Adhesion Property of Benzoyl-Peroxide-Cured Epoxidized Natural Rubber/Acrylonitrile-Butadiene Rubber Blend Adhesives to Polyethylene Terephthalate Film

The loop tack, peel strength and shear strength of cross-linked epoxidized natural rubber (ENR-50)/acrylonitrile-butadiene rubber (NBR) blend adhesives were studied in the presence of coumarone-indene resin. Benzoyl peroxide was used as the cross-linking agent with dosage ranging from 1 to 5 parts per hundred rubber by weight (phr). Toluene was used as the solvent throughout the investigation. A SHEEN hand coater was used to coat the adhesive on a polyethylene terephthalate substrate at 60 and 120 μm coating thickness. The adhesive was cured at 80°C for 30 min prior to testing on a Lloyd adhesion tester operating at various testing rates from 10 to 60 cm min^?1. Results show that loop tack and peel strength of the ENR-50/NBR adhesives pass through a maximum value at 4 phr of benzoyl peroxide dosage. This observation is attributed to the increase in cohesive strength which culminates at 4 phr benzoyl peroxide loading. However, shear strength increases steadily with dosage of benzoyl peroxide due to the continuous increase in the cohesive strength as crosslinking of the rubber blend proceeds. In all cases, the adhesion properties increase with increasing coating thickness and testing rates.     

Adhesion behavior of natural rubber‐based adhesives crosslinked by benzoyl peroxide

The loop tack, peel, and shear strength of crosslinked natural rubber adhesive were studied using coumarone‐indene and toluene as the tackifying resin and solvent, respectively. The concentration of benzoyl peroxide‐the crosslinking agent—was varied from 1 to 4 parts per hundred parts of rubber (phr). A SHEEN hand coater was used to coat the adhesive on the polyethylene terephthalate substrate at various coating thickness. Loop tack, peel, and shear strength were measured by a Llyod adhesion tester operating at 30 cm min^?1. Result shows that loop tack and peel strength of the adhesive increases up to 2 phr of benzoyl peroxide concentration after which it decreases with further benzoyl peroxide content. This observation is attributed to the optimum crosslinking of natural rubber where optimum cohesive and adhesive strength occurs at 2 phr peroxide loading. However, for the shear strength, it increases with increasing benzoyl peroxide concentration where higher rate of increase is observed after 2 phr of peroxide content, an observation which is associated to the steady increase in cohesive strength of crosslinked rubber. In all cases, the adhesion properties of adhesives increase with increase in coating thickness. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Dependence of Adhesion Properties of Cross-linked Epoxidized Natural Rubber (ENR 25)-Based Pressure-Sensitive Adhesives on Benzoyl Peroxide Loading in the Presence of Gum Rosin and Petroresin Tackifiers

The effect of benzoyl peroxide loading on the adhesion properties of cross-linked epoxidized natural rubber (ENR 25)-based adhesives was studied using gum rosin and petroresin as tackifiers. Toluene and polyethylene terephthalate (PET) were used as solvent and coating substrate, respectively. The adhesion properties were determined by a Lloyd adhesion tester operating at 30 cm min^?1. Results indicate that the loop tack and peel strength of gum rosin and petroresin pass through a maximum value at 2 parts per hundred parts of rubber (phr) and 3 phr benzoyl peroxide concentration, respectively, an observation which is attributed to the optimum cross-linking of ENR 25 where optimum, cohesive and adhesive strength is obtained. The shear strength, however, increases steadily with increasing benzoyl peroxide loading due to the steady increase in the cohesive strength. At the optimum benzoyl peroxide concentration, the petroresin-based adhesive consistently exhibits higher adhesion properties compared to that of gum rosin-based adhesives. The adhesion properties of both adhesive systems increase with increasing coating thickness.     

