A novel associative latex thickener using ethoxylated behenyl methacrylate as functional monomer

Alkali-soluble associative latex thickeners modified with hydrophobic long chain alkyl groups were prepared using common acrylics and varying amount of a functional monomer,ethoxylated behenyl methacrylate(BEM),through emulsion polymerization.It was found that the size of the emulsion particle became larger with addition of BEM.The light transmittance of the thickener latex sharply increased with pH varied from 6 to 7.The associative latex thickener manifested a higher viscosity when solids in the latex thickeners were kept at 0.5 wt%or higher,and the optimal amount of BEM was found to be around 2.5 wt%,or 0.16 mol%.All thickener latexes modified with BEM have better shearing resistance than the BEM-free thickener.

New Family of Functionalized Monomers Based on Amines: A Novel Synthesis that Exploits the Nucleophilic Substitution Reaction

Chemistry modifications are usually performed to introduce specific group that can increase properties and functionality of materials. In this study, we present the synthesis of six new functionalized monomers prepared by nucleophilic substitution reactions. Reaction of aliphatic and aromatic amines with acryloyl chloride at –20ºC, in presence of triethylamine allowed the synthesis of the corresponding amides. Proton nuclear magnetic resonance (1H NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and ultraviolet- visible (UV-Vis) measurements confirmed the success of the synthesis with a yield over 90%. These compounds emerged as potentially attractive monomers since they can be used to obtain stimuli-sensitive polymeric materials, due to the presence of amide and pyridine groups.

RADICAL POLYMERIZATION OF N, N-DI(2-2'-METHYL-ACRYLOYLOXY-PROPYL)-PARA-TOLUIDINE FUNCTIONAL MONOMER

Functional monomer (MP)_2PT having tertiary aromatic amino group was systhesized from the reaction of N, N-di (2-hydroxypropyl)-p-toluidine with 2-methyl acryloyl chloride. In the presence of organic peroxide, the radical polymerization of (MP)_2PT in toluene took place. The kinetics of (MP)_2PT polymerization and the ESR spectra of LPO-(MP)2PT-MNP systems were determined respectively.

Association of Fibrin Monomer Polymerization Function, Cerebrovascular Risk Factors and Ischemic Cerebrovascular Disease in Old People

In order to investigate the association of fibrin monomer polymerization function (FMPF) with traditional cerebrovascular risk factors and ischemic cerebrovascular disease in old people. 1∶1 paired case-control comparative study was performed for FMPF and traditional cerebrovascular risk factors on 110 cases of old ischemic cerebrovascular disease and 110 controls matched on age, sex and living condition. The results showed that cerebrovascular risk factors were more prevalent in case group than in control group. In the case group, FMPF was significantly higher than in control group. There was a significant positive correlation between hypertension and fibrin monomer polymerization velocity (FMPV), hypertension and fibrinogen (Fbg), alcohol consumption and Fbg, but no significant correlation between diabetic mellitus, smoking and FMPF was found. Among the parameters of blood lipids, there were significant positive correlations between total cholesterol (TC) and parameters of FMPF to varying degrees, triglycerides (TG) and FMPV, TG and Fbg. Our results also showed there were significant linear trends between TC and FMPV (P<0. 001), TC and Fbg (P=0. 0087), TG and FMPV/Amax (maximum absorbance)(P=0. 0143) respectively. Multiple logistic regression analysis revealed that FMPF in case group remained significantly higher than control group after adjustment of all risk factors that were significant in univariate analysis. It was concluded that there is a possible pathophysiological link between FMPF and cerebrovascular risk factors. An elevated FMPF is associated with ischemic cerebrovascular disease and an independent risk factor of this disease. In old people, detection of FMPF might be a useful screening to identify individuals at increased cerebrothrombotic risk.

Synthesis of Micron-size Functional Polystyrene Fluorescent Micro- spheres and their Adsorbability to Human Serum Albumin

Polystyrene microspheres with sulfo- or aldehyde- surface were synthesized through dispersion polymerization. Functional polystyrene fluorescent microspheres were prepared by the way of adding 2, 5-diphenyloxazole (PPO) into the reaction system directly and dying the blank microspheres in the ethanol solution of PPO. The influence of preparing matters on the encapsulating rate of PPO, and the influence of functional groups on the adsorbability to human serum albumin (HSA) were investigated.

