交联淀粉微球的阳离子化改性研究

以3-氯-2-羟丙基三甲基氯化铵GTA为醚化剂与交联淀粉微球CSMs反应制备阳离子淀粉微球,探讨影响取代度和反应效率的因素,用FT-IR、SEM、XRD、DSC对产物进行表征。阳离子淀粉微球保持了CSMs的圆整形态,但粒径略有增大,分散性能更好。醚化反应进一步破坏了淀粉分子间的氢键作用,阳离子淀粉微球结晶度更加降低,孔隙度变得更大。     

高取代度阳离子糯玉米淀粉的制备及脱色性能研究

本文以糯玉米淀粉为原料,乙醇水溶液为溶剂,3-氯-2-羟丙基三甲基氯化铵为阳离子醚化剂,氢氧化钠为催化剂,对高取代阳离子糯玉米淀粉的制备工艺及脱色性能进行了研究。考察了醚化剂用量、pH值、乙醇用量、反应温度、反应时间对阳离子糯玉米淀粉取代度和反应效率的影响。结果表明：醚化剂用量、pH值、乙醇用量、反应温度、反应时间对糯玉米淀粉的阳离子化反应均有影响。阳离子糯玉米淀粉的较佳制备条件为：醚化剂与糯玉米淀粉（干基）摩尔比0.5,pH值10.5,乙醇与糯玉米淀粉（干基）摩尔比4.0,反应温度50℃,反应时间12h。对阳离子糯玉米淀粉脱色性能研究结果表明：阳离子糯玉米淀粉对甲基橙有优异的脱色效果。当其投加量为140mg/L时,对质量浓度为50mg/L甲基橙脱色率可达73%。     

半干法制备阳离子淀粉的工艺优化

以玉米淀粉为原料,3-氯-2-羟丙基三甲基氯化铵(CTA)为醚化剂,在碱性条件下,采用半干法制备低取代度阳离子淀粉。采用Box-Behnken中心组合响应面设计,对半干法工艺进行优化,并分析反应温度、反应时间、碱的用量、体系含水量对阳离子淀粉取代度的影响。结果表明:回归方程能较好地预测取代度随工艺条件变化的规律,半干法制备低取代度阳离子淀粉工艺条件为:反应温度64.40℃,反应时间6.58 h,NaOH与醚化剂摩尔比2.12,体系含水量25.28%,在此条件下制得的阳离子淀粉取代度为0.051 9。     

一种新型两性淀粉的制备方法

研究了在低温条件下,采用同一醇与水的混合溶剂使淀粉与3-氯-2-羟丙基三甲基氯化铵和氯乙酸进行醚化反应,制得一种新型的两性淀粉.并探讨了反应温度、反应时间以及阳离子醚化剂、阴离子醚化剂用量对其取代度的影响.     

微波干法制取低取代度阳离子淀粉的研究

以玉米淀粉及3-氯-2-羟丙基三甲基氯化铵(CHPTMA)为原料,NaOH为催化剂,采用微波干燥法制取可用于造纸的低取代度季铵型阳离子淀粉.考察了醚化剂用量反应时间和反应温度对取代度的影响,确定了最佳反应配方和反应条件,并对产物进行了性能检测.结果表明:微波法可大大加快醚化反应速率,缩短反应时间.     

阳离子醚化剂的制备及应用

主要研究了阳离子醚化剂3-氯-2-羟丙基三甲基氯化铵(CHPT)的合成工艺条件，探讨了反应温度、盐酸质量分数、溶液pH值、环氧氯丙烷与三甲胺盐酸盐摩尔比对阳离子醚化剂合成的影响，并采用真空恒沸汽提(载气提取)的方法对产物进行提纯。利用该阳离子醚化剂在温度60-70℃，反应4h时，再用乙醇溶液浸泡，过滤、洗涤、真空干燥，制得高取代度阳离子淀粉(取代应为0．5)。将其应用在造纸过程中，可取得较好的助留效果。     