Effect of zinc oxide on the viscosity and adhesion property of epoxidized natural rubber/acrylonitrile‐butadiene rubber‐based pressure‐sensitive adhesives

Viscosity, loop tack, peel strength, and shear strength of epoxidized natural rubber (ENR 50)/acrylonitrile‐butadiene rubber (NBR)–based pressure‐sensitive adhesive were studied in the presence of zinc oxide. The zinc oxide concentration was varied from 10 to 50 parts by weight per hundred parts of rubber (phr). Coumarone–indene resin with loading of 40 phr was chosen as the tackifier resin. Toluene and polyethylene terephthalate were used as the solvent and coating substrate, respectively, throughout the experiment. The adhesive was coated on the substrate by using a SHEEN hand coater. Viscosity of the adhesive was determined by a Brookfield Viscometer, whereas the loop tack, peel strength, and shear strength were measured by a Lloyd Adhesion Tester operating at 30 cm/min. Results indicate that viscosity increases with zinc oxide concentration owing to the concentration effect. Loop tack and peel strength pass through a maximum value at 20 phr of zinc oxide concentration. This observation is associated with the effect of varying degrees of wettability of the adhesive on the substrate. Shear strength, however, increases steadily with increasing zinc oxide loading owing to the steady increase in cohesive strength. In all cases, the adhesion properties of adhesives increase with increasing coating thicknesses. J. VINYL ADDIT. TECHNOL., 22:410–414, 2016. © 2015 Society of Plastics Engineers     

Peel and shear strength of pressure‐sensitive adhesives prepared from epoxidized natural rubber

Peel and shear strength of two grades of epoxidized natural rubber (ENR 25 and ENR 50)‐based pressure‐sensitive adhesive was studied. Coumarone‐indene resin was used as the tackifier, whereas toluene was chosen as the solvent throughout the experiment. The tackifier loading was varied from 0 to 80 parts per hundred parts of rubber (phr). A SHEEN hand coater was used to coat the adhesive on substrate to give a coating thickness of 30, 60, 90, and 120 μm. Peel strength and shear strength of the adhesive were determined by using a Lloyd adhesion tester and Texture analyzer, respectively. Results show that maximum peel strength occurs at 40 phr of coumarone‐indene resin for both ENRs studied an observation, which is attributed to the maximum wettability of the substrate. However, the shear strength shows a gradual decrease with increasing tackifier loading because of the decrease in cohesive strength of adhesive. ENR 25 consistently indicates higher peel strength and shear strength than ENR 50. Generally, peel and shear strength increases with coating thickness. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.     

Effect of Magnesium Oxide and the Testing Rate on the Viscosity and Adhesion Properties of Epoxidized Natural Rubber/Acrylonitrile–Butadiene Rubber Blend Based Adhesives

The effect of magnesium oxide loading on the adhesion properties of epoxidized natural rubber (ENR 50)/acrylonitrile–butadiene rubber (NBR)-based pressure-sensitive adhesives was systematically investigated using 40 parts per hundred parts of rubber (phr) of coumarone–indene resin as the tackifier. The concentration range of magnesium oxide was from 10–50 phr. Toluene and polyethylene terephthalate (PET) films were selected as the solvent and the substrate, respectively, throughout the experiment. A Sheen hand coater was used to coat the adhesive onto the PET substrate at various coating thicknesses. The viscosity of the adhesive was measured using a Brookfield viscometer, whereas the loop tack, peel strength, and shear strength were determined using an adhesion tester operating at 10–60 cm/min. The results indicate that the viscosity increases with magnesium oxide loading, an observation which is attributed to the concentration effect of the filler. However, loop tack, peel strength, and shear strength increase with magnesium oxide loading up to 30 phr before decreasing upon further addition of the filler. This observation is ascribed to the effect of a varying degree of wettability of the adhesive, which culminates at 30 phr of magnesium oxide loading. At a fixed loading of magnesium oxide, all the adhesion properties of adhesives increase upon increasing the coating thickness and rate of testing.     

Effect of zinc oxide and testing rate on the adhesion property of styrene‐butadiene rubber/standard Malaysian rubber blend adhesives

The effect of zinc oxide and testing rate on tack, peel strength, and shear strength of styrene‐butadiene rubber (SBR)/standard Malaysian rubber (SMR L) blend adhesive was investigated using coumarone‐indene resin and toluene as the tackifying resin and solvent, respectively. Zinc oxide concentration was varied from 0–50 parts per hundred parts of rubber (phr). A Lloyd Adhesion Tester operating from 10–60 cm/min was used to determine the adhesion property. Results show that tack and peel strength increases with zinc oxide concentration up to 20 phr of the filler loading. This observation is attributed to the varying degree of wettability, which culminates at 20 phr of zinc oxide content. For the shear strength, it increases steadily with zinc oxide loading, an observation that is associated to the steady increase in cohesive strength due to the interaction between the adhesive and the filler. The adhesion property increases with testing rate and coating thickness. J. VINYL ADDIT. TECHNOL., 22:3–7, 2016. © 2014 Society of Plastics Engineers     

