壳聚糖改性及用其整理纺织品抗菌性能的研究

用羟甲基化和醚化等方法制备了改性壳聚糖羟甲基壳聚糖和羟乙基乙基醚壳聚糖。在中性条件下它们溶解于水。实验显示，改性壳聚糖具有较好的抑菌作用和吸湿保湿性能。对织物进行的后整理实验发现，羟乙基乙基醚壳聚糖适用于对棉布的整理加工，羟甲基壳聚糖适用于对真丝绸的整理加工。经整理后的织物具有较好的抗菌性，且吸湿、透湿、染色性能较优。研究表明改性壳聚糖可作为优良的功能性天然“绿色”纺织品整理剂。     

超分子组装在二维材料基室温甲醛传感材料中的应用

甲醛作为室内空气中的主要挥发性有机化合物之一,对人体的健康产生了极大的威胁,因此对甲醛进行检测具有重要意义.传统的电阻式气体传感器一般基于低成本和高灵敏的金属氧化物,但其较高的操作温度和较低的选择性限制了它们的实际应用.开发高性能室温甲醛传感器迫在眉睫,其核心则是寻找性能优异的室温甲醛传感材料.二维材料由于具有独特的物理化学性质和电学性能,成为高性能室温甲醛传感器的热门候选材料.另一方面,超分子组装作为一种温和的材料修饰改性策略,也为大幅提高二维材料的室温甲醛传感性能提供了可能.本文整理了近年来基于二维材料的室温甲醛传感相关工作,总结了甲醛气体分子的传感机制,梳理了二维材料的分类与特性,归纳了用于室温甲醛传感的基于二维材料“主体”的超分子组装策略,并着重介绍了二维材料基超分子组装材料在电阻式室温甲醛传感中的应用,并对二维材料基室温甲醛传感材料的未来发展进行了展望.     

草酸改性空气凤梨生物炭吸附甲醛的机理研究

探究草酸改性园林废弃物类生物炭对溶液中甲醛的吸附效率和固定的机理,为园林废弃物类生物炭在甲醛污染控制方面的应用提供科学依据.利用马弗炉在低氧条件下将空气凤梨原材料和草酸改性后的原材料制备成生物炭.然后利用实验室模拟法,研究不同反应时间、甲醛浓度、pH对生物炭吸附效果的影响,并分析草酸改性如何提高园林废弃物类生物炭对甲醛...     

改性高分子超滤膜的研究进展

随着超滤膜技术的发展,人们对膜材料的性能不断提出新的要求,其中改善膜的亲水性,提高膜的抗污染能力已成为有待解决的迫切问题.由于单一的膜材料很难同时具有良好的亲水性、成膜性、热稳定性、化学稳定性、耐酸碱性、耐微生物性侵蚀、耐氧化性和较好的机械强度等优点,因此采用膜材料改性或膜表面改性的方法来提高膜的性能,是解决这一问题的关键.本文介绍了目前国内外高分子超滤膜材料改性中常用的化学改性和物理改性方法.其中,化学改性可以通过膜材料和膜表面的化学改性来实现;而物理改性则主要是通过材料改性来实现.     

漫反射光谱评价不同环境因素对栀子染色真丝织物的老化影响

采用漫反射光谱评价了不同环境因素对栀子染色真丝织物老化的变色规律和速度。结果表明:365nm光辐照和100℃条件对栀子染色织物的影响较大,并且光谱随老化时间增长呈渐变趋势;就室内常见污染气体乙酸、甲醛而言,乙酸气体对栀子染色真丝织物有较大损害,甲醛气体对栀子染色真丝织物影响较小。     

不同有机分子改性羟基磷灰石用于甲醛催化氧化

分别采用十六烷基三甲基溴化铵(CTAB)、十二烷基硫酸钠(SDS)及柠檬酸钠(SC)对羟基磷灰石(HAP)进行了有机改性.柠檬酸钠改性的羟基磷灰石对甲醛催化氧化表现出最好的催化活性,在240℃实现了甲醛完全转化.通过X射线衍射、红外光谱、N2吸附-脱附、扫描电镜和热重/差重等手段对HAP结构进行了表征.结果表明,SC改性使得HAP比表面积和孔体积增加,孔径减小,更有利于吸附及传质,从而提高了其活性.此外,SC改性的HAP中羟基含量更多,更有利于甲醛与羟基之间发生相互作用,这是该样品活性提高的另一个原因.     

