Starch Graft Research Articles

New Route for Novel Polycarboxylic Starch Hybrid

Starch was polymerized with methacrylic acid (MAA) to different magnitudes of poly (MAA) using potassium persulphate/sodium thiosulphate redox initiation system. The polymerization products are referred to as “composite”. The latter consists of poly (MAA)-starch graft copolymer, poly (MAA) in the form of homopolymer, oxidized starch brought about under the influence of the initiator and intact starch. At this end, the composite, the copolymer, and the untreated (native) starch were subjected to carboxymethylation under different conditions and the rheological properties of these starch—based on products before and after carboxymethylation examined. Results obtained disclosed that the susceptibility of these products toward carboxymethylation follows the order: native starch > Copolymer > composite. Meanwhile, these products exhibit non-Newtonian thixotropic behavior before carboxymethylation; and their rheology signifies the order: Composite > copolymer > native starch whereas after carboxymethylation these products are characterized by non-Newtonian Pseudoplastic behavior. For a given rate of shear, the apparent viscosity follows the order: native starch > composite > copolymer > carboxymethyl composite > carboxymethyl starch > carboxymethyl copolymer, in contrast with pseudoplasticity which reveals an opposite order. It was also shown that the apparent viscosity increases by increasing poly (MAA) in the copolymer and composite and that redrying of the copolymer and the composite after normal precipitation and drying causes a considerable enhancement in the apparent viscosity of these products.

Gamma radiation-induced grafting of acrylamide and dimethyl diallyl ammonium chloride onto starch

Corn starch graft copolymers were prepared from acrylamide/dimethyl diallyl ammonium chloride binary monomers (AM/DMDAAC) by a simultaneous radiation grafting method, and were characterized by FTIR and 1H NMR techniques, weight measurement and titration method. The copolymers with high grafting ratio and high grafting efficiency of binary monomers were achieved at absorbed doses of 2kGy and 3kGy using a 6:9.8:4.2 (w/w/w) ratio of starch/AM/DMDAAC, but their cationic degrees were low. Grafting ratio, grafting efficiency and cationic degree of the copolymers increased with increasing AM content in comonomer mixtures and then decreased at 3kGy using a 6:14 ratio of starch:total comonomers, but their cationic degrees generally decreased with increasing AM content. The grafting ratio, the grafting efficiency and the cationic degree of the copolymers increased, but the grafting efficiency of DMDAAC decreased with varying starch/(AM+DMDAAC) ratio from 6:3 to 6:18 at 3kGy by using a fixed 7:3 ratio of AM:DMDAAC.

Synthesis of Starch Graft Copolymer Dispersant and its Application Performance in Coal-Water Slurry

In this study, a new starch graft copolymer dispersant for Chinese Shenhua coal-water slurry (CWS) was prepared by radical polymerization using styrene sulfonate (SSS), hydroxyethyl acrylate (HEA) and methyl acrylic acid (MAA) as graft monomers in oxidation-reduction initiator system. The apparent viscosity, static stabilization and rheology of Shenhua coal-water slurry prepared with the dispersant have been were investigated. The experimental results demonstrate that the CWS gives the minimal viscosity of 826 mPas at coal concentration of 66 wt%, dispersant dosage of 0.5 wt% and shear rate of 100 s-1. Bleeding ratio tests indicate the starch graft copolymer can stabilize the slurry. The rheological behavior of the prepared CWS can be described by the pseudo-plastic fluid model. On the basis of the above, the starch graft copolymer dispersant has broad prospect for the application for CWS.

Morphology and Mechanical Properties of Compatibilized Bio-sourced PA/Plasticized Starch Grafted PP Ternary Polymer Blends

AbstractPolymer blends of biosourced polyamide (Rilsan XD) and thermoplastic starch grafted polypropylene (LAB4270) were processed by means of a co-rotating twin-screw extruder, using a solid epoxy resin (D.E.R. 664UE) as a compatibilizer. Morphologies as well as rheological, thermal and mechanical properties of the blends were characterized. The morphology of the reference blend was characterized by nodules of the micron order of magnitude of the dispersed phase (LAB4270) embedded in the polyamide matrix. Even though the morphologies of the blends were not impacted by the addition of the epoxy resin, the mechanical properties as well as the impact resilience were proved to be enhanced. The thermal properties of the blends were as well influenced. A shift of the crystallization temperatures and a decrease of the crystallization enthalpies of both the polypropylene and the PA XD were observed. Thus the addition of the epoxy resin as compatibilizer had proved to be truly effective to obtain a material mostly biosourced with mechanical properties that tend towards combined optimal properties of the different components of the blend.