Adhesion properties of benzoyl peroxide crosslinked epoxidized natural rubber (ENR 25)‐based pressure‐sensitive adhesives

Adhesion properties of crosslinked (epoxidized natural rubber)‐based adhesives were studied by using coumarone‐indene, benzoyl peroxide, and toluene as tackifying resin, crosslinking agent, and solvent, respectively. The adhesion properties were measured by a Lloyd Adhesion Tester operating at 30 cm min^?1. Results show that loop tackiness and peel strength pass through a maximum value at 1 phr (parts by weight per hundred parts of resin) of benzoyl peroxide concentration, an observation that is attributed to the optimum crosslinking of epoxidized natural rubber whereby optimum cohesive and adhesive strength are obtained. However, shear strength increases with increasing benzoyl peroxide concentration wherein the higher rate of increase is observed between 0 and 1 phr of benzoyl peroxide content. This observation is associated with the steady increase in cohesive strength as crosslinking is increased. In all cases, the adhesion properties of adhesives increased with increasing coating thickness. J. VINYL ADDIT. TECHNOL., 22:8–12, 2016. © 2014 Society of Plastics Engineers     

Dependence of adhesion property of acrylonitrile‐butadiene rubber‐based adhesive on zinc oxide concentration

Viscosity and adhesion properties of acrylonitrile‐butadiene rubber (NBR)‐based pressure‐sensitive adhesive were investigated by using zinc oxide as the filler. The zinc oxide loading was varied from 10 to 50 parts by weight per hundred parts of rubber (phr). Coumarone–indene resin, toluene, and polyethylene terephthalate were used as the tackifying resin, solvent, and coating substrate, respectively. Viscosity of the adhesive was measured by a Brookfield viscometer, whereas the loop tack, peel strength, and shear strength were determined by a Lloyd adhesion tester operating at 10 to 60 cm/min. Results show that viscosity increases with zinc oxide loading because of the concentration effect. Loop tack and peel strength pass through a maximum value at 20 phr of zinc oxide concentration, whereas the optimum zinc oxide loading for shear strength is 30 phr. This observation is attributed to the effect of varying degrees of wettability and compatibility of the adhesive on the substrate. In all cases, the adhesion properties of adhesives increase with coating thickness and testing rates. J. VINYL ADDIT. TECHNOL., 23:241–246, 2017. © 2015 Society of Plastics Engineers     

Effect of zinc oxide on the viscosity,tack, and peel strength of ENR 25‐based pressure‐sensitive adhesives

Viscosity, loop tack, and peel strength of epoxidized natural rubber (ENR 25 grade)‐based pressure‐sensitive adhesive was studied in the presence of zinc oxide. The zinc oxide concentration was varied from 10–50 parts per hundred parts of rubber (phr). Coumarone–indene resin with loading from 20 to 100 phr was chosen as the tackifier resin. Toluene was used as the solvent throughout the experiment. The adhesive was coated on the substrate using a SHEEN hand coater to give a coating thickness of 60 μm. Viscosity of the adhesive was determined by a HAAKE Rotary Viscometer whereas the loop tack and peel strength were measured by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity and loop tack of adhesive increases with increasing zinc oxide concentration. For the peel strength, it increases with zinc oxide concentration up to 30–40 phr and drops after the maximum value. This observation is associated with the effect of varying degree of wettability of the adhesive on the substrate. However, for a fixed zinc oxide concentration, loop tack and peel strength exhibit maximum value at 80 phr resin loading after which both properties decrease with further addition of resin, an observation which is attributed to phase inversion. From this study, the optimum adhesion property is achieved by using 40 phr zinc oxide and 80 phr coumarone–indene resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of Barium Chloride Filler on the Adhesion Properties of Epoxidized Natural Rubber (ENR 25)-Based Adhesives

The adhesion properties of epoxidized natural rubber (ENR 25)-based adhesive were studied using barium chloride, coumarone-indene resin and toluene as the filler, tackifier and solvent respectively. Viscosity was determined by a Brookfield Viscometer whereas tack, shear and peel strength was measured by a Llyod Adhesion Tester. Results show that viscosity of adhesive increases gradually with increasing barium chloride loading. Loop tack, shear and peel strength indicates a maximum value at 10 parts per hundred parts of rubber (phr) of barium chloride, an observation that is attributed to the maximum wettability and compatibility of adhesive on the substrate.     