道路反光标志带用玻璃微珠的表面化学修饰

道路反光标志带用的反光材料--玻璃微珠的反光性是人们关注的研究课题.国内外对玻璃微珠表面曾采用"真空镀铝"[1]、"NDI-301(或302)偶联剂"[2]进行改性.前者虽可提高玻璃微珠的反光性,但操作繁琐和成本高,后者只能提高玻璃微珠对树脂层的亲合力和粘接强度,反光性未获改善;并且两者均不能赋予发光性.鉴此,以铝-钛偶联剂、BCP-1170荧光粉及辅剂等化学修饰玻璃微珠表面,镀上光亮的铝-钛反光膜、发光膜,既提高了玻璃微珠的反光性,同时赋予发光性.     

谷朊蛋白的改性及其作为纸张增强剂的性能

采用廉价可生物降解的小麦谷朊蛋白为原料,经过羟甲基化和阳离子化改性合成类似聚酰胺聚胺环氧氯丙烷(PPE)的纸张增强剂. 经改性后,谷朊蛋白带有氮杂环丁烷结构、表氯醇和环氧基团3种功能基团,可与纤维形成共价键,且能发生自身交联,在纤维周围形成三维交联网络结构,提高纸张干、湿强度. 通过单因素试验,研究了甲醛、甲酸、温度、反应时间和环氧氯丙烷5种反应因素对纸张强度的影响. 优化合成条件下制备改性谷朊蛋白可使纸张干抗张强度提高35%,湿强保留率达20%. 改性后谷朊蛋白显阳离子性,加入纸浆中,可使得浆料体系Zeta电位升高,改善浆料的留着率,明显提高纸张强度. 结果表明,经羟甲基化和环氧氯丙烷加成改性的谷朊蛋白可以作为纸张的干强剂和湿强剂.     

改性聚乙烯醇低温耐水纸制品粘合剂的研制

以盐酸为催化剂,通过甲醛与聚乙烯醇(PVA)反应制得聚乙烯醇缩甲醛(PVF);用三聚氰胺、尿素进行交联,形成尿素-三聚氰胺-甲醛树脂PVFA;然后再分别用乙二醛、氮丙啶进行一步交联得PVFB、PVFC.讨论了不同交联剂的用量和温度对改性PVF的黏度和耐水性的影响.结果表明,当三聚氰胺、尿素、乙二醛及氮丙啶的用量分别为3%、8%、2%及0.2%时制备的交联改性PVA粘合剂达到最佳耐水效果,又能满足低温纸制品生产线要求.     

ZSM—5担载铱催化1—己烯氢甲酰化Ⅱ.催化剂选择性及动力学

采用离子交换法制得的rZSM-5催化剂在催化1－己烯氢甲酰化反应中，副反应己烯加氢生成正己烷较多。用三苯基膦和甲醛在CO／H2反应气中对催化剂进行改性，产物醛的选择性显著提高。CO、H2吸附研究结果表明，改性使催化剂对H2的不可逆吸附及Vco/VH2比降低，而使其对CO的吸附变得完全可逆。反应动力研究表明，总压对改性后催化的活必, 明显影响，但产物醛的正／异比按总压升高而降低。CO分压升高有利于醛的生成和正／异比的提高。提高反应温度和选择性，正／异比降低。通过非线性回归分析，建立速率方程如下：r=kC^0.9 C6 P^0.99H2P^-1.5CO活化能E＝43.1kJ/mol.     

MODIFICATION OF SILK FIBER via EMULSION GRAFT COPOLYMERIZATION WITH FLUOROACRYLATE

2,2,3,3,4,4,5,5-Octafluoropentyl acrylate was grafted onto silk fiber in a two-step heterogeneous system through the vinyl bonds of acryloyloxyethyl isocyanate modified on the silk.The grafted copolylner was analyzed by FTIR and WAXD,and the results revealed that the fluoroacrylate was successfully grafted onto silk fiber and the crystalline structure of silk fibroin withβ-sheet structure was not changed after graft copolymerization.The FT-IR corrected method was used to simulate the grafting yield onto ...     

