Changes in kernel properties,in situ gelatinization,and physicochemical properties of waxy rice with inhibition of starch branching enzyme during cooking

The kernel properties, gelatinisation and physicochemical properties of rice were investigated in a waxy rice Guang-ling-xiang-nuo (GLXN) and its transgenic line GLXN-RNAi with inhibition of starch branching enzyme I/IIb. The volume swelling, water content and leached material of cooked kernels increased with increasing cooking time, but they were lower in GLXN-RNAi than in GLXN. The kernels of GLXN-RNAi were more difficultly gelatinised and disrupted than those of GLXN during cooking. The starch in the exterior of GLXN-RNAi endosperm was not completely gelatinised. The C_A-type starch of GLXN-RNAi was more resistant to cooking than A-type starch of GLXN. The cooked kernels of GLXN-RNAi had lower rapidly digestible starch and greater slowly digestible starch than those of GLXN. Brown rice flour had higher peak, hot, final and setback viscosities and lower breakdown viscosity in GLXN than GLXN-RNAi. These results indicated that GLXN-RNAi kernels exhibited great potential in applications as health foods.     

A novel nonmetal intercalated high crystalline g-C3N4 photocatalyst for efficiency enhanced H2 evolution

Introducing nickel foam as assistant, a novel nonmetal intercalated high crystalline graphitic carbon nitride (g-C₃N₄) catalyst was successfully fabricated by β-cyclodextrin (β-CD) pretreated melamine with one step thermal polymerization process. The final results show that 0.3-NCCN presented a remarkably visible-light (λ > 400 nm) photocatalytic H₂ evolution reaching 9297  μmol g^?1 h^?1, and the reaction process follows the zero-order kinetic model. The increase in crystallization of 0.3-NCCN implies a higher-ordered arrangement of tris-s-triazine. The nonmetal interlayer formed by oxygen-contained graphitized carbon can extend the π-conjugated system. Both above significantly benefit the rapid migration and separation of charge-carrier. Moreover, the narrowed band gap provides a stronger thermodynamic driving force for improving the photocatalytic water splitting efficiency. Our work paved a new method to construct high performance photocatalyst for water splitting.     

Polylactide latex/nanofibrillated cellulose bionanocomposites of high nanofibrillated cellulose content and nanopaper network structure prepared by a papermaking route

Previous attempts to use polylactide (PLA) latex particles and nanofibrillated cellulose (NFC) in papermaking processing have been limited to low NFC content. In the present study, a bionanocomposite material was successfully produced using a PLA latex and NFC. The components were mixed using a wet mixing method and bionanocomposite films were made by filtration followed by hot pressing. In composite materials, the dispersion of the reinforcing component in the matrix is critical for the material properties. Biopolymers such as PLA are non-polar and soluble only in organic solvents; NFC is, however, highly hydrophilic. By utilizing latex, i.e., an aqueous dispersion of biopolymer micro-particles, wet mixing is possible and the problem of aggregation of the hydrophilic nanocellulose in organic solvent is avoided. The properties of the resulting NFC/PLA latex bionanocomposite films were analyzed. Thorough blending resulted in good dispersion of the reinforcing component within the matrix. Adding increasing amounts of NFC improved the Young's modulus, tensile strength, and strain at break of the bionanocomposite material. The increase in the tensile properties was linear with increasing NFC content as a result of the good dispersion. The NFC also improved the thermal stability of the bionanocomposite material. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

GIS用环氧树脂的增韧改性研究

制备了一种聚氨酯型热致性液晶聚合物,采用液晶增韧改性环氧树脂,分析液晶的含量对环氧树脂力学性能和耐热性的影响。在环氧树脂中同时添加液晶和Al2O3制备了三元共混体系,并对共混体系的力学性能和电性能进行分析。结果表明:当液晶与环氧的质量比为3∶100时,复合材料的冲击强度相对于纯环氧树脂体系提高了60%,拉伸强度和弯曲强度也分别提高了80%和87%,而且液晶的加入对环氧的耐热性基本没影响。在室温下,三元体系的介电常数是二元体系介电常数的1.5倍。     

聚甲醛纤维的制备与性能

采用熔融纺丝方法,通过调整纺丝工艺参数中的卷绕速度及后牵伸倍数,制备了不同工艺下的聚甲醛(POM)纤维;通过对热性能、取向度和力学性能的测试,分析了POM树脂结晶和降解等热学性能对纺丝过程的影响,同时研究了纺丝工艺参数对POM纤维性能的影响;最后对POM纤维的耐酸碱性能进行了研究。结果表明:POM纤维最佳的纺丝速度为490 m/min,牵伸倍数为7.4。POM纤维的耐碱及耐弱酸性好。     

剪切速率对动态硫化PP/EPDM热塑性弹性体相态结构及性能的影响

采用动态硫化法,在双螺杆挤出机中制备以聚丙烯(PP)/三元乙丙橡胶(EPDM)为基体材料的热塑性弹性体,研究螺杆转速对PP/EPDM热塑性弹性体相态结构及性能的影响;采用差示扫描量热(DSC)仪分析了PP/EPDM热塑性弹性体的结晶性能,通过扫描电子显微镜(SEM)分析PP/EPDM热塑性弹性体的微观相态结构,并用万能试验机等对其力学性能进行测试。结果表明,随着螺杆转速的增加,PP/EPDM热塑性弹性体的结晶温度降低,凝胶含量、拉伸强度和断裂伸长率先增大后减小,压缩永久变形先减小后增大,而螺杆转速对硬度的影响不明显。当螺杆转速为180 r/min时,PP/EPDM热塑性弹性体的凝胶含量、拉伸强度和断裂伸长率均达到最大值,分别为56.8%,15.9 MPa和634%,压缩永久变形和硬度(邵A)均达到最小值,分别为68.8%,88。     

Reinforcement of polypropylene with lignocellulose nanofibrils and compatibilization with biobased polymers

Freeze‐dried and milled lignocellulose nanofibrils (LCNF) were used to reinforce polypropylene (PP) nanocomposites. The LCNF, containing up to 9% lignin, was obtained from residual Empty Palm Fruit Bunch (EPFB) fibers. Soy protein isolate (SPI) and hydroxypropyl cellulose (HPC) were tested as coupling agents as well as maleic anhydride grafted polypropylene (MAPP), which was used as a reference. A good level of dispersion of LCNF in the PP matrix while mechanical testing and thermal analyses indicated an improvement of the thermo‐mechanical behavior of the nanocomposites was revealed upon loading of the lignin‐containing nanofibrils. The tensile modulus of PP was increased by 15% upon the addition of 1% LCNF with SPI as a compatibilizer. Likewise, the thermal stability of the composites was most markedly enhanced. Overall, LCNF and SPI, two important bioresources, are introduced here for the development of novel and cost‐effective PP‐based composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43854.