Effect of Blend Ratio and Testing Rate on the Adhesion Properties of Epoxidized Natural Rubber (ENR 25)/Styrene–Butadiene Rubber (SBR) Blend Adhesive

The effect of rubber blend ratio and testing rate on the adhesion properties of epoxidized natural rubber (ENR 25)/styrene–butadiene rubber (SBR) blend adhesive were studied using 40 parts per hundred parts of rubber (phr) of coumarone-indene resin as the tackifying resin. Toluene and poly(ethylene terephthalate) (PET) film were used as the solvent and substrate, respectively. A SHEEN hand coater was used to coat the adhesive on the PET substrate at 30, 60, 90, and 120 µm coating thickness. Viscosity was determined by a Brookfield viscometer whereas loop tack, peel strength, and shear strength were measured by a Llyod Adhesion Tester at various testing rates from 10 to 60 cm/min. Results show that viscosity increases gradually with % ENR 25. However, loop tack, peel strength, and shear strength of adhesives indicate a maximum value at 40% ENR 25, after which the adhesion properties decreases with further increase in % ENR 25. This observation is attributed to the varying degree of wettability which culminates at an optimum value of 40% ENR 25 blend ratio. In all cases, the adhesion properties increase with increasing coating thickness and rate of testing.     

Effect of silica on viscosity,tack, and shear strength of epoxidized natural rubber‐based pressure‐sensitive adhesives in the presence of coumarone‐indene resin

The viscosity, loop tack, and shear strength of silica‐filled epoxidized natural rubber (ENR 25 and ENR 50 grade) adhesive were investigated using coumarone‐indene as the tackifying resin. Silica loading was varied from 10–50 parts per hundred parts of rubber (phr), whereas the coumarone‐indene concentration was fixed at 40 phr. Toluene was used as the solvent throughout the study. Polyethylene terephthalate substrate was coated at various adhesive coating thicknesses, i.e., 30, 60, 90, and 120 μm using a SHEEN Hand Coater. Viscosity of the adhesive was determined by a HAAKE Rotary Viscometer whereas loop tack and shear strength were measured by a Llyod Adhesion Tester operating at 30 cm/min. Result shows that viscosity of the adhesive increases gradually with increase of silica loading due to the concentration effect of the filler. Both loop tack and shear strength show maximum value at 40 phr silica for ENR 25. However, the respective values for ENR 50 are 20 and 40 phr of filler. This observation is attributed to the maximum wettability and compatibility of adhesive on the substrate at the respective silica loadings. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Adhesion properties of (epoxidized natural rubber)/(ethylene‐propylene‐diene rubber) blend adhesive: Effect of blend ratio and testing rate

The adhesion properties of epoxidized natural rubber (ENR 25)/(ethylene‐propylene‐diene rubber) blend adhesive were investigated by using various blend ratios of the two rubbers and rate of testing. Coumarone‐indene resin was used as the tackifier. Results show that the loop tack and peel strength of adhesives increase steadily up to 60% ENR 25 before decreasing with further increase in % ENR 25. This observation is attributed to an increase in wettability and compatibility up to the optimum value of the ENR 25 blend ratio. However, shear strength increases continuously with increasing percentage of ENR 25, an observation that is ascribed to the increasing cohesive strength of the blend adhesive. In all cases, the adhesion properties increase with increasing coating thickness and testing rates. J. VINYL ADDIT. TECHNOL., 22:134–139, 2016. © 2014 Society of Plastics Engineers     

Effect of Testing Rate on Adhesion Properties of Benzoyl-Peroxide-Cured ENR 25/NBR Blend Adhesive Using Gum Rosin and Coumarone-Indene Resin as Tackifiers

Dependence of adhesion properties of benzoyl-peroxide-cured epoxidized natural rubber (ENR 25)/acrylonitrile-butadiene rubber (NBR) blend adhesive on testing rate was systematically studied. Coumarone-indene resin and gum rosin were used as tackifiers. Toluene was used as solvent throughout the study. The SHEEN hand coater was used to coat the adhesive on polyethylene terephthalate at 30 and 120 µm coating thickness. The adhesion properties were measured by a Lloyd adhesion tester operating at different rates of testing. Results showed that the loop tack, peel strength, and shear strength increased with increasing testing rate, an observation that was attributed to the viscoelastic nature of adhesive. In all cases, the adhesion properties of the adhesives also increased with increasing coating thickness.     

