Starch Adhesives Research Articles

Blending water‐soluble aliphatic–aromatic copolyester in starch for enhancing the adhesion of sizing paste to polyester fibers

In this paper, an attempt has been made to ameliorate the adhesion of starch to polyester fibers for warp sizing. The amelioration was achieved by blending newly developed water‐soluble aliphatic–aromatic copolyester (WSACP) in starch because the copolymer had been proved to possess better biodegradability than pure aromatic polyester. The attempt was focused on the determination of the molar ratio of aliphatic units incorporated into WSACP, the amount of WSACP blended, and the analysis of experimental observations from viewpoints of adhesion theory. The adhesion was evaluated in terms of tensile strength and work‐to‐break by using a slightly sized polyester roving method. It was observed that the adhesion depended markedly not only on the molar ratio of aliphatic units to aromatic ones but also on the amount of WSACP blended in starch. With the increase in the ratio, the adhesion did not show much sensitivity to the adhesion until the ratio equaled 30:70. This means that incorporating a certain amount of aliphatic units into water‐soluble polyester does not greatly influence the adhesion. However, the adhesion decreased significantly when the ratio exceeded 30:70. Hence, it can be concluded that the molar ratio of aliphatic units to aromatic ones should be 30:70 in consideration of biodegradability and adhesion. In addition, the adhesion increased as the amount of WSACP blended in starch increased initially. However, excessively increasing the WSACP content reduced the adhesion. The strongest adhesion was observed at a 10% (w/w) WSACP content.

ADHESION OF FOOD POWDERS WITH NONELECTROSTATIC AND ELECTROSTATIC COATING

ABSTRACTThis study investigated the effects of powder resistivity, coating voltage, relative humidity (RH) and coating density on adhesion. Cocoa powder with a high resistivity (1.15 × 1013 Ωm) showed a stronger electrostatic adhesion than starch powder with a medium resistivity (2.56 × 1010 Ωm) and NaCl powder with a low resistivity (7.31 × 105 Ωm). The adhesion of starch and cocoa powders coated at 0, 40 and 95 kV increased with increasing voltage. The adhesion at 0 kV should be dominated by the van der Waals force, at 40 and 95 kV by the electrostatic image force and at high RH by capillary force. Theoretical calculations were in the correct range, but the assumptions in those calculations make them unreliable. For nonelectrostatic coating (0 kV), there was no significant change in adhesion when RH increased from 30 to 60%, while adhesion increased when RH increased from 60 to 80%. For electrostatic coating, the adhesion decreased when RH increased from 30 to 60%, but the adhesion at 80% RH was larger than the adhesion at 30 and 60% RH. For both nonelectrostatic and electrostatic coating, the adhesion force decreased as coating density increased to 1.0 mg/cm2, but there was no significant change from 1.0 mg/cm2 to 2.0 mg/cm2.PRACTICAL APPLICATIONSThe adhesion of seasoning powders on snack foods plays an important role in the product quality, but insufficient adhesion between food powders and the surface of snacks results in the seasonings falling off the snacks, leading to a poor distribution and waste of seasonings. This study suggests that the adhesion between food powders and targets can be effectively improved by controlling the properties of the powders, as well as optimizing coating conditions. For example, using food powders with a high resistivity and high voltage during electrostatic coating and increasing relative humidity will increase adhesion.

Development of a Starch Adhesive for Corrugated Board under Room Temperature

The use of starch as a renewable and biodegradable adhesive is becoming increasingly attractive because of the environmental concerns about the industrial wastes generated from petroleum products and the growing awareness of the potential deleterious consequences of greenhouse gas emissions from these activities. Starch adhesive is most extensively used in corrugated board industry because of the abundant supply, low cost, renewability, biodegradability, and ease of chemical modifications. Starch adhesive has great effect on the performance, production technology and manufacturing cost of the corrugated board. It is of great importance to develop starch adhesive with stable properties, high performance, good viscosity, fast curing speed to meet the market requirement. In this paper, oxidation of starch by sodium hypochlorite under aqueous alkaline conditions with the aid of the catalysis of nickel sulphate at room temperature was investigated. The effects of sodium hypochlorite loading and caustic soda dosage on the properties of the starch adhesive were examined. Optimization of starch oxidation is desirable to achieve the highest initial tack and bonding strength. The optimum synthesis condition was obtained. Under the optimum condition, Under the optimum condition, 98.7% of the initial tack and 11.4 N/25 mm of the bonding strength were obtained respectively.. The modified starch adhesive showed great potential for industrial application.

