笼形八聚(二甲基硅氧基)倍半硅氧烷的合成与表征

以四乙氧基硅烷〔Si(OEt)4〕与五水合四甲基氢氧化铵(Me4NOH.5H2O)为原料水解缩合得到笼形八聚四甲基铵硅酸盐([SiO1.5ONMe4]8),继而与二甲基氯硅烷〔HSi(CH3)2Cl〕反应,一锅法合成了笼形八聚(二甲基硅氧基)倍半硅氧烷(Q8M8H),最佳反应条件为:反应温度25℃,反应时间36 h,n〔Si(OEt)4〕∶n(Me4NOH.5H2O)∶n〔HSi(CH3)2Cl〕=1∶1∶4,产率80%。FTIR和NMR研究证明,所得产物为Q8M8H;SEM、EDS和XRD研究表明,所制备的Q8M8H具有较高的纯度和完整的晶型结构,属于单斜晶系,a=1.18 nm,b=1.52 nm,c=1.51nm,α=γ=90°,β=108°;TG表明,Q8M8H热失重5%时的温度为210℃。     

笼形八聚（五甲基二硅氧）倍半硅氧烷

以等量的四乙氧基硅烷与四甲基氢氧化铵在水溶液中反应能够选择地形成笼形结构的八聚（四甲基铵）硅酸盐,将它用五甲基氯二硅烷进行硅烷化处理,合成出了笼形八聚（五甲基二硅氧）倍半硅氧烷,并用核磁共振^1H、^13C、^29Si NMR,红外光谱FT－IR,凝胶渗透色谱GPC进行了表征和确认。     

含活性氢基的八聚笼型倍半硅氧烷的合成与表征

笼形倍半硅氧烷具有较低的介电常数。采用正硅酸乙酯和季铵碱为原材料,合成了八聚四甲基铵基笼型倍半硅氧烷,并采用二甲基氯硅烷对其进行烷基取代,得到了含活性氢基的八聚笼型倍半硅氧烷。采用核磁共振29Si、13C、1H谱和凝胶渗透色谱GPC对其结构进行了表征和确认。     

一种星形大分子引发剂的合成与表征

本文以笼形八聚(二甲基硅烷基)倍半硅氧烷(Q8M8H)?烯丙醇??-溴代异丁酰溴为原料通过氢化硅烷化反应和酯化反应合成了八聚(2-溴-2-甲基异丁基硅氧基)倍半硅氧烷(OBPS)星形大分子引发剂,并通过FTIR、1H-NMR、29Si-NMR和GPC对其结构进行了表征,讨论了溶剂?温度和时间对产物结构和产率的影响?最佳反应条件为:以THF为溶剂,0℃反应3h,室温下反应20h,产率可达85.0%?该化合物可进一步做为原子转移自由基聚合的引发剂制备星形聚合物?     

多氧取代环己基甲醇苯甲酸酯的合成及其表征

以莽草酸为原料,经酯化、丙酮叉保护顺式邻二羟基、叔丁基二甲基硅烷保护羟基、还原、羟基酯化、最后双羟基化反应,得到多氧取代环己基甲醇苯甲酸酯(1),总产率为84.1%,其结构经IR、1H NMR和HR MS确证。对双羟基化反应的条件进行了探索,优化条件为:反应时间为15h,溶剂为THF∶H2O=1∶1(V∶V),配料比为n[(3R,4R,5R)-5-叔丁基二甲基硅氧基-3,4-(丙酮叉二氧)-环己基-1-烯烃-1-甲醇苯甲酸酯(5)]∶n(N-甲基吗啉氮氧化物)∶n(OsO4)∶n(手性配体)=100∶150∶0.5∶1,产率为90.6%,e.e.值为75.1%。     

γ-氯丙基二甲基甲氧基硅烷的催化合成

对γ-氯丙基二甲基甲氧基硅烷的合成进行了研究,在催化剂(氯铂酸作主催化剂,三正丁胺为助催化剂)的作用下γ-氯丙烯与二甲基氯硅烷通过硅氢加成反应生成γ-氯丙基二甲基氯硅烷,蒸馏提纯后,再与甲醇进行醇解反应得最终产品。通过探究反应温度、投料比、催化剂用量等反应条件达到合成工艺的最优化,γ-氯丙基二甲基甲氧基硅烷收率可达69.0%。     