Tack and Shear Strength of Adhesives Prepared from Styrene-Butadiene Rubber (SBR) Using Gum Rosin and Petro Resin as Tackifiers

Tack and shear strength of styrene-butadiene rubber (SBR)-based pressure-sensitive adhesive were studied using gum rosin and petro resin as the tackifiers. The concentration of the tackifying resin was varied from 0 to 100 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment. The rolling ball technique was used to measure the tack of the adhesive, whereas, shear strength was determined by a TA-HDi Texture Analyser. Results show that the tack of the adhesive increases with increasing tackifier loadings for both tackifier systems. However, shear strength indicates the reverse behavior with increasing resin content, an observation which is attributed to the decrease in cohesive strength as the tackifier concentration is increased. Both tack and shear strength of the adhesives increases with molecular weight of SBR. Adhesive containing petro resin consistently exhibits higher values than the gum rosin system due to better wettability and compatibility in the former system.     

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     

Viscosity,shear strength,and peel strength on poly(ethylene terephthalate) of (natural rubber)‐based adhesives containing hybrid tackifiers

The viscosity, shear strength, and peel strength of [natural rubber (Standard Malaysian Rubber (SMR) L grade)]‐based pressure‐sensitive adhesives were studied by using hybrid tackifiers, i.e., mixtures of coumarone–indene resin and petro resin. Toluene and poly(ethylene terephthalate) were used as the solvent and substrate, respectively. Viscosity of the adhesives was determined with a HAAKE rotary viscometer, whereas shear and peel strength were measured by a Lloyd adhesion tester. Results showed that the viscosity and shear strength decreased with increasing petro resin concentration, an observation which is attributed to the plasticizing effect of the resin. Peel strength, however, showed a maximum value at 60 phr (parts by weight per hundred parts of resin) petro resin concentration, thus indicating maximum wettability at this petro resin content. Peel strength increased with coating thickness for all the peel tests studied. In all cases, a 90° peel test consistently exhibited the highest peel value. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers     

Effect of molecular weight and testing rate on peel and shear strength of epoxidized natural rubber (ENR 50)‐based adhesives

The dependence of peel strength and shear strength of epoxidized natural rubber (ENR‐50)‐based pressure sensitive adhesive on molecular weight and rate of testing was investigated using coumarone‐indene as the tackifying resin. Toluene and polyethylene terephthalate were used as the solvent and substrate respectively, throughout the study. A SHEEN hand coater was used to coat the adhesive on the substrate at a coating thickness of 120 μm. All the adhesion properties were determined by a Llyod Adhesion Tester operating at different rates of testing. Result shows that peel strength and shear strength increases up to an optimum molecular weight of 4.2 × 10⁴ of ENR 50. For peel strength, the observation is attributed to the combined effects of wettability and mechanical strength of rubber at the optimum molecular weight, whereas for the shear strength, it is ascribed to the optimum cohesive and adhesive strength which enhances the shear resistance of the adhesive. Peel strength and shear strength also increases with increase in rate of testing, an observation which is associated to the viscoeslastic response of the adhesive. DSC and FTIR study confirms the miscibility of tackifier and the ENR 50. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of Coumarone-Indene Resin on Adhesion Property of SMR 20-Based Pressure-Sensitive Adhesives

The viscosity, tack, and peel strength of a natural rubber (SMR 20)–based pressure-sensitive adhesive (PSA) was studied using coumarone-indene resin as the tackifier. The resin loading was varied from 0–80 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment. The viscosity of PSA was measured using a Haake Rotary Viscometer whereas loop tack and peel strength were determined using a Lloyd Adhesion Tester. PSA was coated onto the substrates using a SHEEN hand coater to give a coating thickness of 60 μm and 120 μm. Results show that the viscosity and tack of the adhesive increases with resin content due to the concentration effect of tackifier resin. However, for the peel strength, it increases up to 40 phr of resin for both coating thickness, an observation that is attributed to the wettability of substrates.