Preparation of the Plywood Using Starch-based Adhesives Modified with blocked isocyanates

The purpose of the research was to prepare environment friendly plywood using starch adhesives modified by blocked isocyanate. Blocked isocyanate and auxiliary agent were used to modify starch. The influence factors of the bonding strength and water resistance of starch adhesive were studied by different solid content, adding additives and adding blocked isocyanate. The results show that starch and blocked isocyanate adhesive to join the ratio of 100/20, the dry bonding strength the most, while the starch adhesives and the ratio of blocked isocyanate to join 100/25, the wet strength the most. Bonding strength and water resistance was improved significantly by adding additives and isocyanates to starch adhesive. Plywood bonding strength from the performance of integrated cost considerations, the optimum ratio of additives added 4% and 6%.

Shear Refinement of Formaldehyde-Free Corn Starch and Mimosa Tannin (Acacia mearnsii) Wood Adhesives

The aim of this work was to reduce the viscosity of formaldehyde-free corn starch–mimosa tannin wood adhesives, without adversely affecting the mechanical properties of the product. The reduction of viscosity was achieved using shear refinement. The study focused on the physical phenomena before cross-linking of the wood adhesive. The physical (rheological characterization) and mechanical (bond strength) properties of formaldehyde-free corn starch and mimosa tannin wood adhesives were measured. The results showed that the shear refinement (290 rpm and 5 min, optimal conditions) reduced the viscosity of the corn starch–mimosa tannin wood adhesives (from 100 000 to 458 Pa s) with the advantage of being stable over time. Mechanical tests showed that the shear refinement did not influence the mechanical properties of corn starch–mimosa tannin wood adhesives.

Adhesive Properties of Cyanoethyl Starch

Cassava starch was cyanoethylated to different degrees of substitution (DS) and then used in adhesive preparations. The adhesives were used in bonding wood substrates and the adhesive strength of the bonded substrates was evaluated using a tensometer. The effects of the DS, solids content, pH and moisture on adhesive strength were investigated. The adhesive strength increased with increasing DS; with respect to the percentage solids, it increased to a maximum and then decreased again; with pH, it showed a minimum at a neutral pH; while it decreased with length of exposure to saturated moisture conditions. The experimental data were subjected to regression analysis to find the best fitting models. The results showed that the adhesive strength varied polynomially with DS (R 2 = 0.97), pH (R 2 = 1.0), percentage solids content (R 2 = 0.94), and exponentially with the length of exposure to saturated moisture conditions (R 2 = 0.96). Cyanoethylation significantly enhanced the adhesive property of starch (p < 0.05) and the cyanoethyl starch adhesives were found effective for bonding wood. However, cyanoethyl starch adhesive is not suitable as structural adhesive in a high moisture environment. The performance of cyanoethyl starch adhesive was compared with two commercial adhesive pastes.

【報文】 段ボールシート製造用ノーキャリヤー(NC)型澱粉接着剤における加熱糊化時の熱量的挙動と接着剤の調製に及ぼす添加苛性ソーダの影響

高澱粉濃度領域で濃度を変えて使用される段ボールシート製造用NC型澱粉接着剤において，加熱糊化時と接着剤調製時の添加苛性ソーダ比率の影響を，従来多く使用されてきた対接着剤苛性ソーダ重量濃度や対使用水重量濃度に換えて，対澱粉当たりの重量比率，さらには同モル比率(グルコース残基当たりの苛性ソーダモル数)を用いて検討した。澱粉懸濁液と接着剤とを対比して調べた糊化開始温度(Ts)は，苛性ソーダ添加モル比率の増加により共に温度低下し，懸濁液では特異的に著しく低下した。糊化の進行と完了を示す糊化ピーク温度(Tp)と糊化完了温度(Tc)は,懸濁液と接着剤とで相異はなく，糊化時の苛性ソーダ添加モル比率の増加に従って同様に温度低下した。粒径分布比較と懸濁液Tsの特異な温度低下から，接着剤では苛性ソーダに鋭敏に反応する一部の澱粉の糊化膨潤は調製時に既に先行しており，NC接着剤の調製では増粘にこの一部の澱粉を利用していると考えられた。NC型接着剤中の溶解澱粉比率と澱粉の膨潤度合との両方に，調製時苛性ソーダ添加モル比率と直線的な比例関係があった。2つの近似直線を苛性ソーダ無添加懸濁液のそれぞれの値に外挿して，接着剤調製時の溶出と膨潤開始の閾値として8.3mol%と8.9mol%の苛性ソーダ添加モル比率を得た。懸濁液と接着剤の糊化エンタルピー(ΔH)は，接着剤には調製時苛性ソーダ添加モル比率を用いると，同一2次曲線によく近似して9mol%前後から急減した。接着剤ΔHの減少割合と，溶解澱粉比率と膨潤度合の増加割合との比較から，接着剤ΔHの顕著な減少は，調製増粘時の高い苛性ソーダ添加モル比率により，一部澱粉の糊化膨潤だけではなく，残りの澱粉内結晶構造も減少したためと推定された。しかし，接着剤のTpとTcの温度低下は懸濁液と変わらず,結合力の高い大部分の結晶構造は維持されていると考えられた。

