羟甲基酚制备单宁基胶黏剂与性能

以杨梅单宁为原料,以羟甲基酚作为单宁基胶黏剂键桥增长剂,分析了羟甲基酚对单宁基胶黏剂适用期及其制备的胶合板耐水性影响,并对相关制备工艺进行优化。结果表明,以羟甲基酚作为单宁基胶黏剂键桥增长剂所制备的单宁基胶黏剂耐水性略低于普通酚醛树脂,但施胶性能和适用期优于普通酚醛树脂。单宁基胶黏剂最佳制备工艺为:羟甲基加量10%,甲醛加量6%,热压温度180℃,热压时间3min。

交联剂-多羟甲基酚的制备

为了制备性能更优异的大豆蛋白基胶黏剂,本研究采用"低温-保碱"工艺,以高浓度甲醛制备多羟甲基酚作为后续大豆蛋白基胶的交联剂使用,并借助电喷雾电离质谱仪(ESI-MS)和核磁共振(13C-NMR)进行表征。结果表明,最终合成的交联剂羟甲基总含量和多羟甲基含量较高,反应48 h制备的交联剂羟甲基总含量和多羟甲基含量分别高达94.9%和76%,并且体系中的游离甲醛或甲醛聚合物含量微乎其微(1.1%),后续可直接用于大豆蛋白胶的交联改性。多羟甲基酚基本是以2个三羟甲基酚或者1个三羟甲基酚和1个二羟甲基酚的二聚体形式存在。二聚体的存在并没有减少可以反应的活性点,使得可以参加后续缩聚反应的游离羟甲基更多,可能更容易与蛋白质分子形成大分子网状结构。

多羟甲基酚多丙烯酸酯的合成及其耐温性能研究

本文合成了新型耐温活性预聚体多羟甲基酚多丙烯酸酯,并考察了pH值,丙烯酸量,反应时间、反应温度、催化剂用量等因素对反应产率的影响。测试了固化物的TCA和DTA及力学性能,并用红外光谱确认主产物。

羟甲基酚丙烯酸酯的合成及粘接性能

以甲醛、苯酚和丙烯酸为原料,经缩合、酯化反应合成了多羟甲基酚丙烯酸酯。考察了胶样的破坏强度、耐热性、稳定性以及N-苯基马来酰亚胺对胶样耐热性的影响。结果表明,以多羟甲基酚丙烯酸酯为活性单体,可制一种新型厌氧性耐热胶粘剂。此外,N-苯基马来酰亚胺可明显改善胶样的耐热性能。

无醇啤酒中的酚类及其相关物质

本文研究并比较了几种市场的无醇及普通啤酒中酚类物质的组成。一般来说，酚类物质在无醇啤酒中的含量比普通啤酒低，这是由于酿制无醇啤酒时采取的发酵过程及选用的菌株不同而造成的，而且在无醇啤酒的脱醇处理过程中也会带来部分损失。通常认为，无醇啤酒中其低分子复合物的含量比普通啤酒中的少，如5-（羟甲基）糠醛。

用DEPT135测定Resol的组成及微细结构参数

通过对resol(羟甲基酚化合物和低分子量羟甲基酚树脂)DEPT135图谱的分析讨论,得到一系列计算resol微细结构参数的经验公式。根据DEPT135图谱可判断是否发生缩聚反应,根据经验公式可计算酚单体各个活性点参与反应百分率或酚羟基导入率、不同类型缩聚所占百分率及低分子量羟甲基酚树脂的平均核体数。

新型厌氧性耐高温胶粘剂

研究了一种以甲醛、苯酚和丙烯酸为原料合成的新型厌氧性耐高温胶粘剂 .考察了稳定性、耐热温度。

一种堵水剂用交联剂的研制与性能评价

HPAM凝胶是目前国内外采用最广泛、最有效的化学堵水剂,其中苯酚/甲醛体系是HPAM凝胶类堵水剂最常用的交联剂。但是苯酚/甲醛交联剂气味和毒性较大,尤其是高致癌性,严重限制了其在现场的应用。针对这一问题,本文首先在室内合成了低毒无气味的水溶性羟甲基多酚THMBPA,然后以THMBPA为交联剂主剂,以多乙烯多胺TET为交联剂辅剂,研究了部分水解的聚丙烯酰胺HPAM与THMBPA/TET复合交联剂的凝胶动力学,考察了pH、复合交联剂配比、温度以及盐浓度对成胶时间和凝胶长期稳定性的影响。结果表明,在90℃和120℃下,该凝胶体系的成胶时间可在10～120h任意调节;凝胶长期耐温稳定性好,在120℃下凝胶可稳定存在90d,在90℃下可稳定存在100d;长砂管封堵驱油实验表明,该堵水剂具有良好的封堵能力,封堵率可达90.6%。