Synthesis and Evaluation of Starch Graft Copolymer Applied as Dispersant in Coal-Water Slurry

In this paper, a starch-based dispersant for Chinese Shenhua coal-water slurry (CWS) was synthesized by radical polymerization using styrene sulfonate and acrylic acid as graft monomers in oxidation-reduction initiator system. Chemical structure and thermal performance of the copolymer were investigated by Fourier Transform Infrared Spectrum (FT-IR) and Thermogravimetric Analyzer (TGA). The rheological characteristics of the slurry were studied by varying dispersant dosage and shear rate，and the results show, At coal concentration of 66 wt%, dispersant dosage of 0.4 wt% and shear rate of 100 s-1, the CWS gives the minimum viscosity of 848 mPa•s. Bleeding ratio tests indicate the dispersant can stabilize the slurry. Based on the above, the starch-based dispersant has due structure and a bright prospect for the application for CWS.

Novel Environmentally Friendly Copolymers Carboxymethyl Starch Grafted Poly(Lactic Acid)

Modified natural polymers have been gaining increasing scientific interest for many years. In this study carboxymethyl starch (CMS) was grafted with L(+)-lactic acid (LA) in different molar ratios CMS/LA (1/36, 1/22 and 1/12), resulting carboxymethyl starch-g-poly(lactic acid) (CMS-g-PLA) copolymers. The grafting reaction was carried out by solution polycondensation procedure in toluene and stannous 2-ethyl hexanoate Sn(Oct)2 as catalyst was utilized. Poly(lactic acid) (PLA) was synthesized in the same conditions with the copolymers for comparative analyses of the physico-chemical and thermal properties. The copolymers and PLA were structurally and morphologically characterized by FT-IR, 1H-NMR spectroscopy, WAXD and SEM analyses, taking CMS as reference. The molecular weight of the copolymers, CMS and PLA were determined, using a dynamic light scattering technique. The thermal behavior of the products was studied by DSC and TG-DTG analyses. The CMS-g-PLA graft copolymers exhibited lower Tg and thermal stability than pure CMS.

Starch‐graft copolymers of N‐vinylformamide and acrylamide modified with montmorillonite manufactured by reactive extrusion

AbstractGraft copolymers of potato starch with acrylamide, acrylamide, and acrylic acid or N‐vinylformamide in the presence of 1–16 wt % montmorillonite were manufactured via reactive extrusion. XRD and TEM measurements exhibited intercalated structure of clay dispersion (d001 distance up to 2.3 nm). The influence of graft polymer(s) system and montmorillonite content on thermal properties, water sorption as well as polyvalent metal cation (Cd2+ and Fe3+) sorption of obtained starch graft copolymers has been determined. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

고압처리 찹쌀전분의 이화학적 특성

찹쌀전분의 고압처리시 pH 3~10 조건에서 고유점도는 1.328~1.426 ml/g 범위로 원료전분(1.15 ml/g)보다 낮았다. 특히, 고유점도는 산성 및 알칼리성 조건에서 감소하였다. 전분의 호화과정 중 열에너지량을 나타내는 호화엔탈피는 pH 3, 4 및 5 조건에서 고압처리한 찹쌀전분이 각각 13.86, 13.47 및 13.42 J/g으로 원료전분(16.3 J/g)보다 낮은 값을 보였다. 찹쌀전분의 호화온도 및 엔탈피 감소는 고유점도가 낮아지는 현상과 일치하였다.

Recent advances in chemistry and biotechnology of starch derivatives

The review focuses on the most important studies performed during the last eight years on the physical and chemical modifications of starch, starch graft copolymers, and starch ethers; on the development of biodegradable starch-based materials; and on various applications of numerous starch derivatives. An analysis of the recent publications allows the conclusion that considerable advances have been made in the chemistry and technology of starch derivatives as biodegradable “green” reagents and products, which are becoming increasingly important for technological applications due to the wide occurrence of starch, the ease of its processing, and its nature as a renewable resource.

