EcoSynthetix (Canada)

Abstract Pickering miniemulsion polymerizations of styrene using octenyl succinic anhydride (OSA) and dodecenyl succinic anhydride (DSA) modified starch nanoparticles (SNP) (~20–25 nm) were conducted. The effect of different degrees of substitution (DS), alkyl chain length, concentration of Pickering emulsifier (PE), and pH was correlated to the shelf‐life stability of the styrene Pickering miniemulsions and the particle size distribution (PSD). Interfacial tension values of aqueous dispersions of SNP‐OSA (DS = 0.11) and SNP‐DSA (DS = 0.14) against toluene as low as 14.7 and 11.0 mN/m, respectively, were observed. Average styrene droplet diameters in the miniemulsions (DV(sty)) ranged between 100–600 nm. 2,2′‐Azobisisobutyronitrile (AIBN) and lauroyl peroxide (LPO) were employed as initiators and the effect of the water solubility on the resulting PSD and latex stability was investigated. The resulting polystyrene (PS) latex particles ranged between 70 and 550 nm in diameter. When AIBN was used as initiator, secondary nucleation was observed. The rate of polymerization and conversion of SNP‐OSA and SNP‐DSA stabilized Pickering miniemulsion polymerizations were compared. The SNP‐armoured PS particles were visualized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). At low conversions (<40%), the resulting latexes were relatively uniform when modified SNP were used as PE along with small amounts of hexadecane as a hydrophobe. At higher conversion, however, coagulation occurred which was correlated to a side reaction in which the PS particles grafted together to form large coagulates.

Nitroxide-mediated polymerization (NMP) is employed to graft synthetic polymers from polysaccharides. This work demonstrates the first successful polymer grafting from starch nanoparticles (SNPs) via NMP. To graft synthetic polymers from the SNPs' surface, the SNPs are first functionalized with 4-vinylbenzyl chloride prior to reaction with BlocBuilder MA yielding a macroinitiator. Methyl methacrylate with styrene, acrylic acid, or methyl acrylate are then grafted from the SNPs. The polymerizations exhibited linear reaction kinetics, indicating that they are well controlled. Thermal gravimetric analysis and spectroscopic techniques confirmed the synthesis of the precursors materials and the success of the grafting from polymerizations. The incorporation of hydrophobic synthetic polymers on hydrophilic SNPs yields new hybrid materials that could find use in several industrial applications including paper coatings, adhesives, and paints.

In this paper, we present the first truly 2-D recognition system of Arabic handwritten words. The used recognizer is the NSHPZ-HMM model with a new zoning design approach. The zoning method we propose depends on the baseline of the treated word. The key point relies in the ability of our baseline to perfectly follow the writing curve even in case of vertical ligatures and of different slant angles within the same Arabic word. The result is an appropriate division in zones of an image word that facilitates its modelization through the use of the NSHPZ-HMM model. Experiments on Arabic literal amounts of AHDB database show the efficiency of the proposed recognition system over an NSHPZ-HMM using zoning independent baseline, a classical pixel-based NSHP-HMM and a set of state of the art systems developed on the same database.

エコシンセティックス社は2006年に製紙用のバイオラテックス「Ecosphere®」を発表した。バイオラテックスは高い接着強度をもち，また独特なレオロジー特性，塗工適性，光学特性に優れている。「水に膨潤し変形可能な内部架橋したナノ粒子で構成されている」という研究成果よりバイオラテックスのユニークな挙動メカニズムが提案されている。バイオラテックスは，石化系バインダーに対して技術的な競争力をもち，代替ができるバインダーである。洋紙・板紙分野において，バイオラテックスを塗工カラーに処方した場合，SBラテックスやSAラテックスの20―50％を等量置換することが可能である。本報文ではエコシンセティックス社の製品開発の展望を紹介し，バイオラテックスに斬新な機能をもたせ，性能を向上させるための品質改良における研究事例を振り返る。この新しいアプローチにより，特にオフセット印刷用の下塗り，上塗りカラーにおける石化系ラテックスの置換を高い割合で出来るようになり，性能向上及びコスト削減が期待されている。