ETHYLENE POLYMERIZATION AND COPOLYMERIZATION WITH POLAR MONOMERS BY A NEUTRAL NICKEL CATALYST COMBINED WITH CO-CATALYST OF Ni(COD)_2 OR AL(i-Bu)_3

A neutral nickel(Ⅱ)catalyst D,{[O-(3-cyclohexyl)(5-Cl)C_6H_2-ortho-C(H)=N-2,6-C_6H_3(i-Pr)_2]Ni(Ph_3P)(Ph)}hasbeen synthesized and characterized by IH-NMR,FTIR and elemental analysis.The results indicate that Al(i-Bu)_3 is aneffective cocatalyst for the neutral nickel catalyst.With bis(1,5-cyclooctadiene)nickel(0)[Ni(COD)_2]or Al(i-Bu)_3 as a co-catalyst,the neutral nickel catalyst D is active for ethylene polymerisation and copolymerisation with polar monomers(tert-butyl 10-undecenoate(BU),methyl 10-undecenoate(MU),allyl alcohol(AA)and 4-penten-1-ol(PO))under mild conditions.The resulting polymers were characterized by (?)H-NMR,FTIR,DSC,and GPC.From the comparative studies,Ni(COD)_2 ismore active than Al(i-Bu)_3 for ethylene homopolymerization,while Al(i-Bu)_3 is more effective than Ni(COD)_2 for ethylenecopolymerisation with polar monomers.The polymerization parameters which affect both the catalytic activity and propertiesof the resulting polyethylene were investigated in detail.Under the conditions of 20 μmol catalyst D and Ni(COD)_2/D=3(molar ratio) in 30 mL toluene solution at 45℃,12×105 Pa ethylene for 20 min,the polymerization activity reaches ashigh as 7.29×105 gPE.(mol.Ni.h)^(-1) and M_η,is 7.16×104 g.mol^(-1).For ethylene copolymerization with polar monomers,theeffect of comonomer concentrations was examined.As high as 0.97 mol% of MU,1.06 mol% of BU,1.04 mol% of AA and1.37 mol% of PO were incorporated into the polymer,respectively,catalyzed by D/Al(i-Bu)_3 system.

等温滴定量热法研究镉离子与GMP的亲合机理

利用等温滴定量热法研究镉离子与鸟嘌呤核糖核苷酸(GMP)的亲合过程,重点分析不同比例的镉离子和GMP结合时的异同,实验结果显示:(1)镉离子和GMP的浓度比不同会对二者的结合过程产生显著影响,在低浓度比下,反应为焓驱动的放热反应;在高浓度比下,反应为吸热反应。从镉离子和GMP浓度比为20∶1时的ITC滴定曲线和OneSite模型拟合结果可知,镉离子和GMP是接近并按照1∶1的比例结合的,二者的亲合力K值为1.21E 4±2.26E 3。(2)推测GMP与镉离子有两个结合位点,一个为放热结合位点,一个为吸热结合位点,在低浓度比下,只有放热结合位点发生结合。当浓度比到达一定值后,会激活吸热结合位点,同时发生吸热结合和放热结合。因为吸热结合位点的结合能力更强,最终可能呈现为吸热反应。(3)通过反滴法和正滴法的比较,同一浓度下,不同的滴加方式也会对结合结果造成较大的影响。该研究所采用的方法可以很好地从宏观的热力学角度分析金属镉离子与GMP的亲合机理,以期为后续镉离子印迹物制备过程中功能单体的筛选提供重要的试验基础和理论指导。