Preparation of Plywood Using Starch Adhesives Modified with Isocyanate

The purpose of the study was to manufacture plywood using starch adhesives modified by isocyanate, the influence factors on the bonding strength and water resistance of starch adhesive were studied by different solid content, adding additives and adding isocyanate. X-ray photoelectron spectroscopy (XPS) analysis was used to characterize the chemical structure of bonding interface. The results show that the bonding strength of starch adhesive was increased significantly when solid content increased to 50%. Bonding strength and water resistance were improved significantly by adding additives and isocyanates to starch adhesive. The analysis of XPS indicated that the chemical bonding derived from the reactions of isocyanate was the key factor to increase bonding strength and water resistance.

Water resistance, mechanical properties, and biodegradability of poly(3‐hydroxybutyrate)/starch composites

AbstractComposites of poly(3‐hydroxybutyrate), P(3HB), and starch were prepared by solution casting technique. To improve adhesion of starch to P(3HB), stearic acid was added as a compatibilizer and glycerol as a plasticizer. The water resistance, mechanical, and biodegradable properties of the P(3HB)/starch composites were studied. Diffusion and penetration coefficients of water increased with increasing starch content in the composites. The results showed that the elastic modulus and strain at rupture of the P(3HB)/starch composites were enhanced by increasing starch content upto 10 wt % and the tensile strength increased from 21.2 to 93.9 MPa. The presence of starch content higher than 10 wt % had an adverse effect on the mechanical properties of the investigated composites. The biodegradation rate using Actinomycetes increased proportionally to the starch content in the composite and accelerated in a culture medium of pH ≈ 7.0 at 30°C. Enzymatic degradation experiments showed that lipase produced by Streptomyces albidoflavus didnot degrade P(3HB)/starch composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Preparation and flexural properties of biomimetic laminated boards made from starch and maize straw fibers

In this study, maize stalk tegument separated from the maize pith was crushed to obtain the fiber. The cross-linking maize starch adhesives considering four main factors (water content, gelatinization temperature, NaOH as gelatinization agent and Na2B4O7·10H2O as cross-linking agent) with three levels were prepared based on an orthogonal test scheme L9(34) in order to increase the water-resisting property and the bonding strength of the common maize starch adhesives. The bonding properties of maize starch adhesives were characterized using shearing strength under compression loading. Physical models of fiber reinforced composites were established according to the microstructure analysis of the four species of insects’elytra including Protaetia orentalis, Copris ochus Motschulsky, Anoplophora chinensis and Cytister bengalensis Aube, which will provide the biomimetic models for the biomimetic laminated boards. The maize stalk fiber biomimetic laminated boards were prepared based on the structural models of the elytra material. The flexural strength and flexural elastic modulus of the biomimetic boards were examined. The results showed that the flexural strengths of the single layer jute fiber, -reinforced maize stalk fiber boards and the dual layer jute fiber reinforced maize stalk fiber boards are higher than those of the common maize stalk fiber boards and the other three groups of jute fiber hybrid reinforced stalk fiber boards because of the biomimetic laminated design. Keywords: maize stalk, biomimetic, elytra, starch, laminated board, flexural property DOI: 10.3965/j.issn.1934-6344.2009.02.024-031 Citation: Zhang Fu, Wu Na, Tong Jin, Zhou Jiang, Yang Xin, Ma Yunhai, Chen Donghui, Sun Jiyu. Preparation and flexural properties of biomimetic laminated boards made from starch and maize stalk fiber. Int J Agric & Biol Eng, 2009; 2(2): 24

Effects of Preservative Agents on Cassava Starch Adhesives

This research seeks to explain the effects of various preservative agents on starch adhesives. Adhesives were produced from cassava starch by gelatinizing with sodium hydroxide and heat. Modifications and addition of preservative agents to these adhesives were done in order to obtain a suitable working consistency and also to prolong their shelf life. Starch adhesives formed by gelatinizing with sodium hydroxide possesses good working properties, but requires mild alkalinity (pH 9.60). The stability of the final adhesives produced was also found to be dependent on the pH. At pH 9.60, the percentage decrease of viscosity after 18 days was 69.6%, while at pH 3.2, it was 98.85%. The shelf life was also controlled by adding various preservative agents to the adhesives pastes. The preservative agents added were formaldehyde, benzoate and butraldehyde. The addition of 2g of these preservative agents per 100g adhesives reduced the percentage decrease of viscosity by as much as 40% compared to that when preservative agents were not added.

