil strength was observed when NVP was used as reactive diluent. The water absorption capacities of the UV curable acrylated urethane films were observed to depend on type and amount of reactive diluent that was used. Thermooxidative properties of the films were also improved by incorporation of reactive diluents into formulations.     

Characterization of Radiation-Induced Thin Films of Urethane Oligomer

Forty different formulations were developed with urethane diacrylate (M1200) oligomers (containing an aliphatic backbone chain) in the presence of eight different functional monomer diluents additives and five co monomers (co additives). Thin films, prepared with these formulations under ultraviolet (UV) and electron beam (EB) radiations, were characterized. The theological properties were correlated with glass transition temperature (T _g) of the co monomer diluents. Results obtained with M1200 under UV and EB radiations are discussed and compared with those of aromatic urethane (M1100) films, previously reported.     

Modification and characterization of photo-cured sodium alginate film with ethylene glycol: effect of additives

Thin films of sodium alginate (SA) were prepared by casting from methanol solutions. Tensile strength and elongation at break (Eb%) of the films were found to be 20.4 MPa and 11.6 %, respectively. A series of SA solutions (formulations) were prepared by blending varying percentages (2–8 % by wt) of ethylene glycol (EG) and then films were prepared and cured under UV radiation at different intensities (5–35 UV passes). Monomer concentration, soaking time, and radiation dose were optimized in terms of polymer loading and mechanical properties of the cured films. For the improvement of the properties, several acrylic monomers of different functionalities as additives (2 %) like 2-ethylhexyl acrylate, 1,4-butanediol diacrylate, and trimethylolpropane triacrylate were incorporated with EG with the aid of UV radiation. Further analyses of the prepared films were characterized by FTIR and thermogravimetric analysis. Water uptake behavior was determined for the raw and cured SA films.     

Synthesis of bis[(4-hydroxyethoxy)phenyl]sulfone containing urethane acrylates and their applications

UV-curing processes are used in industrial applications because of their advantages such as high speed applications and solvent-free formulations at ambient temperature. UV-curable sulfone containing polyurethane acrylates were synthesized from bis[(4-hydroxyethoxy)phenyl]sulfone (BHEPS), polyols, isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA). The polyurethane acrylates characterized with ¹H NMR and FT-IR spectroscopies. The UV-cured coatings and films were formulated with polyurethane acrylates, reactive diluents such as dipropyleneglycol diacrylate (DPGDA), 1,6-hexanediol diacrylate (HDDA) and photoinitiator. The water wettability of the UV-cured films was investigated by measuring contact angle. Sulfone containing polyurethane acrylates increase mechanical properties such as pendulum hardness, pencil hardness, tensile strength, and e-modulus values. These mechanical properties and chemical-solvent resistance may have been strongly dependant on the sulfone content and crosslinking density.     

Dual-curable PVB based adhesive formulations for cord/rubber composites: The influence of reactive diluents

In this study, the effects of reactive diluent type on the adhesion strength of cord/rubber surfaces were investigated. For this purpose, a urethane acrylate oligomer was synthesized by the reaction of 2,4-toluene diisocyanate (TDI), 2-hydroxyethyl methacrylate (HEMA) and polyvinyl butyral (PVB) in the presence of di-n-butyltin dilaurate (T12) as catalyst. The structure of the oligomer was characterized by nuclear magnetic resonance (NMR) spectroscopy. Then the oligomer was included in adhesive formulations together with trimethylolpropane trimethacrylate (TMPTMA) and tricyclodecane dimethanol diacrylate (TCDDA) as reactive diluents and thermal and photo initiator respectively. Polyester/polyamide cord fabrics were dipped into the adhesive solution and cured by UV-light. Then coated fabrics were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Contact angle measurement was employed to investigate the wettability properties of the coated fabrics. Thermal curing between the coated fabric and rubber was performed under heat and pressure. The adhesion strength between the cord/rubber surfaces was determined by T-peel test. The highest adhesion strength of 100.4 N/cm with the lowest contact angle value of 70.2° were obtained in the sample containing TCDDA as reactive diluent, due to a higher functionality resulting in a greater crosslinking density.     

Ultraviolet‐curing behavior and mechanical properties of a polyester acrylate resin

Ultraviolet (UV) curing technology has been widely used in many applications because it has several distinct advantages compared to solvent‐based processes or thermal‐curing technology. The effects of photoinitiator types and their contents as well as reactive diluent types and their contents on the UV‐curing behavior and mechanical properties of a UV‐curable polyester acrylate resin were investigated in this study. Three photoinitiators, Irgacure 184, Darocur 1173, and benzophenone, were used in this study. Hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylol propane triacrylate were used as reactive diluents to modify the properties of the acrylate resin. The change of chemical structure during UV curing was monitored by FTIR. A universal testing machine was used to measure the tensile properties of various UV‐cured acrylate films of different compositions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3921–3928, 2004     

Using mixture experimental design to study the effect of multifunctional acrylate monomers on UV cured epoxy acrylate resins

An epoxy acrylate resin was synthesized and the resin was used along with different multifunctional acrylate monomers, i.e. trimethylol propane triacrylate (TMPTA), tripropylene glycol diacrylate (TPGDA), 1,6-hexanedioldiacrylate (HDDA). The effect of the chemical structure of the monomers on some of the physical–mechanical properties of the resins and their cured films, such as viscosity, T_g, hardness and scratch resistance was studied. To minimize the number of experiments, mixture method was used as an appropriate tool for experimental design.