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 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.     

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 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     

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 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 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 molecular weight of epoxidized‐natural rubber on viscosity and tack of pressure‐sensitive adhesives

The effect of molecular weight of rubber on viscosity and loop tack of rubber‐adhesives were studied using two grades of epoxidized‐natural rubber, i.e., ENR 25 and ENR 50. Coumarone–indene resin, gum rosin, and petro resin were used as tackifiers. Toluene was used as the solvent throughout the experiment. The adhesive was coated on polyethylene terephthalate (PET) substrate using a SHEEN hand coater. Viscosity was determined by a HAAKE Rotary Viscometer, whereas loop tack was measured by a Llyod Adhesion Tester operating at 10 cm/min. Results show that viscosity increases gradually upto a critical molecular weight of 6.8 × 10⁴ and 3.9 × 10⁴ for ENR 25 and ENR 50, respectively, before a rapid increase in viscosity is observed. Loop tack indicates maximum value at the respective critical molecular weights for the three tackifiers investigated suggesting the culmination of wettability. For both rubbers, loop tack increases with coating thickness due to the concentration effect of adhesive. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Adhesion property of crosslinked epoxidized (natural rubber)/(acrylonitrile‐butadiene) rubber blend adhesives in the presence of petro resin tackifier

Loop tack, peel strength, shear strength, and morphology of (benzoyl peroxide)‐cured epoxidized natural rubber (ENR 25)/(acrylonitrile‐butadiene) rubber (NBR) blend adhesive were investigated by using petro resin as the tackifying resin. Benzoyl peroxide loading varied from 1 to 5 parts by weight per hundred parts of resin (phr), whereas the petro resin loading was fixed at 40 phr. A SHEEN hand coater was used to coat the adhesive on the polyethylene terephthalate substrate at 30 μm and 120 μm coating thicknesses. (ENR 25)/NBR adhesive was crosslinked at 80°C for 30 min prior to the determination of adhesion strength by a Lloyd adhesion tester operating at 10–60 cm/min. Results show that maximum loop tack and peel strength occur at 2 phr of benzoyl peroxide loading, whereby optimum cohesive and adhesive strength are obtained. However, shear strength increases with increasing benzoyl peroxide concentration, an observation that is associated with the steady increase in the cohesive strength. Scanning electron microscopy micrograph shows that little adhesive remained on the substrate at 0 phr compared with 2 phr of benzoyl peroxide loading, indicating that crosslinking increases the peel strength of the adhesive. In all cases, the adhesion properties increase with coating thickness and testing rate . J.VINYL ADDIT. TECHNOL., 24:93–98, 2018. © 2015 Society of Plastics Engineers     

Effect of N‐isopropyl‐N′‐phenyl‐p‐phenylenediamine antioxidant on the adhesion properties of (zinc oxide)‐filled (epoxidized natural rubber 25)‐based pressure‐sensitive adhesives

The effect of antioxidant, namely, N‐isopropyl‐N′‐phenyl‐p‐phenylenediamine (IPPD), on the adhesion properties of epoxidized natural rubber (ENR 25)‐based pressure‐sensitive adhesive was investigated. The concentration of the IPPD was varied from 0 to 5 parts by weight per hundred parts of rubber (phr). Coumarone‐indene resin, zinc oxide, toluene, and polyethylene terephthalate were used as the tackifier, filler, solvent, and substrate, respectively. A Lloyd Adhesion Tester operating at different testing rates (10–60 cm/min) was used to determine the loop tack, peel strength, and shear strength at 60‐µm and 120‐µm coating thicknesses. Results indicate that adhesion properties increase with IPPD up to 2 phr of content, after which it decreases with further addition of the antioxidant. This observation is attributed to the culmination of wettability and compatibility at the optimum IPPD concentration. The 60‐µm coated sample consistently shows higher adhesion strength than that of 120‐µm coated sample. Loop tack and peel strength increase with testing rate up to 30 cm/min. However, shear strength increases with increasing testing rate in the testing rate investigated in this study. J. VINYL ADDIT. TECHNOL., 21:111–115, 2015. © 2014 Society of Plastics Engineers     

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.     

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     

The Effect of Silica on the Peel Adhesion of Epoxidized Natural Rubber-Based Adhesive Containing Coumarone-Indene Resin

The peel strength of silica filled on two grades of epoxidized natural rubber (ENR), i.e., ENR 25 and ENR 50 adhesive were investigated using coumarone-indene as the tackifying resin. Toluene was used as the solvent throughout the study. Result shows that peel strength increases with increase in silica loading due to the concentration effect of the filler. Peel strength, however, shows maximum value at 40 phr silica for both ENR 25 and ENR 50 an observation that is attributed to the maximum wettability and compatibility of adhesive on the substrate.     

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 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.     

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 molecular weight of epoxidized natural rubber on shear strength of adhesives

The dependence of shear strength of epoxidized natural rubber (ENR)‐based adhesives on molecular weight of the rubber is studied using coumarone–indene resin, gum rosin, and petro resin as tackifiers. The adhesive was coated on polyethylene terephthalate (PET) film substrate using a SHEEN hand coater at various coating thickness. The shear strength of adhesives was determined by a Texture Analyzer. Results show a maximum at 6.63 × 10⁴ and 4.14 × 10⁴ for ENR 25 and ENR 50, respectively, after which the shear strength decreases with further increases in molecular weight for all the coating thickness. This observation is attributed to varying degree of cohesiveness which culminates at the respective optimum molecular weight of ENR. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

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 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.     

Shear Property of Kaolin-filled Standard Malaysian Rubber (SMR L) Pressure-sensitive Adhesive

The effect of kaolin loading on the viscosity and shear strength of natural-rubber-based pressure-sensitive adhesive was studied using coumarone-indene resin, toluene, and polyethylene terephthalate as tackifier, solvent, and substrate, respectively. Kaolin loading ranged from 10 to 60 parts per hundred parts of rubber (phr) whereas the tackifier content was fixed at 40 phr. The viscosity and shear strength—from lap shear test—were determined by a Brookfield viscometer and Lloyd adhesion tester, respectively. Results show that viscosity increases with increasing kaolin loading. However, shear strength increases up to 20 phr kaolin loading, after which it decreases with further filler loading. This observation is attributed to the culmination of cohesive strength at the optimum loading of kaolin filler. For a fixed kaolin loading, the shear strength increases with coating thickness and testing rate.