Application of hydrophilic starch‐based coatings on polyethylene surfaces

AbstractCoatings were applied to polyethylene (PE) film surfaces by spraying formulations prepared from a jet cooked dispersion of waxy cornstarch, a water‐born epoxy resin, a wax emulsion, and a fluorinated surfactant. The air‐dried coatings were comprised of discontinuous areas of polymer that adhered tightly to the PE surface. Although the starch component separated rapidly from the coating when the film was placed in water at room temperature, heating the coated film for 24 h at 80°C increased the adhesion of starch and produced a surface coating that remained uniformly wet when the film was placed in water. Most of the starch, however, could be still be removed by gently rubbing the wet surface. If melamine‐formaldehyde resin was added to the formulation as a crosslinking agent for starch, and the coated film was then heated for 24 h at 80°C, most of the starch remained bonded to the wet coating, even after the surface was gently rubbed. Identification of successful spray application techniques and formulations will allow the development of commercial production methods for starch‐coated PE films and similar products. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

数種の段ボール製造用スタインホール型澱粉接着剤高温糊化液物性について

メイン部とキャリヤー部からなるいわゆるスタインホール型(SH)段ボール製造用澱粉接着剤の高速接着時の必要物性を明確にするために，85℃で高濃度澱粉糊化液のせん断ひずみ初期のせん断弾性率，最大せん断応力値，せん断応力パターンと粘度をトウモロコシ，ハイアミローストウモロコシ(ハイロン-5)，ワキシートウモロコシ，小麦，馬鈴薯，甘藷，タピオカの7種の澱粉について測定した．7種澱粉懸濁液糊化液の物性は澱粉種により大きく異なり，これら懸濁液糊化液と，7種の各澱粉をメイン部に使用してキャリヤー部にトウモロコシを用いたSH接着剤糊化液との85℃での物性比較から，SH接着剤の糊化液物性はメイン部澱粉懸濁液糊化液物性を大きく反映し，キャリヤー部糊化澱粉水溶液の添加はこれらの物性を増強した．せん断弾性率と最大せん断応力値は澱粉種により差異があった．また，澱粉濃度の増加により，85℃7種澱粉懸濁液糊化液の各せん断弾性率と最大せん断応力値は指数関数的に増加した．さらに，糊化液のせん断弾性率が表す弾性と最大応力までのひずみ量が表す柔軟性や流動性は個々の澱粉種により澱粉濃度増加による変化が特徴的に異なり，四つのタイプに分類された．弾性率が高い順序と最大応力までのひずみ量が小さな順序で整理すると，弾性率が高く最大応力までのひずみ量が少ないハイロン-5と，弾性率がやや高く最大応力までのひずみ量がやや少ない小麦・トウモロコシと，弾性率がやや低く最大応力までのひずみ量がやや大きな馬鈴薯・甘藷・タピオカと，弾性率が低く最大応力までのひずみ量の大きなワキシーと異なる四つのタイプに分類された．その結果，SH澱粉接着剤糊化液物性は使用する澱粉種によりその物性が異なることがより明白となった．また，弾性率は糊化澱粉粒の形状保持が良いハイロン-5や地上澱粉で高くなり，最大応力までのひずみ量はワキシーや地下澱粉で大きくなった．しかしながら，7種澱粉をメイン部に用いるSH接着剤にて片段試料と表ライナー原紙を170℃のホットプレートで加熱貼合して，ただちに剥離した際の初期接着性には，澱粉種による大きな相違はなかった．これらのことから，初期接着性には澱粉接着剤糊化液の澱粉粒構造の存在や弾性率の高さや最大応力値が最も優先する条件ではないと考えられた．

