Top PDF Soybean-Based Adhesive Resins and Composite Products Utilizing Such Adhesives (2003)

Soybean Based Adhesive Resins and Composite Products Utilizing Such Adhesives (2003)

Soybean Based Adhesive Resins and Composite Products Utilizing Such Adhesives (2003)

The present invention relates to a soybean-based adhesive resin including a soybean flour and a cross-linking agent. The cross-linking agent is reacted with the functional groups in the soybean flour to form an adhesive resin. The present invention also relates to a method of making a soybeanbased adhesive resin. This method involves providing an aqueous solution of soybean flour and adding a cross-linking agent to the solution under conditions effective to cross-link the soybean flour so that an adhesive resin is formed. Also disclosed is a composite product which includes particulate plant material and the soybean-based adhesive resin. The adhesive is prepared by reacting the cross-linking agent with the functional groups in the soybean flour. The present invention also relates to a method of making a composite product by providing particulate plant material and applying the soybean-based adhesive resin to the particulate plant material.
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Soybean Based Adhesive Resins and Composite Products Utilizing Such Adhesives (2001)

Soybean-Based Adhesive Resins and Composite Products Utilizing Such Adhesives (2001)

The present invention relates to a soybean-based adhesive resin including a soybean flour and a cross-linking agent. The cross-linking agent is reacted with the functional groups in the soybean flour to form an adhesive resin. The present invention also relates to a method of making a soybeanbased adhesive resin. This method involves providing an aqueous solution of soybean flour and adding a cross-linking agent to the solution under conditions effective to cross-link the soybean flour so that an adhesive resin is formed. Also disclosed is a composite product which includes particulate plant material and the soybean-based adhesive resin. The adhesive is prepared by reacting the cross-linking agent with the functional groups in the soybean flour. The present invention also relates to a method of making a composite product by providing particulate plant material and applying the soybean-based adhesive resin to the particulate plant material.
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Synthetic resins and their properties in respect of development of jute based composite boards

Synthetic resins and their properties in respect of development of jute based composite boards

thermoset polymer for adhesives and composites. Epoxy resin is two times stronger than concrete, seamless and waterproof. Polyamide resin is another example of synthetic resins. Polyamide resins are products of polymerization of an amino acid or the condensation of a diamine with a dicarboxylic acid. They are used for fibers, bristles, bearings, gears, molded objects, coatings, and adhesives. The term nylon formerly referred specifically to synthetic polyamides as a class. Because of many applications in mechanical engineering, nylons are considered engineering plastics. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, lacquers, paints, rubber and pharmaceutical uses. The applications of synthetic resins are seen in some important industries like paint industry, adhesive industry, the printing ink industry, the textile industry, the leather industry, the floor polish, paper, agricultural industry etc. As it can be seen that there is an enormous scope of application of resins hence it is one of the major field to venture.
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Vickers Hardness of Composite Resins Cured with LED and QTH Units

Vickers Hardness of Composite Resins Cured with LED and QTH Units

Differences between light-curing units and exposure times can be considered as reasons for such discrepancy. In the present study, the hardness of Filtek Z250 was higher when it was cured with QTH unit compared to when it was cured with LED unit; this is consistent with the results of Sadeghiyani et al. and Polydorou et al., who used two translucent composite resins exposed to QTH and LED units [1,18]. Sadeghiyani used Astralis 7 as QTH. In both studies, the results mentioned for better results of QTH was noticeable heat produced with light unit. Composite resin hardness after polymerization is affected by some factors, including composition of composite resin, type of light initiator, light unit, and the amount of light energy with a suitable wavelength [3].
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Experimental Comparison of Hygroscopic Expansion in Three  Different Composite Resins

Experimental Comparison of Hygroscopic Expansion in Three Different Composite Resins

ples hardened in zero distance was significantly higher than the samples hardened in 5 mm dis- tance. Besides, the findings in this study showed that the ratio of the surface microleakage to the depth in the LED machine is higher than halogen [16]. Another important point in the mentioned studies is that in the majority of them single va- riable statistical tests such as analysis of variance was used to compare different properties of the composite. Based on the above mentioned mat- ters, the objective of this study was to use an ap- propriate statistical method to analyze the longi- tudinal data in order to evaluate the change in the hygroscopic expansion of three Z250, P90 and Kalore composites in a three-month period in two saliva and distilled water environments.
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Analysis of Adhesive Bonded Fiber-Reinforced Composite Joints