镍催化剂用于制备乙烯-丙烯酸甲酯共聚物的研究进展

综述了近年来基于镍催化剂催化乙烯与丙烯酸甲酯(MA)配位共聚制备乙烯-丙烯酸甲酯共聚物(EMA)的最新研究进展。简要概括了从前过渡金属Ziegler-Natta催化剂,到茂金属催化剂,再到后过渡金属镍钯催化剂的发展历程。根据配体的种类对镍催化剂进行分类总结,包括[N,N]型、[N,O]型、[P,O]型、[N,P]型等二齿镍催化剂及[N,N,O]型三齿镍催化剂。后过渡金属镍催化剂因具有良好的极性单体耐受性,在催化乙烯与MA共聚取得了显著进展,通过开发新型镍催化剂实现乙烯与MA共聚制备EMA的工业化进程将越来越近。

基于分子模拟的功能单体筛选用于毒死蜱分子印迹聚合物制备

以毒死蜱(Chlorpyrifos, CPF)为模板,采用Materials Studio分子模拟(Molecular simulation, MS)软件及紫外光谱法分析不同功能单体与模板分子间相互作用,并通过吸附实验验证最优功能单体。在测试的5种功能单体中,4-乙烯基苯甲酸(4-Vinylbenzoic acid, VBA)与CPF相互作用能最小(-12.063 3 kcal/mol),预组装所形成的复合物稳定性最好。吸附实验结果表明,以VBA为功能单体制备的MIPs相比于以甲基丙烯酸(MAA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)及丙烯酰胺(AM)为功能单体制备的MIPs拥有更优异的吸附容量,VBA与CPF物质的量比为1∶2时所制备的MIPs对CPF有高效的特异性识别能力。试验结果可为进一步研究其他类型农药分子印迹聚合物的吸附和识别机理提供理论基础。

新型抗泥聚羧酸减水剂的合成及性能研究

氯丙烯封端脂肪醇聚氧乙烯醚(AC-AEO9)作为一种可聚合型表面活性剂,具有较大的空间位阻。使用AC-AEO9作为抗泥功能单体,制备了新型抗泥聚羧酸减水剂(A-PCE),并考察了功能单体用量对A-PCE分散性和抗泥性的影响,采用X射线衍射仪与比表面与孔径分析仪揭示了A-PCE的抗泥机理。结果表明,在减水剂掺量为0.23%、功能单体与减水剂大单体摩尔比为1∶5的条件下,掺A-PCE的水泥净浆初始、120 min流动度为275、270 mm,减水剂表现出最佳的分散性和抗泥性;由于抗泥功能单体的引入,聚羧酸减水剂具有良好的分散性且在黏土上吸附更少,对黏土的适应性更强。

含抗泥功能单体的聚羧酸减水剂的制备及抗泥性能

采用聚乙二醇400(PEG400)合成了一种新型抗泥功能单体(FM),并将其引入到聚羧酸减水剂(PCE)的分子结构上,制备了几种抗泥型聚羧酸减水剂(AC-PCE)。采用傅里叶红外光谱(FT-IR)对FM和PCE进行表征,分别通过净浆流动度和砂浆流变性试验考察PCE在含蒙脱土(MMT)水泥净浆和水泥砂浆中的分散性能,并研究了PCE在MMT上的吸附特性。结果显示,与不含FM的聚羧酸减水剂相比,AC-PCE减少了在MMT上的吸附量,抑制了MMT的插层吸附,降低了含MMT水泥净浆经时流动度损失以及含MMT水泥砂浆的屈服应力。研究表明,AC-PCE具有良好的抗泥性能。

Polyhydroxyurethanes from Biobased Monomers and CO_(2):A Bridge between Sustainable Chemistry and CO_(2) Utilization

Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phosgene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic carbonate)precursors bearing multiple carbonate moieties(multi-5CCs)is a key requisite for preparing PHUs by polyaddition reaction with bis-or polyamines.Producing sustainable PHUs from CO_(2)-based five-membered cyclic carbonates(5CCs)obtained from biobased epoxides is a valuable strategy to bridge CO_(2) utilization and the upcycling of renewable substrates.In this context,while many multi-5CC monomers reported in the literature are oil-based,recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO_(2) and renewable resources such as fatty acids and vegetable oils,lignin,terpenes,and sugars.In this work,recent crucial advances(2019—2023)on PHUs prepared from bis-and multi-5CCs produced from CO_(2) and(partially/potentially)biobased substrates are reviewed with respect to their synthesis,thermal and mechanical properties,and their recent,emerging applications.

