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%。     

两个ATRP大分子引发剂的合成与表征

以十二醇为引发剂,通过开环聚合反应合成单端羟基的聚己内酯(PCL),将PCL进一步与α-溴丙酰溴反应,合成了原子转移自由基聚合(ATRP)的大分子引发剂-α-溴代丙酸聚己内酯。通过α-溴丙酰溴与聚乙二醇(PEG)的反应合成了另一种ATRP大分子引发剂-α-溴代丙酸聚乙二醇酯。用1H NMR和IR证实了这两种大分子引发剂的结构。     

大分子引发剂的合成与表征

以mPEG5000为原料,采用两种方法制备了大分子引发剂mPEG-Br.大分子引发剂的结构通过IR、1H-NMR进行了表征.实验结果表明加入4-二甲氨基吡啶在反应中起了至关重要的作用,不仅使反应物的纯度增加而且大大提高了反应物的产率.     

UV固化超支化大分子光引发剂的合成与表征

以丙烯酸甲酯(MA)、二乙醇胺(DA)、三羟甲基丙烷(TMP)、丁二酸酐(SA)和2-羟基-2-甲基-1-苯基-1-丙酮(HMPP)等为原料,通过4步反应,合成了一种超支化光引发剂:HPAE-1-SA-HMPP,用FT-IR、1H-NMR、UV分析、TGA等对反应产物进行了表征.FT-IR、1H-NMR分析结果表明,合成了目标产物HPAE-1-SA-HMPP,UV分析可知其紫外最大吸收峰在330 nm,与小分子光引发剂HMPP相比,稍有红移.引发TMPTA固化实验可知HPAE-1-SA-HMPP光引发剂在5%(质鼍分数)时具有最大引发效率,引发效率略低于小分子光引发剂HMPP.     

水性UV固化涂料用超支化大分子光引发剂的合成与表征

通过季戊四醇、2,2-二羟甲基丙酸(DMPA)、甲苯-2,4-二异氰酸酯(TD I)、2-羟基-2-甲基-1-苯基-1-丙酮(HMPP)、马来酸酐等合成了一种可参与紫外光固化的超支化大分子光引发剂,利用傅里叶红外光谱、核磁共振谱、紫外、DSC、TG对其结构和性能进行了表征,发现当引发剂含量在4%时引发效果最佳,反应初始阶段大分子的引发效率高于小分子光引发剂,随着反应的进行大分子光引发剂的引发效率逐渐小于小分子。大分子光引发剂在纯水中的溶解度很小,而在含有碱性中和剂的水性光固化体系中可以很好地溶解。     

大分子光引发剂的研究进展

介绍了提氢型大分子光引发剂和新兴超支化型大分子光引发剂的最新研究进展，并对光引发剂的发展趋势进行了展望。     

一种含硅大分子光引发剂的合成及其性能研究

以2-羟基-2-甲基-1-苯基丙酮(HMPP)、异佛尔酮二异氰酸酯(IPDI)、羟基封端聚硅氧烷HOSiOH为原料,通过两步反应,合成了一种含硅大分子光引发剂HMPP-IPDI-HOSiOH-IPDI-HMPP(HISiIH)。用IR对反应过程进行了监测。通过配备有紫外光点光源的差动热分析仪(Photo-DSC)研究了HISiIH引发三丙二醇双丙烯酸酯(TPGDA)光聚合动力学。与小分子光引发剂HMPP复配,解决氧阻聚对光聚合反应的影响。     

超支化大分子光引发剂的合成与表征

以丙烯酸甲酯(MA)、二乙醇胺(DA)、三甲醇丙烷(TMP)和丁二酸酐(SA)、2-羟基-2-甲基-1-苯基-1-丙酮(HMPP)等为原料,通过4步反应合成了3种超支化光引发剂,分别为HPAE-1-SA-HMPP、HPAE-2-SA-HMPP和HPAE-3-SA-HMPP,并对产物进行了表征.产物紫外最大吸收峰比小分子光引发剂HMPP稍有红移,而且在400cm-1与500cm-1处有荧光.     

纤维素大分子引发剂的制备与表征

以阔叶浆纤维素为原料,2-溴异丁酰溴(BIBB)作溴化试剂,4-二甲氨基吡啶(DMAP)作催化剂,二氯甲烷(DCM)作为溶剂的反应体系中,制备纤维素大分子引发剂Cellulose-Br。探究反应时间、反应温度、溴化试剂用量、催化剂用量对大分子引发剂取代度(DS)的影响,并通过正交试验,确定了制备大分子引发剂的最佳工艺条件为反应温度为35℃、反应时间为32 h、溴化试剂与纤维素的摩尔比为5.5:1、催化剂与溴化试剂的摩尔比为0.6:1,产品取代度达到了0.94。红外光谱表明大分子引发剂的合成是通过酯化反应完成的。     