Analysis of Adhesive Bonded Fiber-Reinforced Composite Joints

Frostig et al. [7] developed a closed-form higher-order theory (CFHO) for the analysis of adhesive bonded joints. This approach satisfies the boundary/continuity conditions in the adhesive layer at the edge of the overlap. This differs from the Goland- Reissner type solutions that only satisfy these conditions globally. This will be explained in greater detail in chapter 3. It also assumes that transverse normal stresses are not uniform through the thickness. These factors allow for the adhesive layer to fulfill point, as well as global equilibrium. The governing equations for this theory have been derived assuming that the adherends are linearly elastic composite laminates and the adhesive layer is homogeneous, isotropic and linear-elastic. Good agreement was found with a comparable finite element solution and a Goland and Reissner solution for both a square edge and a fillet at the edge of the overlap in the adhesive. However, because the non- linearity in the adhesive was not taken in to account, the results will predict a higher stress than actually exists.
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In vitro evaluation of the shear bond strength between fiber posts and methacrylate or silorane based composite resins

In vitro evaluation of the shear bond strength between fiber posts and methacrylate or silorane based composite resins

restorative. Two 2.0 mm thick specimens were obtained from each fiber post unit and submitted to a push-out test in a universal testing machine with a 5 mm/min cross- head speed and 5 Kilo-newton load cell. Mean and standard deviation values for bond strength (MPa) were: G1: 5.54 ± 1.78; G2: 1.69 ± 1.02; G3: 5.31 ± 1.58; G4: 7.39 ± 2.05; G5: 6.07 ± 1.88e G6: 5.50 ± 3.03. The results were analyzed through two-way analysis of variance (ANOVA) and statistical significant differences were determined by Tukey test (p = 0.05). When no adhesive was used, the bond strength was statistically significantly higher for G1 and G3, which were not statistically significantly different between them. Adhesive application showed statistically significantly higher bond strength only for G5. Without the FP pretreatment with adhesive, the bond strength was statistically significantly higher for the methacrylate-based resins and the FP pretreatment with adhesive increased the bond strength only for the silorane-based resin and changed the prevalence of failure mode type to cohesive in all composite resin study groups. The use of silorane-based composite resins to customize posts require the use of adhesive as FP surface pretreatment. The use of adhesive as pretreatment of simulated customized FP, regardless of the CR used, appear to improve the mechanical behavior of the FP-CR unit.
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Relationship between Color and Translucency of Multishaded Dental Composite Resins.

Relationship between Color and Translucency of Multishaded Dental Composite Resins.

Esthet.X Micro Matrix Restorative is an esthetic, visible- light-cured, radiopaque microhybrid composite restorative material designed specifically for use in all cavity classes in both anterior and posterior restorations. The resin matrix of Esthet.X is a urethane modified BIS-GMA resin matrix system. It consists mainly of BIS-GMA adduct, ethoxylated bisphenol-A-dimethacrylate, and TEGDMA. The filler com- ponent of Esthet.X is a blend of a proprietary inorganic bariumalumino fluoroborosilicate (BAFG) glass with nano- sized silicon dioxide particles. The BAFG glass has an average filler particle size of 0.6–0.8 microns with narrow particles size distributions of 0.02–2.5 microns. The silicon dioxide nanofiller is in the range of 10 to 20 nm. The total percentage by volume of inorganic filler is ca. 60 vol.%; the percentage by weight is ca. 77 wt.% [26].
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Translucency and Masking Ability of Various Composite Resins at Different Thicknesses

Translucency and Masking Ability of Various Composite Resins at Different Thicknesses

Five brands of opaque or dentin A2 shade resin compo- sites; Gradia (GC; Tokyo, Japan), Herculite XRV (Kerr; Scafati, Salerno, Italy), Vit-l-escence (Ultradent; South Jordan, USA), Crystalline (Confi-dental; Louisville, USA) and Opallis (FGM, Brazil) were enrolled in this study. Stainless-steel split plates in 0.5, 1, 1.5 mm thicknesses and with a hole of 18 mm in diameter were used as the molds to produce standardized specimens. Each mold was filled with resin composite material and covered with clear celluloid strips on the top and the bottom of the hole. The metal plate was pressed be-
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Microleakage of Self-Adhesive Resin Cements Compared With  Resin Cements Containing Etch & Rinse Adhesives