微波辅助干法制备阳离子木薯淀粉

采用微波辅助加热法干法制备阳离子淀粉,详细考察了微波功率、微波辐照时间、氢氧化钠用量和3-氯-2-羟丙基三甲基氯化铵醚化剂（CHPTMA）用量等对反应效率及其产品取代度的影响。结果表明：微波干法合成阳离子淀粉,反应时间短,反应效率高;在NaOH分2次加入、NaOH与淀粉质量比为4.0%、醚化剂用量为淀粉质量的4.5%、水用量为淀粉用量的25.0%、微波功率为450 W及微波辐照时间为3.0 min等条件下,阳离子淀粉取代度为0.037 5,阳离子醚化剂反应效率高达93.76%。     

季铵醚化改性对磷酸酯淀粉浆料性能的影响

为提高磷酸酯淀粉浆料的使用性能,通过改变3-氯-2羟丙基三甲基氯化铵醚化剂对磷酸酯淀粉的投料比,制备了一系列具有不同季铵醚阳离子取代度的磷酸酯变性淀粉。通过性能对比实验,研究了这种变性淀粉的季铵阳离子化变性对浆液ζ电位、黏度以及黏附性能和浆膜性能的影响。结果表明：随着季铵阳离子取代度的增加,这种变性淀粉浆液的ζ电位升高,黏度明显提高;季铵阳离子化变性能够进一步改善磷酸酯淀粉对棉纤维的黏附性能;随着阳离子取代度的增加,对棉纤维的黏附性能增大,浆膜的断裂伸长率增大。     

阳离子香豆素的合成及其对高得率浆的返黄抑制作用

以3-氨基酚和乙酰乙酸乙酯为原料,在Lewis酸的催化下,通过Pechmann法合成了 7-氨基-4-甲基香豆素。将阳离子醚化剂2,3-环氧丙基三甲基氯化铵与7-氨基-4-甲基香豆素反应,实现了7-氨基-4-甲基香豆素的阳离子化。通过红外光谱和核磁共振光谱对合成产物的结构进行表征;采用紫外光谱、荧光光谱探讨了其光学性质;采用紫外光加速老化实验检测了合成产物对纸张返黄的抑制效果。结果表明,该阳离子化的7-氨基-4-甲基香豆素的亲水性较好,能在较长时间内抑制纸张返黄。     

微波法合成阳离子淀粉醚的工艺研究

以玉米淀粉及3-氯-2-羟丙基三甲基氯化铵(CTA)为原料,采用微波辐射法制备了低取代度季铵盐型阳离子淀粉醚,研究了醚化剂用量、碱用量、微波功率及反应时间等因素对合成的影响。确定最佳合成工艺为:W(淀粉)∶W(CTA)∶W(Na OH)=100∶9∶2,微波功率500 W,反应时间20 min,反应效率为86.5%,所得的产物的取代度为0.0346。     

用含三嗪结构苯基磷酸酯的涤纶织物阻燃整理

为提高涤纶织物的阻燃性能和润湿性能,用2,4-二羟乙基胺-6-氯-1,3,5-三嗪与苯基磷酰二氯制备了含三嗪环的苯基磷酸酯结构的P-N型阻燃整理剂BPAT,并采用二浸二轧整理工艺对涤纶织物进行阻燃整理。通过比较整理前后织物的红外光谱、扫描电子显微镜、热力学数据、续燃和阴燃时间及润湿角,讨论了BPAT整理对涤纶织物阻燃性能的影响。结果表明：BPAT 可提高涤纶织物的残炭率超过3倍,降低织物燃烧的阴燃和续燃时间到0.2s和6.2s,对涤纶织物具有较好的阻燃效果;经10次水洗,整理织物的阻燃性略有降低,但降低程度不大,整理织物具有一定的阻燃耐久性。整理后涤纶织物的润湿性能明显改善。     