基于AB型单体聚醚酰亚胺共聚物的合成与性能

将AB型单体3-氨基-5,6,9,10-四氢-[5]螺旋烯-7,8-二羰基-二甲酸酐(ATHDA)与4,4’-(4,4’-异亚丙基二苯氧基)双(邻苯二甲酸酐)(BPADA)和4,4’-二氨基二苯醚(ODA)通过高温一步法共聚,制备了一系列ATHDA含量不同的聚醚酰亚胺PEI-AB_(x)(x为ATHDA用量,以BPADA和ODA的总质量计,下同)。采用FTIR、~1HNMR、DSC、DMA、TGA对聚合物进行了表征,对其力学性能和溶解性进行了测试。结果表明,PEI-AB_(x)特性黏数在0.60~0.87 dL/g之间,均具有良好的成膜性,且该系列聚合物在常见的有机溶剂N,N-二甲基乙酰胺、N-甲基吡咯烷酮中均具有优异的溶解性;由DMA测得的玻璃化转变温度(T_(g))在228~256℃之间,N_(2)气氛下5%热失重温度(T_(5%))为505~536℃,表明PEI-AB_(x)具有优异的热稳定性;聚合物薄膜的拉伸强度、杨氏模量和断裂伸长率分别在41.7~88.1 MPa、1.7~2.7 GPa和3.3%~4.8%之间,具有良好的力学性能。另外,聚合物分子链中的四氢-[5]螺旋烯结构可脱氢芳构化,与PEI-AB_(20)相比,芳构化后PEI-AB_(20)的T_(g)从256℃提高至283℃,T_(5%)从531℃提升至557℃,表明芳构化后聚合物耐热性得到进一步提升。

不同功能单体浓度的丙烯酸酯压敏胶制备及其性能研究

采用溶液聚合法,以软单体丙烯酸-2-乙基己酯、硬单体丙烯酸甲酯功能单体丙烯酸和溶剂乙酸乙酯为原料,经引发剂偶氮二异丁腈,交联剂乙酰丙酮铝作用,制备不同胶层厚度的溶剂型丙烯酸酯压敏胶,探究不同功能单体浓度对丙烯酸酯压敏胶性能的影响。研究结果表明:当胶层厚度为30μm,丙烯酸浓度为10.96%,丙烯酸酯压敏胶的180°剥离强度最大值为2730.5 gf·(25 mm)^(-1);当胶层厚度为30μm,丙烯酸浓度为5.80%,环形初粘力最大值为16.559 N·(25 mm)^(-1);当胶层厚度为20μm,丙烯酸浓度为8.45%和10.96%时,位移量均为0.5 mm,持粘性好。因此,当胶层厚度为30μm,浓度为8.45%时,丙烯酸酯压敏胶的综合性能较好。

中药干预肿瘤微环境中免疫细胞的研究进展

肿瘤微环境(TME)是肿瘤细胞生长的内外环境,与肿瘤细胞的发生、生长及转移都密切相关,也是抗肿瘤药物作用的关键靶点。中药具有正向调节免疫杀伤细胞数量和功能、下调免疫抑制细胞数量和功能的作用,在一定程度上改善了TME,从而有望缩小瘤体,同时改善患者预后和提高生命质量。现以抗肿瘤中药是否通过调节TME、重塑机体的免疫功能、杀灭肿瘤细胞,尤其对TME中关键免疫细胞的调节作用为研究重点,从中药(包括单体)、复方、中成药注射液3方面开展其对TME中免疫细胞的干预作用总结,以期为后续开展深入的中药干预TME的实验和临床研究奠定基础。

