羧甲基淀粉与十六烷基三甲基溴化铵的相互作用研究

通过电导法、粒度法、光谱及热分析等方法研究了羧甲基淀粉与十六烷基三甲基溴化铵之间的相互作用。结果表明,在较低表面活性剂浓度下,静电作用使得羧甲基淀粉与十六烷基三甲基溴化铵发生复合,这一浓度比单一表面活性剂的临界胶束浓度（cmc）低1个数量级;但随表面活性剂的增加,复合物溶液经历澄清-混浊-澄清过程,说明表面活性剂起到了...     

Functionalized expanded corn starch-anchored Cu(I): An efficient and recyclable catalyst for oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

The development of new strategies for the synthesis of biomass-based non-precious metal heterogeneous catalysts has recently received great interest from chemists because of the advantages of these catalytic systems being sustainable, low cost and green. An expanded corn starch-supported CuBr catalyst (ECS-SB-CuBr) has been successfully prepared and well characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectroscopy. Further, ECS-SB-CuBr was used as a heterogeneous catalyst for the selective oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF) and a full HMF conversion is obtained with 98% DFF yield in acetonitrile under ambient pressure of dioxygen at 50°C. The catalyst also showed good reusability, could be easily recovered through filtration and washing and was reused in at least six consecutive runs with virtually no loss of catalytic performance.     

Sustainable chitosan/starch composite material for stabilization of palladium nanoparticles: Synthesis,characterization and investigation of catalytic behaviour of Pd@chitosan/starch nanocomposite in Suzuki–Miyaura reaction

We fabricated a green chitosan/starch composite as support material for stabilization of palladium nanoparticles for the first time. The chemical structure of the sustainable palladium nanocomposite was investigated using various techniques. Characterization studies showed that the average dimensions of the palladium nanocomposite ranged between 16 and 21 nm. The synthesized palladium nanocomposite was employed in the synthesis of a series of biphenyl compounds via Suzuki–Miyaura cross‐coupling reactions with an unconventional technique. All coupling reactions were conducted in very short reaction time and excellent biphenyl yields were obtained in the presence of the nanocomposite. The palladium catalyst was tolerant to a wide range of functional groups. We also investigated the recyclability and reusability of the palladium nanocomposite, and found that it could be used for seven successive cycles.     

A complete TSDC description of molecular mobilities in polylactide/starch blends from local to normal modes: Effect of composition,moisture, and crystallinity

Thermally stimulated depolarization current is applied to study the dielectric relaxations coexisting from 80 to 380 K in the PLLA/starch, immiscible biodegradable blend system. The relaxation parameters are determined for chain mobilities at different ranges, whether in the amorphous or cold‐crystallized state for PLLA, and totally amorphous one for starch as demonstrated by wide‐angle X‐ray scattering experiments. The PLLA crystallization is favored by the presence of starch, in both the crystallinity degree reached and the crystallization time. The effect of moisture is followed for both the local modes and the segmental mobilities, where a bimodal relaxation for starch sweeps the temperature range, thus evidencing the heterogeneities existing in the starch disordered phase. The moisture plasticization effect is estimated and shows differences in the water absorption in starch either neat or as a minority component. The onset of the segmental mobility in PLLA is independent of composition or crystallinity, but the large intensity decrease observed when PLLA cold‐crystallizes evidences the simultaneous formation of a rigid amorphous fraction and the crystallites. The normal relaxation mode is recorded in amorphous PLLA whether neat or blended, which again demonstrates the absence of interactions among the blend components. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 680–691     

Thermoplastic starch and glutaraldehyde modified thermoplastic starch foams prepared using supercritical carbon dioxide fluid as a blowing agent

Supercritical carbon dioxide (scCO₂) processed thermoplastic starch (scCO₂^aTPS), cellulose nanofiber (CNF) modified scCO₂^aTPS (scCO₂^aTPS₁₀₀CNF_0.02) and glutaraldehyde (GA) modified scCO₂^aTPS₁₀₀CNF_0.02 (scCO₂^aTPS₁₀₀CNF_0.02GA_x) foams were prepared for the first time using scCO₂ as a blowing agent during their foaming processes. The expansion ratio, cell density, moisture resistance, and compressive strength (σ_c) retention properties of each foam series were considerably improved with increasing scCO₂ pressure during the foaming processes. The expansion ratios and cell densities of each scCO₂^aTPS₁₀₀CNF_0.02GA_x foam series were increased considerably to a maximum value, as the GA content approached an optimum value. The optimal scCO₂¹¹TPS₁₀₀CNF_0.02GA_1.6 foam material exhibited a high expansion ratio and cell density at approximately 50 and approximately 8 × 10⁸ cells/cm³, respectively. Compared with corresponding aged scCO₂^aTPS and scCO₂^aTPS₁₀₀CNF_0.02 foam specimens, considerably better moisture resistance and σ_c retention properties were observed for scCO₂^aTPS₁₀₀CNF_0.02GA_x foam specimens, when they were modified with the corresponding optimum GA content. The moisture resistance and σ_c retention for optimal prepared scCO₂⁷TPS₁₀₀CNF_0.02GA_0.4, scCO₂⁹TPS₁₀₀CNF_0.02GA_0.8 and scCO₂¹¹TPS₁₀₀CNF_0.02GA_1.6 foam materials improved further with increasing scCO₂ pressure. Possible reasons accounting for the highly expansion ratio, moisture resistance, and σ_c retention properties for scCO₂^aTPS₁₀₀CNF_0.02GA_x foams are presented.     

Characterization of gluten-free bread crumb baked at atmospheric and reduced pressures using TD-NMR

This research aimed to study the effects of using a partial vacuum for bread baking on macromolecules and water distribution in gluten-free bread. Bread baking under partial vacuum results in greater oven rise and a larger gas fraction in the crumb. Because water's boiling point decreases under reduced pressure, it was expected that its distribution within the dough and its interactions with the others dough's constituents (mainly starch) would differ from those in bread baked under atmospheric pressure. Time-domain nuclear magnetic resonance was used, as it has the rare capacity to quantify both gelatinization and retrogradation of starch. Complementary rheological measurements made it possible to show that crumb Young's modulus was mostly influenced by the gas fraction whereas there was little change in starch gelatinization and retrogradation when dough was baked under partial vacuum. When insufficiently hydrated (48%), the volume of breads was practically the same whatever the baking process. Meanwhile, the nuclear magnetic resonance results suggested that amylose short-term crystallization (on cooling) is dependent on water content. In addition, crumb Young's modulus during storage at room temperature correlated with an increase in free induction decay signal intensity.     

醋酸淀粉酯浆料的研制

对醋酸淀粉酯的变性工艺进行了系统的研究和探讨,以浆纱性能为依据,确定了次氯酸钠氧化预处理工艺和醋酸乙烯酯乙酰化工艺的最佳反应条件,进一步提高了醋酸淀粉酯浆料的性能,扩大了醋酸淀粉酯在纺织经纱上浆中的应用.     

压力对淀粉酶解程度的影响

研究了经高压(100～450MPa)处理后的淀粉对酶水解的敏感性.结果表明:高压处理对淀粉的酶解程度影响不大.     

藕淀粉特性的研究

就藕根茎淀粉的分子结构形状及其理化特性进行了研究。结果表明碘亲和力测定的藕直链淀粉含量为15．9％,蓝色值法为17．4％,开始凝胶化温度为58．5℃,淀粉颗粒与木薯淀粉、大米淀粉等有类似的性质,可作为此类淀粉制品的替代品。     

粉葛淀粉的理化特性

粉葛淀粉的理化特性;葛淀粉;糊化特性;X射线衍射;流变