一种星型聚合物引发剂的合成与表征

以笼形八聚(二甲基硅烷基)倍半硅氧烷(Q8M8H)、烯丙醇、α-溴代异丁酰溴为原料,通过硅氢加成反应和酯化反应合成了八聚(2-溴-2-甲基异丁基硅氧基)倍半硅氧烷(OBPS)星型引发剂,并通过FTIR1、HNMR、29S iNMR和GPC对其结构进行了表征,讨论了溶剂、温度和时间对产物结构和产率的影响。酯化反应的最佳反应条件为:以四氢呋喃(THF)为溶剂,0℃反应3 h,室温反应20 h,产率可达85.0%。     

2,2,4-三甲基-2-硅杂吗啉的合成

研究了氯甲基二甲基氯硅烷与β-氨甲基乙醇反应制备2,2,4-三甲基-2-硅杂吗啉的方法,考察了反应温度、反应物的配比优化和中和试剂的种类对合成产率的影响,确立了最佳的合成条件:反应物氯甲基二甲基氯硅烷与β-氨甲基乙醇的摩尔比为1∶1.05,甲苯为溶剂,三乙胺为中和试剂,其用量三乙胺与氯甲基二甲基氯硅烷的摩尔比为2.2∶1,醇解反应温度为65℃,收率可达75%,并采用波谱分析确证了目标物质的结构。     

1-(4-七甲基环四硅氧烷丙氧基苯基)-m-碳硼烷的合成与表征

以1-(4-羟基苯基)-m-碳硼烷、烯丙基溴为原料,无水碳酸钾为吸收剂,丙酮为溶剂,制备了1-(4-丙烯氧基苯基)-m-碳硼烷;然后将其与七甲基环四硅氧烷反应(以氯铂酸异丙醇溶液为催化剂),制备了1-(4-七甲基环四硅氧烷丙氧基苯基)-m-碳硼烷。研究结果表明:当n[1-(4-羟基苯基)-m-碳硼烷]∶n(烯丙基溴)∶n(K_2CO_3)=1.0∶1.2∶1.8、反应时间为12 h时,1-(4-丙烯氧基苯基)-m-碳硼烷的产率(为73.0%)相对最大;当反应时间为8 h、反应温度为40℃和n(七甲基环四硅氧烷):n[1-(4-丙烯氧基苯基)-m-碳硼烷]=1.0∶1.2时,1-(4-七甲基环四硅氧烷丙氧基苯基)-m-碳硼烷的产率(为80.1%)相对最大。     

超声波辐射合成4-(4-氯苯基)-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮

研究了超声波辐射合成4-(4-氯苯基)-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮,确定了最优合成工艺条件:n(4-氯苯甲醛)∶n(乙酰乙酸乙酯)∶n(尿素0.03 mol)=1.0∶1.2∶1.5,催化剂氨基磺酸用量0.6 g,超声波功率120 W,辐射时间45 min,产物产率为98.4%。     

微波/Fenton试剂/钛掺杂笼型八聚倍半硅氧烷协同处理苯胺模拟废水研究

以自行合成的一种新型的钛硅固体材料——钛掺杂笼型八聚倍半硅氧烷进行吸附处理苯胺废水。实验中对各条件下体系中苯胺去除率的影响进行了考察;同时,对该体系下苯胺中氨基生成N2的选择性和微波/Fenton试剂条件下催化剂的再生损失和使用寿命作了相应研究。     

Silicate polymerization during the hydration of alite

The influence of admixtures and curing temperature on silicate polymerization during the hydration of alite was studied. Trimethylsilyl derivatives were separated by gel permeation chromatography. The major species identified in the hydrated pastes were dimer, linear pantamer, and linear octamer; at later ages, particularly at higher temperature, higher polymers are formed. A polymerization scheme is proposed. The effect of admixtures on silicate polymerization exactly parallels their effects on hydration.     