Application of Cationic Starch Graft Copolymer in Flocculating of Wastewater from Bleaching

Corn starch, acrylamide and diallyl dimethyl ammonium were used as the raw materials and ammonium persulfate as initiator, cationic starch graft copolymer was prepared, and then the prepared cationic starch graft copolymer is applied to flocculate wastewater from bleaching. The results show that The flocculation of cationic starch graft copolymer to wastewater from increases first and then decreases after the reach of the peak with the increase of the cationic degree of the cationic starch graft copolymer, addition amount, flocculating temperature and flocculating time. When the cationic degree of the cationic starch graft copolymer is 27.38%, the addition amount is 7.5%, the flocculating temperature is 50°C and the flocculating time is 30min, the flocculation of cationic starch graft copolymer to wastewater is the best. The flocculation of alum/cationic starch graft copolymer is better than cationic starch graft copolymer is used only. Introduction

Study on Cationic Starch Graft Copolymer in Papermaking Wastewater Treatment

Paper industry is one of the major environmental pollution industries in china, pulp and paper industry wastewater discharge amount is from 10% to 12% of the national total wastewater discharge amount. Cationic starch graft copolymer was prepared in laboratory and used to treat papermaking wastewater. The effects of its cationic degree, dosage, flocculation temperature, flocculation time and the combination with alum on papermaking wastewater treatment were investigated. It was found that the best flocculation in the treatment of papermaking wastewater is achieved when cationic degree of cationic starch graft copolymer is 27.38%, adding amount is 15mL, flocculation temperature is 50°C and the mass ratio of alum to cationic starch graft copolymer is 2: 1. The flocculation of composite flocculant made up with alum to cationic starch graft copolymer to papermaking wastewater is much better than only cationic starch graft copolymer is used.

Preparation and Performance of Bio-Adhesive Based on Acorn Starch Graft Glycidyl Methacrylate

For improving the performance of acorn starch (AS) based bio-adhesive, AS graft glycidyl methacrylate (AS-g-GMA) adhesive was prepared in this paper. The properties of the AS-g-GMA adhesive were studied by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) measurement. The bonding strength of the plywood bonded by AS-g-GMA adhesive was measured according to Chinese National Standards methods to evaluate its water resistant. FTIR results indicated that GMA was grafted on the AS successfully. The bonding strength of the plywood bonded by AS-g-GMA adhesive showed lower curing temperature, better bonding strength, and water resistance comparing with that of control. The water resistant could reach type II grade (63°C water bath 3h) plywood requirement when the glycidyl methacrylate adding amount was 6% based on AS.

Synthesis of Lactic Acid Grafting Starch Copolymer Catalyzed with Stannous Chloride

A convenient method to synthesize starch/lactic acid copolymer was studied in this work. The lactic acid grafting starch copolymer was directly prepared by reaction of cornstarch with lactic acid catalyzed with stannous chloride (SnCl2). The structure of starch/lactic acid copolymer was characterized by IR and 1H-NMR, and its morphology was seen by SEM and XRD. The effects of mass ratio between starch and lactic lacid, amount of catalyst and reaction time on the grafting degree were also studied. The result showed that the best grafting degree could reach 12.8％ with 1:6 as the mass ratio between starch and lactic acid and 1.5％ as amount of catalyst accounting for consumption of lactic acid by reaction at 90 oC for 7 h.

Preparation and Properties of Cationic Graft Starch Sizing Agent

In this article, a new kind of starch sizing agent, cationic graft starch [CS-g-P(AM-co-HEMA-co-BA)] was synthesized. Its structure was identified by Fourier transform infrared spectroscopy (FTIR). The results of sizing experiment show that polyester/cotton blended yarn (T/C 55/45) sized with cationic graft starch exhibits better tensile strength, abrasion resistance and lower hairiness counts than cationic starch and PVA. This new starch sizing agent can be an ideal substitute for PVA.

Synthesis and characterization of polyacrylonitrile pregelled starch graft copolymers using ferrous sulfate‐hydrogen peroxide redox initiation system as surface sizing agent

AbstractA graft copolymer was synthesized by graft copolymerization of starch with styrene (St) and butyl acrylate (BA), using ferrous sulfate‐hydrogen peroxide redox initiation system. The starch was pregelled in the presence of acrylonitrile (AN) in aqueous alkali at high temperature before graft polymerization. Major factors affecting the polymerization reaction were investigated. It was found that a graft copolymer with higher percentage conversion (PC), graft efficiency (GE) and graft percentage (GP) was obtained by controlling the initiator concentration, concentration, and ratio of monomers and polymerization temperature. The optimum conditions were as follows: H2O2 concentration, 12%; monomer concentration, 120%; St/BA ratio, 1 : 1; polymerization temperature, 65°C. Fourier transform infrared spectroscopy and NMR analyses were used to gain information on the structure of the products. It was demonstrated that St, BA, and AN had been successfully grafted onto starch and CN had been saponified into CONH2 and COO− to a certain degree when pregelling. Scanning electron microscope micrographs showed the coarse structure and broad network. The graft polymerization took place on the surface of starch granule and led to amorphization of the starch structure. Graft polymer had better thermal stability and was endowed with pseudo‐plasticity. It was observed that the starch graft copolymer offers good properties such as water resistance as surface‐sizing agent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Preparation of poly (DMAEM)-cross linked pregelled starch graft copolymer and its application in waste water treatments