新型耐温堵水调剖剂的研制与性能评价

HPAM凝胶是目前国内外采用最广泛、最有效的化学堵水调剖剂,其中苯酚/甲醛体系是HPAM凝胶类堵水调剖剂最常用的交联剂。但是苯酚/甲醛交联剂气味和毒性较大,尤其是高致癌性,严重限制了其在现场的应用。首先,在室内合成了低毒水溶性的羟甲基多酚THMBPA;其次,以THMBPA为交联剂主剂,以多乙烯多胺TET为交联剂辅剂,研究了部分水解的聚丙烯酰胺HPAM与THMBPA/TET复合交联剂的凝胶动力学,考察了p H值、复合交联剂配比、温度对成胶时间和凝胶长期稳定性的影响。实验结果表明,在120℃下,该凝胶体系的成胶时间可在10~120 h范围内任意调节。在120℃下凝胶可稳定存在90 d,在90℃下可稳定存在100 d。

Synthesis and protein tyrosine phosphatase 1B inhibition activities of two new synthetic bromophenols and their methoxy derivatives

3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B （PTP1B）. Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-（2＇-bromo-6＇-（3＂,4＂-dimethoxybenzyl）- 3 ＇,4 ＇-dimethoxybenzyl）-4,5 -dimethoxybenzene （2）, 2,3-dibromo- 1 -（2 ＇-bromo-6＇-（2 ＂-bromo-4＂,5 ＂-dimethoxy- benzyl）-3＇,4＇-dimethoxybenzyl）-4,5-dimethoxybenzene （3）, 3,4-dibromo-5-（2＇-bromo-6＇-（2＂-bromo-4＂,5＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （4） and 3,4-dibromo-5-（2＇-bromo-6＇-（3＂,4＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （5）. PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.

Preparation of natural α-tocopherol from non-α-tocopherols

Non-a-tocopherols are hydroxymethylated and hydrogenated to produce α-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5% Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180 ℃ to 200 ℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1 g/100 g, and reaction time 5.0 h. A product with α-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-α-tocopherols is almost 100%, and the mole yield of a-tocopherol is more than 90%.

New Constituents from the Fresh Stems of Opuntia Dillenii

Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids of NMR and MS spectral analysis. Result Three newcompounds, together with 14 known compounds, were isolated form the 80% ethanolic extract of itsstems. Conclusion The three new compounds, opuntioside Ⅰ (2), 4-ethoxyl-6-hydroxymethyl-α-pyrone(3) and kaempferol 7-O-β-D-glucopyranosyl (1→4)-β-D-glucopyranoside (4), were characterized.

Pomegranate （Punica granatum L.） Peel Extract as a Source of Natural Antioxidant

An increase in the demand for natural additives has shifted the attention from synthetic to natural antioxidants. Antioxidative components from pomegranate peel were extracted by using different solvents like methanol, ethanol, acetone, chloroform and ethyl acetate. All the extracts were tested for Total phenolic content （TPC） and the methanol which proved to be best in extracting the phenolic compounds was used to assess the antioxidant property by using different methods like Diphenyl piridyl picryl hydrazyl （DPPH）, Relative reducing power （RRP）, Beta carotene bleaching and Ferric thiocyanate （FTC）. The antioxidant activity （AA） of pomegranate peel extract （PPE） was compared with Butylated hydroxyl toluene （BHT） and Butylated hydroxyl anisole （BHA）. The methanolic extract was examined by Liquid Chromatography and Mass Spectroscopy （LCMS） and the spectra showed the presence of different phenolic compounds. The extracts were tested for their efficiency in preventing rancidity of Refined Bleached Deodorized Soybean oil （RBDSBO） in comparison with BHT and control at 200 ppm concentration. The PPE proved to be best in preventing rancidity. Owing to the present results, the studies can further be extended to exploit the PPE for application into different food products.

Cause and control of Radix Ophiopogonis browning during storage

In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatogra- phy （HPLC） and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron mi- croscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural （5-HMF）, total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were de- creased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning （Y） could be described by following correlation equation： Y= - 0.625 4 ＋ 0.020 84 × X3 ＋ 0.001 514×X1×x X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity （HR）, temperature, and moisture content were under 25% RH, 12 ℃ and 18%, respectively.