Microleakage of Self-Adhesive Resin Cements Compared With Resin Cements Containing Etch & Rinse Adhesives

based on self-etch bonding technology have been developed in order to prevent post-cementation sensitivity and to decrease technique sensitivity and operation complexity [10]. Self-adhesive resin cements were introduced in 2002 [5], in which etching, priming and bonding components are in- corporated in the cement preparation. It appears that chemical bond to tooth structure can be achieved to some extent [5]. There is not enough information including long-term clinical data about the composition of these materials. On the other hand controversial data exist concerning leakage comparison of self-adhesive and etch-and-rinse cement systems [1,3,5,8,11]. Al-Saleh and col- leagues in 2010 demonstrated that ScotchBond Multipurpose had the lowest leakage in enamel margin and Rely-X and Breeze showed the lowest leakage in dentinal margins [12]. According to the laboratory results, bondability of self-adhesive ce- ments to dentin and different restorative materials was favorable and comparable to other multi-stage resin cements. On the other hand [5]. The purpose of this study was to compare microleakage of RelyX ARC and Nexus3 resin cements using etch- and-rinse bonding system and Rely X Unicem and Maxcem Elite self-adhesive resin cements 24 hours after application.
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The effects of different opacifiers on the translucency of experimental dental composite resins

The effects of different opacifiers on the translucency of experimental dental composite resins

Objective: The aim of this study was to evaluate the effects of different opacifiers on the translucency of experimental dental composite-resins. Methods: Three metal oxides that are used as opacifiers were tested in this study: titanium oxide (TiO2), aluminium oxide (Al2O3) and zirconium oxide (ZrO2). Experimental composite-resins were fabricated containing 25 wt.% urethane dimethacrylate (UDMA)-based resin matrix and 75% total filler including different concentrations of metal oxides (0, 0.25, 0.5, 0.75 and 1wt.%) blended into silane treated barium-silicate filler. The specimens (15.5 mm diameter and 1 mm thickness) were light-cured and tested in the transmittance mode using a UV/VIS spectrophotometer at wavelengths from 380-700 nm under a standard illuminant D65. The colour differences (∆E* ab) between different concentrations of opacifiers were also measured in transmittance mode based on their Lab values. Results: Statistical analysis by ANOVA and Tukey’s test showed a significant decrease (p<0.05) in light transmittance with the addition of opacifiers to the experimental composite-resins. There was a linear correlation between different concentrations of TiO2 and Al2O3 and total transmittance. Total transmittance was also found to be wavelength dependent. The colour differences for the concentrations of 0-1 wt.% of the opacifiers were above 1 ∆E* unit, with Al2O3 showing the smallest colour shift. Significance: The type and the amount of the opacifiers used in this study had a significant effect on the translucency of the experimental UDMA-based dental composite resins. The most effective opacifier was TiO2, followed by ZrO2 and Al2O3 in decreasing order, respectively.
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In-vitro Shear Bond Strength of a Nano-composite Resin in Comparison with Microfilled and Microhybrid Composite Resins

In-vitro Shear Bond Strength of a Nano-composite Resin in Comparison with Microfilled and Microhybrid Composite Resins

Therefore, based on the results of the study, it can be said that nanocomposites are ideal for both anterior and posterior restorations as they possess excellent esthetic and mechanical properties. This is analogous to the investigations done by previous researchers who demonstrated that microfilled composite resin exhibited the lowest mechanical properties and nanofilled resin composites showed mechanical properties as good as those of universal hybrids and therefore can be used in similar clinical situations [8].
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Kinetic Study of Curing Phenol Formaldehyde/Tannin Formaldehyde Composite Resins