高取代度羧甲基小麦淀粉制备工艺的优化及表征

摘 要：以小麦淀粉为原料,以氯乙酸作为醚化剂,采用两次加碱法制备了高取代度的羧甲基小麦淀粉。以4.05g淀粉为基准,采用正交实验对反应条件进行了优化,得到的最佳工艺条件为：水用量6mL,无水乙醇用量60mL,氯乙酸与淀粉摩尔比1.4,氢氧化钠与氯乙酸摩尔比1.8,碱化用氢氧化钠百分比70%,碱化温度35～40℃,碱化时间0.5～1h,醚化温度50～55℃,醚化时间2～3h,在此条件下制得了取代度高达1.21的羧甲基小麦淀粉。     

Biodegradation of RDX nitroso products MNX and TNX by cytochrome P450 XplA

Anaerobic transformation of the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) by microorganisms involves sequential reduction of N-NO(2) to the corresponding N-NO groups resulting in the initial formation of MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine). MNX is further reduced to the dinitroso (DNX) and trinitroso (TNX) derivatives. In this paper, we describe the degradation of MNX and TNX by the unusual cytochrome P450 XplA that mediates metabolism of RDX in Rhodococcus rhodochrous strain 11Y. XplA is known to degrade RDX under aerobic and anaerobic conditions, and, in the present study, was found able to degrade MNX to give similar products distribution including NO(2)(-), NO(3)(-), N(2)O, and HCHO but with varying stoichiometric ratio, that is, 2.06, 0.33, 0.33, 1.18, and 1.52, 0.15, 1.04, 2.06, respectively. In addition, the ring cleavage product 4-nitro-2,4,-diazabutanal (NDAB) and a trace amount of another intermediate with a [M-H](-) at 102 Da, identified as ONNHCH(2)NHCHO (NO-NDAB), were detected mostly under aerobic conditions. Interestingly, degradation of TNX was observed only under anaerobic conditions in the presence of RDX and/or MNX. When we incubated RDX and its nitroso derivatives with XplA, we found that successive replacement of N-NO(2) by N-NO slowed the removal rate of the chemicals with degradation rates in the order RDX > MNX > DNX, suggesting that denitration was mainly responsible for initiating cyclic nitroamines degradation by XplA. This study revealed that XplA preferentially cleaved the N-NO(2) over the N-NO linkages, but could nevertheless degrade all three nitroso derivatives, demonstrating the potential for complete RDX removal in explosives-contaminated sites.     

微波半干法高取代度阳离子木薯淀粉制备及其对AKD的乳化性能

以3-氯-2-羟丙基三甲基氯化铵为醚化剂,采用微波半干法制备了低黏度阳离子氧化木薯淀粉,研究了醚化剂用量、氢氧化钠用量、乙醇用量、反应温度和反应时间对反应的影响,并对产品乳化AKD的性能进行了研究。研究结果表明,最佳反应条件为：醚化剂用量53%、氢氧化钠用量14%、醚化剂与氢氧化钠摩尔比1：1,并用氢氧化钠与乙醇配制成质量分数为8%的溶液,体系含水量为18.5%,反应温度为60℃,反应时间3h,产品取代度达到0.3906,反应效率85.53%。所得产品对AKD具有良好的乳化性能。     

Alkaline hydrolysis of the cyclic nitramine explosives RDX,HMX, and CL-20: new insights into degradation pathways obtained by the observation of novel intermediates