Pregelled starch (PS) was first cross linked with epichlorohydrin (ECH) to obtain insoluble cross-linked pregelled starch (CPS). The latter was graft co-polymerized with different amounts of dimethylaminoethyl methacrylate (DMAEM) using potassium permanganate/sulphuric acid redox system. This was done to obtain six levels of poly (DMAEM)-cross linked pregelled starch graft copolymers (PDMAEMCPS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMCPS 1 to PDMAEMCPS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form polymer–metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and starch dose were studied in detail. It was found from the obtained results that; the residual metal ions removal from their aqueous solutions increased with (a) increasing the extent of grafting of PDMAEMCPS i.e. from PDMAEMCPS 1 to PDMAEMCPS 6; (b) increasing the pH of the metal ions solution complex from 1 to 8; (c) increasing the starch dosage from 0.25 to 2.0% (w/v), then leveled off thereafter and (d) increasing the time of the reaction up to 20min then leveled off after that. On the other hand, Pb, Cd and Hg ions were also removed from their solutions with different extent. Furthermore, the prepared copolymer could be recovered by washing the metal ions from the complex with weak acid 1N HNO3 (pH 2) and the metal-binding activity of the starch was slightly reduced by this process. Finally, the ability of PDMAEMCPS to remove three types of acid dyes from their solutions was also reported.

Studies on Grafting Copolymerization of Lactic Acid onto Cornstarch Catalyzed with Sodium Hydroxide

A convenient method to synthesize starch/lactic acid copolymer was studied in this work. Copolymer of starch graft with lactic acid (LA) was directly prepared by reaction of cornstarch with lactic acid in sodium hydroxide (NaOH) aqueous solution as a catalyst. The product was characterized by IR and WAXD, and the good adhesion between the two components has been observed by SEM. The results showed that the highest grafting degree could reach 33.60% when the graft copolymerization was carried in 0.40 mol·L-1 NaOH aqueous for 9 h at 90°C with the 1: 5~6 ratio of starch and lactic acid.

Synthesis of Cationic and Ampholytic Starch Graft Acrylamide and their Aqueous Salt Absorption

Acrylamide was grafted onto starch using ceric(IV) ion as initiator. Starch–graft-polyacrylamide was then modified through Mannich reaction using formaldehyde and diethylamine to give poly(N, N′-[(diethylamino) methyl]-acrylamide). The modified-graft copolymer was quaternized using different reagents; methyl iodide, n-butylbromide, sodium chloroacetate and propane sultone to give cationic and ampholytic graft materials. The absorbing properties of the produced materials toward deionized water and aqueous salt solutions were investigated. Studies of the absorbing properties of polyampholytes have revealed that these materials do not shrink upon increasing salt concentration. Kinetics of swelling in deionized water is also discussed.

Preparation of Potato Starch Graft Copolymer and its Application in Functional Coatings

A new kind of self-cross-linked potato starch graft copolymer (PoSt-g-P) was prepared successfully by emulsifier-free emulsion polymerization, in which methyl methacrylate (MMA), acrylic acid (AA) and butyl acrylate (BA) were used as main monomers, and diacetone acrylamide (DAAM) as functionality monomers. The keto-carbonyl group in the potato starch graft copolymer /DAAM could react with adipic dihydrazide (ADH) at ambient temperature to form cross-linked thin film. The film properties of emulsion were measured, which showed excellent properties in hardness, gloss and water resistance. The humidity-sensitive coatings (PoSt-g-P-C) were prepared by the self-cross-linked PoSt-g-P, pigments and fillers. Adipic dihydrazide was used as a cross linking agent and assistant. Its humidity controlling properties were also measured and shown high activity in increasing humidity and dehumidify.

Preparation of Grafting Starch by HRP Catalyst and it’s Application in Leather Tanning Process

Two grafting starch was obtained by grafting copolymerization of two synthetical vinyl monomers using HRP/H2O2 as catalyst. The structure of vinyl monomers was verified by 1H-NMR.The grafting polymer was proof by structures were verified by FTIR. The effect of mass ratio of starch and vinyl monomer on the grafting efficiency (GE) and grafting percentage (GP) was studied. The highest GE and GP of the first grafting starch was 35% and 32%, 59% and 50% for the second grafting starch when the vinyl monomer ratio was 9%. The molecular mass tested by GPC for the two kinds grafting starch with highest GE and GP were 54 600 and 63 970. The two mostly grafted starches were used as retanning agent. The increase ratios in thickness were 18.1% and 18.6% respectively and the tanned leather has excellent softness and flexibility.