Kinetic Study of Curing Phenol Formaldehyde/Tannin Formaldehyde Composite Resins

The resins that synthesized from TF and PF were thermally cured. According to curing reaction path and the ki- netic data of PF, TF, and TFPF, tannins and tannin-formaldehyde resin can be thermally cured. The participation of tannin-formadehyde with PF to the formation thermosetting network was at high performance. The curing reactions density and acceptable conversion degree of TFPF curing were due to the methylol groups into TF re- sin. The velocity of weight loss during curing TF and TFPF and kinetic parameters of these resins showed that the eucalyptus tannins had high activity to prepare methylolic resins and it is suitable to be partially replacement into PF.
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A comparative evaluation of flexural strength of composite resins on glass fibre reinforcement

A comparative evaluation of flexural strength of composite resins on glass fibre reinforcement

In the present study, hybrid and microfill composite resins were compared, with and without glass fibre layering at different locations. The specimens (n=90) were prepared by placing the composite into a standard stainless steel split mould (25x2x2 mm) (International Organization for Standardization, 1992; Ellakwa, 2002). Mould was prepared by stainless steel metal because it is non-reactive and maintains the dimensional stability of the test materials. Resin mould may react with resin based polymerizing composite materials and Teflon coated mould may fail to maintain the dimensions of the experimental specimens. Light activation is the most common method of initiating the polymerization process in resin composites for use in restorative dentistry. Light emitting diode (LED) was used to polymerize specimens because the use of LED is preferred over halogen light and plasma argon laser due to no heat production. Multiple overlapping curing was used to polymerize the specimens because the exit window of clinical light cure units is smaller than 25 mm (Chung, 2004). After curing, the specimens were removed from the mould, and were trimmed with BP knife, finished but not polished on the surfaces before testing. All applications were performed in our department, in order to standardize laboratory procedures. The specimen were subjected to thermal cycling to simulate clinical conditions prior to flexural strength test (Queiroz et al., 2012).
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Effect of 2% Chlorhexidine on Shear Bond Strength of Composite Resins to Dentin

Effect of 2% Chlorhexidine on Shear Bond Strength of Composite Resins to Dentin

covered with 2% CHX gel (Ultradent, South Jordan, USA,). The samples wee then covered in cellophane to prevent moisture loss and each sample was placed in a separate container. Dentin was exposed to the understudy materials for 10 days. During this time period, the samples were stored at 37°C. The samples were removed from the incubator every three days and CHX gel was refreshed and the samples were placed again in the incubator. After 10 days, exposed dentin surface was rinsed with saline for five seconds. In groups one and four (exposed to saline and CHX), primer of P90 composite (3M ESPE, St. Paul, MN, USA) was gently applied on the dentin surface by an applicator and was then spread on the surface by gentle dry air spray and light cured for 10 seconds using a light curing unit (LED Turbo South Jordan, USA). Next, the bonding agent of P90 composite was gently applied on the dentin surface by an applicator. The bonding agent was then gently spread on the surface by air spray and light cured for 20 seconds. Next, transparent plastic molds with an internal diameter of 2mm and height of 3mm were placed on the surface and filled with A2 shade of P90 composite. Excess material was removed by a scalpel and the composite was light cured for 20 seconds from four directions (at the sides and from the top for a total of 80 seconds). Plastic mold was gently cut by a scalpel and separated from the composite.
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Utilizing Lignin from Malaysian Bamboo (Semantan) as Partial Replacement of Phenol in Phenol Formaldehyde (PF) Adhesives: Physico-Mechanical Characteristic of Sustainable and Environmental-Friendly Adhesives

Utilizing Lignin from Malaysian Bamboo (Semantan) as Partial Replacement of Phenol in Phenol Formaldehyde (PF) Adhesives: Physico-Mechanical Characteristic of Sustainable and Environmental-Friendly Adhesives

This work focused on utilization of lignin from Malaysian bamboo species locally known as Semantan (Gigantochloa scortechinii) extracted via soda pulping method as partial replacement for phenol during the synthesis of phenol formaldehyde (PF) adhesives. Chemical characterization using spectroscopic method and analysis of thermal properties was carried out. Physico-mechanical characteristic of adhesives (pH, density, solid content), gelation time, dynamic viscosity and lap shear strength of adhesives were also studied. Scanning electron microscopy (SEM) was used to observed the morphology of the cured adhesives. Thermal study showed that addition of lignin during the adhesives synthesis led to reduction of thermal resistance and lowering the carbon residue at elevated temperature. Spectroscopic analysis indicated high degree of similarity in terms of chemical nature for both PF (control) and lignin phenol formaldehyde (LPF). Mechanical characterization performed based on dry lap shear strength indicated that LPF yield satisfactory results, a good indication that synthesis of adhesives with lignin with bamboo lignin as partial replacement for phenol is possible and can provide more economical and sustainable alternative to phenol derived from petrochemicals.
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The effect of duration of finishing and polishing on the surface roughness of two composite resins