三嵌段共聚物大分子引发剂的合成

首先用Novozyme 435作为催化剂合成了聚己内酯-聚乙二醇-聚己内酯三嵌段聚合物,然后通过端基官能化法合成了大分子引发剂。通过核磁表征了三嵌段聚合物和大分子引发剂的结构,从而制备含氟功能五嵌段共聚物,该聚合物在很多领域具有潜在的应用价值。     

POSS/聚合物有机-无机杂化材料的研究进展

介绍了笼型倍半硅氧烷(POSS)的特点。综述了POSS/聚合物杂化材料近年来的研究进展(包括POSS/环氧树脂杂化材料、POSS/聚酰亚胺杂化材料、POSS/有机硅杂化材料、POSS/聚乙烯杂化材料、POSS/聚丙烯杂化材料和其他类型含POSS的杂化材料等),并对其应用前景进行了展望。     

Synthesis,characterization and surface properties of star‐shaped polymeric surfactants with polyhedral oligomeric silsesquioxane core

Star‐shaped amphiphilic polymeric surfactants comprising a hydrophobic polyhedral oligomeric silsesquioxane (POSS) core and hydrophilic poly(ethylene glycol) (PEG) arms with various chain lengths are successfully synthesized using copper(I)‐catalysed azide–alkyne cycloaddition (CuAAC) click reaction. Their chemical structures and molecular characteristics are clearly confirmed using Fourier transform infrared and ¹H NMR spectroscopies and gel permeation chromatography, and no homopolymer is found after CuAAC click reaction. Aqueous solutions of these star‐shaped polymers have been investigated using atomic force and transmission electron microscopies and dynamic light scattering studies and it is found that they can self‐assemble into micelles. The sizes of the micelles can be adjusted by the length of the PEG arms, where longer chains not only lead to increased micelle sizes, but also reduce the contact angle values. Moreover, the melting points and root mean square roughness of the obtained star‐shaped polymers are slightly increased on increasing the chain length of the PEG arms. © 2017 Society of Chemical Industry     

Synthesis and characterization of polyimide/polyhedral oligomeric silsesquioxane nanocomposites containing quinolyl moiety

A series of functional polyhedral oligomeric silsesquioxane (POSS)/polyimide (PI) nanocomposites were prepared using a two‐step approach. First, octa(aminophenyl)silsesquioxane (OAPS) was mixed with poly(amic acid) (PAA) prepared by reacting bis(4‐amino‐3,5‐dimethylphenyl)‐3‐quinolylmethane and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride. Second, the resulting solution was subjected to thermal imidization. The well‐defined ‘hard particles’ (POSS) and the strong covalent bonds in the amide linkage between the carbon atom of the carboxyl side group in PAA and the nitrogen atom of the amino group in POSS lead to a significant improvement in the thermal and mechanical properties. Homogeneous dispersion of POSS cages in the PI is evident from scanning electron microscopy, which further confirms that the POSS molecule becomes an integral part of the organic‐inorganic inter‐crosslinked network system. Differential scanning calorimetry and dynamic mechanical analysis show that the glass transition temperatures of the POSS‐containing nanocomposites are higher than that of the corresponding neat PI system, owing to the significant increase of the crosslinking density in the PI/POSS nanocomposites. Increasing the concentration of OAPS in the PI networks decreases the dielectric constant. Pure PI and PI/POSS systems have good antimicrobial activity. Copyright © 2011 Society of Chemical Industry     

一种耐高温聚硫代醚高分子的合成及其应用

利用巯基化合物与含烯基化合物的自由基反应合成了一种含有多面体低聚倍半硅氧烷(Polyhedral Oligomeric Silsesquioxane,简称POSS)结构的聚硫代醚高分子,并研究了这种高分子的热力学性质。使用这种聚硫代醚高分子为生胶通过二氧化锰硫化制备了一种聚硫代醚密封剂,研究了它的机械性能以及抗热空气老化性能。     

甲基笼型倍半硅氧烷/CE杂化复合材料的力学性能

以甲基笼型倍半硅氧烷(POSS)作为氰酸酯树脂(CE)的改性剂,制备出一种POSS/CE杂化复合材料。研究了杂化复合材料中POSS用量对CE结构及力学性能的影响,同时采用红外光谱(FT-IR)法对不同POSS/CE体系的反应性进行了研究。结果表明:POSS的加入对CE的反应性影响不大,有利于POSS/CE杂化体系固化工艺的制定;当杂化体系中w(POSS)=5%时,材料的冲击强度(9.7 kJ/m2)相对最大(提高了49%),弯曲强度(90 MPa)也相对较高,说明适量的POSS对CE具有明显的增韧、增强作用。     

ABA triblock copolymers containing polyhedral oligomeric silsesquioxane pendant groups: synthesis and unique properties