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, I) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) hydrolyze at pH > 10 to form end products including NO2-, HCHO, HCOOH, NH3, and N2O, but little information is available on intermediates, apart from the tentatively identified pentahydro-3,5-dinitro-1,3,5-triazacyclohex-1-ene (II). Despite suggestions that RDX and HMX contaminated groundwater could be economically treated via alkaline hydrolysis, the optimization of such a process requires more detailed knowledge of intermediates and degradation pathways. In this study, we hydrolyzed the monocyclic nitramines RDX, MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine), and HMX in aqueous solution (pH 10-12.3) and found that nitramine removal was accompanied by formation of 1 molar equiv of nitrite and the accumulation of the key ring cleavage product 4-nitro-2,4-diazabutanal (4-NDAB, O2NNHCH2NHCHO). Most of the remaining C and N content of RDX, MNX, and HMX was found in HCHO, N2O, HCOOH, and NH3. Consequently, we selected RDX as a model compound and hydrolyzed it in aqueous acetonitrile solutions (pH 12.3) in the presence and absence of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) to explore other early intermediates in more detail. We observed a transient LC-MS peak with a [M-H] at 192 Da that was tentatively identified as 4,6-dinitro-2,4,6-triaza-hexanal (O2NNHCH2NNO2CH2NHCHO, III) considered as the hydrolyzed product of II. In addition, we detected another novel intermediate with a [M-H] at 148 Da that was tentatively identified as a hydrolyzed product of III, namely, 5-hydroxy-4-nitro-2,4-diaza-pentanal (HOCH2NNO2CH2NHCHO, IV). Both III and IV can act as precursors to 4-NDAB. In the case of the polycyclic nitramine 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), denitration (two NO2-) also led to the formation of HCOOH, NH3, and N2O, but neither HCHO nor 4-NDAB were detected. The results provide strong evidence that initial denitration of cyclic nitramines in water is sufficient to cause ring cleavage followed by spontaneous decomposition to form the final products.     

阳离子淀粉絮凝剂制备及脱色性能研究

以马铃薯淀粉为原料,3～氯-2-羟丙基三甲基氯化铵为醚化剂,干法工艺制备了季铵型阳离子淀粉絮凝剂(DS=0.099),以荧光黄E-8G染料溶液模拟印染废水,研究了染料浓度、絮凝剂用量、脱色时间和废水pH对脱色率和吸附量的影响.结果表明:阳离子淀粉絮凝剂对碱性印染废水有较好的脱色能力;在废水pH为12.5,染料浓度113.5 mg/L,絮凝剂用量120 mg/L,脱色时间2 h条件下,脱色率达63.2%,吸附量为0.612 mg/mg;絮凝剂对酸性染料分子的吸附符合Langmuir单分子层吸附理论.     

Degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) using zerovalent iron nanoparticles

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a common contaminant of soil and water at military facilities. The present study describes degradation of RDX with zerovalent iron nanoparticles (ZVINs) in water in the presence or absence of a stabilizer additive such as carboxymethyl cellulose (CMC) or poly(acrylic acid) (PAA). The rates of RDX degradation in solution followed this order CMC-ZVINs > PAA-ZVINs > ZVINs with k1 values of 0.816 +/- 0.067, 0.082 +/- 0.002, and 0.019 +/- 0.002 min(-1), respectively. The disappearance of RDX was accompanied by the formation of formaldehyde, nitrogen, nitrite, ammonium, nitrous oxide, and hydrazine by the intermediary formation of methylenedinitramine (MEDINA), MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine), DNX (hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine), TNX (hexahydro-1,3,5-trinitroso-1,3,5-triazine). When either of the reduced RDX products (MNX or TNX) was treated with ZVINs we observed nitrite (from MNX only), NO (from TNX only), N2O, NH4+, NH2NH2 and HCHO. In the case of TNX we observed a new key product that we tentatively identified as 1,3-dinitroso-5-hydro-1,3,5-triazacyclo-hexane. However, we were unable to detect the equivalent denitrohydrogenated product of RDX and MNX degradation. Finally, during MNX degradation we detected a new intermediate identified as N-nitroso-methylenenitramine (ONNHCH2NHNO2), the equivalentof methylenedinitramine formed upon denitration of RDX. Experimental evidence gathered thus far suggested that ZVINs degraded RDX and MNX via initial denitration and sequential reduction to the corresponding nitroso derivatives prior to completed decomposition but degraded TNX exclusively via initial cleavage of the N-NO bond(s).     

季铵型淀粉上浆性能的研究

用3-氯-2羟丙基三甲基氯化铵作为淀粉醚化试剂,采用半干法合成工艺制备了一系列不同取代度的季铵型阳离子淀粉,在取代度DS小于0.2的范围内,对其退浆性能、与PVA浆料的混溶性能及上浆性能进行了试验.低取代度的季铵型淀粉容易退浆;与PVA有较好的混溶性;取代度为0.030时对纯棉纱上浆性能优越,对涤棉纱上浆性能可行.