段ボール製造用スタインホール型澱粉接着剤の初期接着性と高温糊化液物性に及ぼす苛性ソーダ濃度の影響について

段ボール製造用スタインホール型澱粉接着剤の初期接着性と高温糊化液物性に及ぼす苛性ソーダ濃度の影響について

Carbamoyl ethylation of starch for enhancing the adhesion capacity to fibers

AbstractThe influence of starch carbamoylethylation upon the adhesion capability of starch to pure cotton, all polyester, and polyester/cotton blend fiber substrates were investigated. The carbamoylethyl starch was prepared by the reaction of starch with acrylamide in an aqueous dispersion. The capability was evaluated in terms of the maximum strength and work‐to‐break of a roving impregnated with the starch pastes. The mechanical behaviors of the adhesive layers were estimated through a method by casting starch films and then by measuring their behaviors under controlled condition. It was found that the carbamoylethylation is an effective means for enhancing the adhesion of starch to fibers. No matter what type of the fibers is used, the adhesion capability obviously enhances compared with those of unmodified starch, even if the degree of substitution is at a very low level. The capacity increases steadily as the modification extent increases. Moreover, the experimental results are also discussed and analyzed especially through the failure type, internal stress, stress concentration, and mechanical behaviors of the adhesive layers among fibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

The physicochemical properties of flour samples from the roots of 31 varieties of cassava

Flours were prepared from 31 cassava varieties and evaluated for their physicochemical properties and pasting characteristics. The results showed that starch content ranged from 67.92% for sample 91/0055 to 88.11% for sample I93/0665. Amylose content of cassava flour varied from 10.9% (94/0050) to 44.3% (I93/0548). The cassava flour had low swelling power values ranging from 5.87(Abasafitaa) to 13.48(I89/02184). Water binding capacity varied from 113.66% for variety 92/0427 to 201.99% for variety 90/00330. Gelatinization temperature was in the range of 66.8 °C for Gblemo Duade to 70.4 °C for I82/0326 with peak temperatures varying between 73.1 °C (92/0035) and 84.5 °C (94/0107). The cyanogenic potential (CNp) ranged from 0.58 to 20.0 mg HCN per 100 g of dry weight with 081/00356 having the highest value, while 90/00330 had the lowest. From the data obtained it can be concluded that cassava varieties should not be abandoned because of poor cooking quality and high cyanogenic potential. These varieties could be used for other purposes such as starch production, glucose, adhesives, fuel alcohol, animal feed and other industrial uses.

Curing starch based adhesives: microwave or conventional

The field of microwave material processing is inherently multidisciplinary linking electromagnetism and material science. There are a variety of manufacturing industries utilising microwave power as heating drying source, several cases incorporating hybrid-heating technologies in processes such as paper, rubber, polymers, foodstuff and brick. In reference to starch based adhesive bonding, microwave processing produced improved adhesive joint properties due to the incorporations of dielectric heating methodologies. Relative to the ageing steam heated hot plate, which has been plagued with inconstancies such as; operational efficiency, economics of scale, factory floor requirements and throughput, the science of microwave curing of wheat base starch adhesive is based on the relationship between the interaction of electromagnetic energy and the dielectric properties of the materials. Microwave heating possesses some unique characteristics, which are not found in other types of heating. In volumetric heating, heat is generated principally in the product and not on the kiln walls or atmosphere. Hence the heat losses from the oven walls to the surroundings are much lower and results in reduced running costs. The objective of this article is to establish a comparative material characterisation between microwave and conventionally cured wheat base starch adhesives, also to provide a bonding strength analysis. All references made to microwave heating also apply to microwave curing.

Industrial applications of potato starch products

Traditionally, the starch industry mainly sells its customers the functions of thickening and adhesion. Modern applications and processing developments are giving rise to an increasing need for further product adaptations and refinement, although one of the oldest applications, the starch adhesives, have for the most part maintained their position. The paper industry has seen the large-scale introduction of cationic starches as a wet-end additive. This development has been strongly supported by recycling and the re-use of waste paper. Starch as a component in food products is a daily experience for everyone. For modified starches, attention is nowadays focused on such properties as thickening, stability, shelf-life, texture and expansion. Warp sizing and fabric printing are the principal applications for starch derivatives in the textile industry, where it is a temporary easily removable processing aid. In addition to these four main areas of application, there are a number of other fields where starch products have a special role. Good examples are fluid loss control during deep-well drilling for oil and gas, and flocculation in the purification process for drinking-water.

Change in the Rheology of Starch Adhesive During Gelatinization

AbstractIn this paper the viscosity increase of the starch paste during gelatinization is examined. Upon heating, raw starch granules gelatinize and the paste viscosity of the starch adhesive increases dramatically. Bonding develops further through the dehydration of the gelatinized starch by the board. Bond setting of carrier‐type (mixture of dissolved and raw) starch on paperboard in the corrugated board operation is thought to result from a combination of thermal gelatinization and dehydration by the board.

The manufacture and use of Japanese wheat starch adhesives in the treatment of Far Eastern pictorial art

The manufacture and use of Japanese wheat starch adhesives in the treatment of Far Eastern pictorial art