桐油酸改性含环氧基团聚丙烯酸酯乳液的制备

以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸羟乙酯(HEA)为主要单体,桐油酸和甲基丙烯酸缩水甘油酯(GMA)为功能性单体,采用半连续乳液聚合法制备了一系列桐油酸改性含环氧基团聚丙烯酸酯乳液(简称改性聚丙烯酸酯乳液)。通过FTIR表征胶膜的结构,测定了胶膜的耐水性能、力学性能、热稳定性、耐酸碱性。结果表明,当桐油酸含量(以MMA、BA、HEA、GMA的总质量为基准)为4%时,随着GMA含量(即GMA质量占总丙烯酸酯单体质量的百分数,下同)的增加,胶膜铅笔硬度增大,耐水、耐酸碱性能增强,拉伸强度增大,热稳定性增加,胶膜附着力增加。当GMA含量为12%时,胶膜铅笔硬度为4H,涂在马口铁上的胶膜在质量分数为5%的盐酸溶液中浸泡144 h无变化,在质量分数为5%的NaOH水溶液浸泡72h无变化,24 h的吸水率为3.31%,附着力为0级。

基于复合功能单体噻菌灵印迹传感器的制备及应用

目的:快速检测食品中噻菌灵残留量。方法:通过紫外光谱法筛选邻氨基苯酚和邻苯二胺作为复合功能单体,采用电化学分析法研究了聚合条件、洗脱条件,对传感器性能进行了评价,建立了食品中噻菌灵残留的快速检测方法。结果:在最佳条件下,该印迹传感器对噻菌灵及其结构类似物具有特异吸附性能,且对噻菌灵的选择性最强;该方法的线性范围在1×10^(-8)~1×10^(-4)mol/L,检出限为3.3×10^(-9)mol/L,样品加标平均回收率为88.16%~100.73%,相对标准偏差(RSD)≤2.63%。结论:该传感器具有优异的印迹效应以及良好的选择性、重现性与稳定性,可用于食品中噻菌灵残留的快速检测。

一种新型降黏型聚羧酸减水剂的制备及应用

以甲基丙烯酸酯嵌段聚醚(JHE-220)、丙烯酸(AA)、甲基烯丙基磺酸钠(SMAS)为主要原料,通过共聚反应合成降黏型聚羧酸减水剂PCZ-100。研究酸醚比、反应温度、链转移剂用量、引发剂用量对减水剂性能的影响,测试了降黏型减水剂与减水型减水剂复配比例对混凝土性能的影响。结果表明,PCZ-100的最佳合成条件为:n(JHE-220)∶n(AA)∶n(SMAS)=1.0∶3.5∶0.3,引发剂过硫酸铵、链转移剂3-巯基丙酸用量分别为单体总质量的1.2%、1.7%,反应温度为65~70℃。减水型减水剂PCA-800与最佳工艺合成的PCZ-100按4∶3质量比复合使用可以明显降低混凝土的黏度并且保证混凝土强度。

甾烷类化合物分子印迹聚合物功能单体的筛选及MIPs制备

为了制备对甾烷类化合物具有特异性选择能力的分子印迹聚合物(MIPs),利用紫外光谱法对预聚合体系进行筛选,确定功能单体的种类、配比及其作用方式。将3种模板分子(胆固醇、β-谷固醇、去氧胆酸)分别与4种功能单体,即丙烯酸(AA)、甲基丙烯酸(MAA)、甲基丙烯酸甲酯(MMA)、丙烯酰胺(AM)的相互作用强度进行对比。研究结果发现,功能单体AA均可与3种模板分子发生较强的相互作用并形成稳定的预聚合体系,从而优选出AA为MIPs的功能单体。另外,通过不同比例AA紫外光谱吸光度变化和差示紫外光谱分析,显示3种模板分子与功能单体AA的最佳浓度比均为1∶4,且形成的稳定配合物构型分别为胆固醇-1AA、β-谷固醇-1AA及去氧胆酸-3AA。同时,以EDGMA为交联剂、AIBN为引发剂,采用沉淀聚合法成功合成了MIPs,傅立叶变换红外光谱(FTIR)分析结果显示MIPs制备良好。因此,此方法可用于对甾烷类化合物具有特异性选择能力的MIPs功能单体的筛选及其制备,并为深层—超深层烃源岩油源对比研究提供技术支持。