聚β-羟基丁酸酯辐照接枝顺丁烯二酸酐及产物表征

探索了一种提高聚β羟基丁酸酯(PHB)热稳定性的方法,即用60Coγ射线辐照对PHB进行顺丁烯二酸酐(MAH)的接枝,采用1HNMR、13CNMR、TGA、DSC、XRD等方法对辐照接枝产物进行了表征.1HNMR、13CNMR谱图结果表明MAH单体接枝到了PHB上.TGA测试表明,辐照接枝产物的热稳定性显著提高,如接枝率为0.52%的样品热分解温度提高了36K.DSC研究表明辐照接枝产物的熔融温度和结晶温度均降低.此外,由于引入极性单体顺丁烯二酸酐,接枝产物的结晶度降低,同时亲水性提高.     

Silkworm silk/poly(lactic acid) biocomposites: Dynamic mechanical, thermal and biodegradable properties

Silkworm silk/Poly(lactic acid) (silk/PLA) biocomposites with potential for environmental engineering applications were prepared by using melting compound methods. By means of Dynamic mechanical analysis (DMA), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Coefficient of thermal expansion test, Enzymatic degradation test and Scanning electron microscopy (SEM), the effect of silk fiber on the structural, thermal and dynamic mechanical properties and enzymatic degradation behavior of the PLA matrix was investigated. As silk fiber was incorporated into PLA matrix, the stiffness of the PLA matrix at higher temperature (70-160 °C) was remarkably enhanced and the dimension stability also was improved, but its thermal stability became poorer. Moreover, the presence of silk fibers also significantly enhanced the enzymatic degradation ability of the PLA matrix. The higher the silk fiber content, the more the weight loss.     

Crystallization behavior, thermal property and biodegradation of poly(3-hydroxybutyrate)/poly(ethylene glycol) grafting copolymer

The poly(3-hydroxybutyrate)(PHB)/poly(ethylene glycol)(PEG) grafting copolymer was successfully prepared by PHB and acrylate groups ended PEGM using AIBN as initiator. The crystallization behavior, thermal stability and environmental biodegradability of PHB/PEG grafting copolymers were investigated with differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), and Biodegradation test in vitro. In the results, all the grafting copolymers were found to show the X-ray diffraction arising from the PHB crystal lattice, while none of the PEG crystallized peaks could be found even though the graft percent reached 20%. This result indicated that PEG molecules were randomly grafted onto PHB chain. The thermal properties measured by DSC showed that the melting temperature(T_m) and glass transition temperature (T_g) were both shifted to lower temperature with the graft percent increasing, and this broadened the narrow processability window of PHB. According to TGA results, the thermal stability of the grafting copolymers is not changed compared to pure PHB. From the biodegradation test, it could be concluded that degradation occurred gradually from the surface to the inside and that the degradation rate could be adjusted by the PEG grafting ratio. In another words, the biodegradation profiles of PHB/PEG grafting copolymer can be controlled. These properties make PHB/PEG grafting copolymer have promising potential applications especially in agriculture fields.     

Graft copolymerization of itaconic acid-methacrylamide comonomers onto poly(ethylene terephthalate) fibers

The graft copolymerization of itaconic acid-methacrylamide (IA-MAAm) comonomers was carried out using benzoyl peroxide as initiator onto poly(ethylene terephthalate) (PET) fibers in an aqueous medium. The grafted fibers were characterized by FTIR, TGA, DSC and SEM analysis. Effect of various parameters on graft yield such as feed composition, feed and initiator concentration, reaction time and temperature were investigated. The graft yield in the presence of MAAm increased because of the synergistic effect of MAAm comonomer. While, the graft yield alone with the IA onto PET fiber was 2.2%, the use of MAAm as a comonomer increased the amount of IA introduced to the PET fiber up to 13.7%. The reactivity ratios for both monomers were determined by using a Fineman-Ross plot. The grafting rate and saturation graft yield was increased upon increasing the temperature between 65 °C and 85 °C. When the temperature increased further than 85 °C, the saturation graft yield decreased. The graft yield has shown an increase up to an initiator concentration of 1.0 × 10⁻² M and slightly decreased. The grafting increased the dyeability with acidic and basic dyes, and moisture absorption capacity but decreased the thermal stability of the fibers.     

Characterization and Studies on Grafting of Methyl Methacrylate onto PAN Fibers

The graft copolymerization of methyl methacrylate (MMA) onto commercial acrylic fibers (PAN) has been studied using Azobis(isobutyro)nitrile (AIBN) as an initiator. MMA grafting initiated by radicals formed from thermal decomposition of AIBN. In this study, the effects of monomer and initiator concentration, time and temperature reaction on the grafting yield have been investigated.