The synthesis and characterization of POSS containing ABA triblock copolymers is reported. The use of atom transfer radical polymerization (ATRP) enabled the preparation of well-defined model copolymers possessing a rubbery poly(n-butyl acrylate)(pBA) middle segment and glassy poly(3-(3,5,7,9,11,13,15-heptaisobutyl-pentacyclo[9.5.1.1^3,9.1^5,15.1^7,13]-octasiloxane-1-yl)propyl methacrylate(p(MA-POSS)) outer segments. By tuning the relative composition and degree of polymerization (DP) of the two segments, phase separated microstructures were formed in thin films of the copolymer. Specifically, dynamic mechanical analysis and transmission electron microscopy (TEM) observations reveal that for a small molar ratio of p(MA-POSS)/pBA (DP=6/481/6) no evidence of microphase separation is evident while a large ratio (10/201/10) reveals strong microphase separation. Surprisingly, the microphase-separated material exhibits a tensile modulus larger than expected (ca. 2×10⁸ Pa) for a continuous rubber phase for temperatures between a pBA-related T_g and a softening point for the p(MA-POSS)-rich phase. Transmission electron microscopy (TEM) images with selective staining for POSS revealed the formation of a morphology consisting of pBA cylinders in a continuous p(MA-POSS) phase. Thermal studies have revealed the existence of two clear glass transitions in the microphase-separated system with strong physical aging evident for annealing temperatures near the T_g of the higher T_g phase (p(MA-POSS). The observed aging is reflected in wide-angle X-ray scattering as the strengthening of a low-angle POSS-dominated scattering peak, suggesting some level of ordering during physical aging. The T_g of the POSS-rich phase observed in the microphase separated triblock copolymer was nearly 25 °C higher than that of a POSS-homopolymer of the same molecular weight, suggesting a strong confinement-based enhancement of T_g in this system.     

Synthesis and antimicrobial activity of quaternary ammonium-functionalized POSS (Q-POSS) and polysiloxane coatings containing Q-POSS

An array of quaternary ammonium-functionalized POSS (Q-POSS) compounds were synthesized and their antimicrobial properties toward the Gram-negative bacterium, Escherichia coli, and the Gram-positive bacterium, Staphylococcus aureus, determined in aqueous solution. Using Q-POSS compositions that exhibited broad spectrum antimicrobial activity in solution, the utility of the Q-POSS compounds as an antimicrobial additive for polysiloxane coatings was determined. The results of the investigation showed that Q-POSSs possessing a relatively low extent of quaternization and longer alkyl chain lengths provided the highest antimicrobial activity in solution. For polysiloxane coatings containing Q-POSS molecules as an antimicrobial additive, coating surface energy, surface morphology, and antimicrobial properties were found to be strongly dependent on Q-POSS composition. Coatings based on Q-POSSs possessing the lowest extent of quaternization displayed antimicrobial activity while analogous coatings produced using Q-POSSs possessing the highest extent of quaternization showed no antimicrobial activity. The lack of antimicrobial activity exhibited by coatings possessing Q-POSSs with a relatively high extent of quaternization was attributed to agglomeration of Q-POSS molecules through the formation of intermolecular interactions involving the quaternary ammonium moieties. Agglomeration would be expected to reduce diffusivity and inhibit interaction of the Q-POSS molecules with microbial cells.     

Synthesis,Morphology, and Viscoelastic Properties of Polyhedral Oligomeric Silsesquioxane Nanocomposites with Epoxy and Cyanate Ester Matrices

Octaaminophenyl(T₈)POSS [1, (C₆H₄NH₂)₈(SiO_1.5)₈] and dodecaaminophenyl(T₁₂)POSS [2, (C₆H₄NH₂)₁₂(SiO_1.5)₁₂] were synthesized, characterized and then incorporated into two types of thermoset resins: (1) the bisphenol-F-based cyanate ester resin, PT-15, and (2) epoxy (Epon 828, Shell Chemical Corp.)/4,4′-diaminodiphenylmethane (DDM) resin, respectively, to make two series of nanocomposites. The sum of amino groups in both DDM and POSS were held in a 1:1 mole ratio to the epoxy groups. EPON-828/1/DDM and EPON-828/2/DDM composites (78.63/0/21.37, 77.48/5/17.52, 76.34/10/13.66, 74.05/20/5.95 and 72.28/27.72/0 wt/wt/wt compositions for both series) were prepared. PT-15/1 and PT-15/2 composites (99/1, 97/3 and 95/5 wt/wt compositions for both types) were also prepared. These nanocomposites were characterized by transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), solvent extraction and FT-IR. In all systems, POSS 1 and 2 were chemically bound into the resin matrix and phase-separated POSS particle domains were not observed. Incorporation of both 1 and 2 can dramatically elevate the high temperature bending storage moduli, E′, of epoxy resins.