硅系阻燃剂研究进展

综述了近年来有关硅系阻燃剂的结构与性能以及阻燃改性等方面的研究进展。介绍了无机硅系阻燃剂 (包括聚合物/层状硅酸盐以及聚合物/二氧化硅纳米复合材料)的热稳定性和阻燃性能。侧重论述了有机硅系阻燃剂(包括本质阻燃聚合物、笼状倍半硅氧烷及其改性聚合物)的热稳定性、阻燃性能和阻燃机理。     

Synthesis of Open Zeolite Structures from Mixtures of Tetramethylammonium and Benzylmethylalkylammonium Cations: A Step Towards Driving Aluminium Location in the Framework

Three bulky organic cations, benzylmethylpyrrolidinium (BMP), (S,S)-2-hydroxymethyl-1-benzyl-1-methylpyrrolidinium (BML) and benzylmethylhexamethyleniminium (BMH), were used in combination with the small cation tetramethylammonium (TMA) in the synthesis of zeolite materials. Two of them are distinguished by the number of carbon atoms forming the cyclic amine, which varies from 4 in BMP to 6 in BMH. In addition, a –CH₂–OH group has been introduced in the carbon atom belonging to the amine ring next to the nitrogen atom, to originate a chiral molecule, BML, the third SDA used in this work. It has been found that the combination of the small TMA with those three bulkier SDAs, promotes the crystallization of zeolite structures that contain cages and channels. BMP leads to the crystallization of the 10-ring zeolite ferrierite, where TMA is located inside the ferrierite cage. If the size of the N-cyclic amine moiety increases, the resulting cation cannot be accommodated in the relatively narrow 10-ring channels of ferrierite, and in these cases the zeolite MCM-22 crystallizes. This zeolite contains large cages whose cross section is delimited by a 12-ring, where both BMH and BML can be easily accommodated. In this system, cage-like, chlatrasil type structures often co-crystallize with the open structures, evidencing that an appropriate balance between TMA and the bulky SDA is required to achieve the crystallization of open-frameworks. When BMP is used, mixtures of structurally related ferrierite and cage-like RUB-10 are obtained if an excess of TMA is present in the synthesis gel, while MCM-22 crystallizes together with the structurally related cage-like MTN phase.     

Sol–Gel Processing of Tetramethylammonium Silicate

A new sol–gel silica material based on tetramethylammonium silicate (TMAS) is reported here. Both xerogels and aerogels were produced by gelling a solution of 18.7 wt% TMAS using a series of esters. The gelation kinetics was controlled by varying the type and concentration of the ester. The supercritically dried TMAS aerogel was seen to have a larger pore size distribution with high porosity (>90%). In contrast, the conventionally dried gel showed a narrow distribution of mesopores, indicating its potential as a host matrix for protein encapsulations and catalysts.     

笼式反应器中的流动与混合特性

以工业笼式聚酯终缩聚反应器开发应用研究为背景，分别考察了介质的粘度、装料液位、转速和反应的结构对笼式反应器的流型及宏观混合时间的影响。实验表明：高粘度、高剪切和小的网盘间距有利于混合；液位增高，不利于混合；在流型上，笼体和网盘相互消除对方的搅拌死区，大大地提高了反应器的混合效率。     

MOLECULAR DYNAMICS SIMULATIONS OF FILLED AND EMPTY CAGE-LIKE WATER CLUSTERS IN LIQUID WATER AND THEIR SIGNIFICANCE TO GAS HYDRATE FORMATION MECHANISMS

Molecular dynamics simulations are performed to observe the evolutions of 512 and 51262 cage-like water clusters filled with or without a methane molecule immersed in bulk liquid water at 250 K and 230 K. The lifetimes of these clusters are calculated according to their Lindemann index δ (t) using the criteria of δ≥0.07. For both the filled and empty clusters, we find the dynamics of bulk water determines the lifetimes of cage-like water clusters, and that the lifetime of 512 62 cage-like cluster is the same as that of 512 cage-like cluster. Although the methane molecule indeed makes the filled cage-like cluster more stable than the empty one, the empty cage-like cluster still has chance to be long-lived compared with the filled clusters. These observations support the labile cluster hypothesis on the formation mechanisms of gas hydrates.