The optimum conditions for this grafting reaction were obtained with an MMA concentration of 0.7 M, an AIBN concentration of 0.0073 M, a reaction temperature of T=85°C and with a 60 min reaction time.

The fiber structure has been investigated by different experimental techniques of characterization such as Fourier transform infrared spectroscopy (FT‐IR), calorimetric analysis (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), water absorption and the physical and mechanical properties has also been investigated in this study. The thermal analysis data showed that by increasing grafting yield, little changes have occurred in fibers samples up to 13.5% of grafting yield and the thermal transitions of grafted fibers have approximately the same behavior compared with the raw fibers sample. Grafting also slightly affected the fiber morphology. The experimental data of mechanical properties clearly show that by increasing grafting yield, max extension will decrease but this change up to 13.5% grafting yield is barely noticeable. Grafting of poly MMA improved water absorption.     

一缩二乙二醇二甲基丙烯酸酯接枝真丝的结构

通过电子扫描电镜 (SEM)、红外光谱 (IR)、双折射、X 射线衍射及氨基酸分析等手段 ,研究了真丝用一缩二乙二醇二甲基丙烯酸酯 (P 2 )接枝后其结构与接枝率之间的关系 .氨基酸分析结果表明P 2接枝主要在真丝大分子中酪氨酸、丝氨酸、组氨酸和精氨酸的NH2 、OH和—NH—活性基团上 .通过X 射线衍射分析 ,P 2接枝并不直接影响结晶区 ,但引起分子取向的下降 ,接枝后真丝双折射下降说明接枝后因大分子取向度下降 ,接枝真丝的红外光谱显示出真丝具有 β折迭结构和P 2高聚物的结构特征峰 ,从而说明P 2接枝在纤维的无定型区内部进行 .当接枝率大于 35 %时 ,纤维的表面覆盖了一层高聚物 (P 2 ) ,并且纤维的横截面表现出明显的分纤现象 ,接枝真丝的红外光谱表明了纤维与P 2重叠吸收峰 ,说明了P 2在丝纤维内部接枝聚合 .     

蚕丝辐射接枝丙烯腈

以氯化锌水溶液为溶剂 ,用钴 60γ射线引发蚕丝均相溶液接枝丙烯腈 .研究了辐射吸收剂量、剂量率、铜离子浓度、蚕丝浓度和单体浓度及“后效应”对单体转化率、接枝率、接枝效率、接枝链分子量的影响 ;研究发现初始接枝效率主要取决于 [S]丝/ ( [S]丝 +[M]单) ,接枝效率随吸收剂量增加而增加 ;铜离子的存在使接枝链分子量下降 ,而对接枝率和接枝效率影响不大 ;用IR、TGA、DTA等多种方法对接枝物进行了表征 ,表明蚕丝接枝上聚丙烯腈后 ,其热学性能有较大提高 .     

聚β-羟基丁酸酯顺丁烯二酸酐接枝共聚物的研究

采用DSC、TGA、POM和WAXD等方法对聚 β 羟基丁酸酯 (PHB)及其接枝顺丁烯二酸酐共聚物 (PHB g MA)的结晶行为、热稳定性和生物降解特性进行了研究 .结果表明接枝产物的热稳定性明显优于PHB ,热分解温度提高了 2 0余度 ;结晶行为发生很大的变化 .结晶速率减小 ,结晶温度降低 ,冷结晶温度升高 ,球晶的织态结构也随着MA接枝量的变化发生明显变化 ,并且接枝MA促进了PHB的生物降解     

Comparison of different methods for determining the imidization degree of polyimide fibers

In this study, polyimide fibers at different stages of imidization were characterized by TGA, DSC, and FTIR. The imidization degree(ID) calculated by TGA was based on the weight loss of each sample, which was caused by the imidization of residual amic acid groups. The results of TGA showed good regularity with the thermal treatment temperature of the PI fibers. For DSC, the ID was calculated based on the area of endothermal peak of each sample. Compared with TGA, DSC showed a relatively higher value because the endothermal peak was reduced by the exothermic re-formation of polyamic acid which may be partially degraded during thermal treatment. The IDs obtained by the FTIR spectra generally showed poorer regularities than those obtained by both TGA and DSC, especially for the results calculated using the 730 cm-1 band. Based on the 1350 cm-1 band, the obtained IDs showed better agreement with the TGA or DSC results. The results obtained by these three methods were compared and analyzed. The ID obtained by TGA showed much more reliability among these three methods.