The effect of duration of finishing and polishing on the surface roughness of two composite resins

and Composan ceram hybrid composite resin. The results revealed that Composan bio-esthetic nano composite finished with finishing kit for 30 second showed the lower surface roughness average value (Ra=0.307Mm), due to their small filler particle size and their filler arrangement. The average size of nano composite filler particle is 25 nm and nano aggregates of approximately 75 nm 23 . while Composan

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Chemical characterisation of museum-curated ethnographic resins from Australia and New Guinea used as adhesives, medicines and narcotics

Chemical characterisation of museum-curated ethnographic resins from Australia and New Guinea used as adhesives, medicines and narcotics

The integration of this new scientific data with existing ethnographic accounts of these and similar items con- tributes towards a wider understanding of the use of resins in Sahul. This study highlights the use of resin for less-well documented uses such as medicine and nar- cotics, as well as the more commonly referenced adhe- sives. The identification of resin from particular species used for specific purposes can offer insight into past use of natural materials and early adaptation to varying envi- ronments, plant exploitation practices and selection of resin-based materials, early knowledge of chemical prop- erties of resins and the development of technologies, and cultural uses of resins for specific purposes. The methods used in this study show potential for similar identifications of resins from archaeological contexts and highlights the potential for developing a framework to allow the identification of archaeological resins more efficiently and effectively. This work demonstrates that resin analysis of museum artefacts is a useful tool for both ethnographic studies and archaeological research.
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Polymerization Shrinkage of Five Bulk-Fill Composite Resins in Comparison with a Conventional Composite Resin

Polymerization Shrinkage of Five Bulk-Fill Composite Resins in Comparison with a Conventional Composite Resin

Our findings regarding the higher polymerization shrinkage of EXP are in agreement with those reported by Fronza et al [29]. They showed that despite having a high percentage of debonded areas, EXP has a relatively small marginal gap (about 15 µm). It is believed that during polymerization, composites cannot contract along the long fibers in their composition; consequently, they preserve their original horizontal dimensions although the resin matrix tries to contract vertically [29]. This behavior has not been seen with TNB, despite its high mineral content. In fact, this composite showed less polymerization shrinkage stress and a potential
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Evaluation of Enamel and Dentinal Microleakage in Class II Silorane-Based and Methacrylate-Based Resin Composite Restorations Using Specific and Nonspecific Adhesives

Evaluation of Enamel and Dentinal Microleakage in Class II Silorane-Based and Methacrylate-Based Resin Composite Restorations Using Specific and Nonspecific Adhesives

of pure methacrylates as well as the high ability to cross-link [2]. One of the disadvantages of composite resins is the shrinkage resulting from the polymerization reaction, which leads to the accumulation of stress within the material and the tooth-restoration interface. Furthermore, if the stress level exceeds the bonding strength, a gap occurs in this area, which leads to leakage [3]. The attempts to improve the clinical efficiency and to remove internal stresses during the polymerization of methacrylate-based composites have led to the invention of novel polymerization systems such as silorane-based composites [4]. These composites are obtained from the reaction between oxirane and siloxane molecules. These composites have two advantages: firstly, the polymerization reaction is of a ring-opening type, in which the polymerization contraction is low due to the oxirane ring-opening compensatory mechanism [5], and secondly, the presence of siloxane leads to insolubility of the material in the presence of oral liquids, thereby increasing its hydrophobic properties [6]. Oxirane is a 3-membered cyclic ether monomer that is subjected to cationic polymerization; therefore, in addition to less polymerization contraction, cationic polymerization is not inhibited by oxygen in comparison to free radical polymerization [7]. Also, the presence of siloxane monomer in the composite, in addition to hydrophobicity, creates stability in this structure [8].
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