SYNTHESIS OF MACROPOROUS COPOLYMER OF VCA AND DVB

The reactivity ratios of vinyl acetate(VAc) and divinyl benzene (DVB) were calculated from the Q and e values.The possibility of the copolymerization of these two monomers was predicted and the copolymerization was carried out by suspension polymerization technique in the presence of pore producing agent (toluene and gasoine).The relative ratio of acetoxy group and benzene ring in the copolymer were monitored by IR measurement during the polymerization.The variation of pore properties,such as spectific surface area,porosity and average pore diameter,with polymerization time were determined.The copolymers at various polymerization time were alcoholyzed and thus the variation of the hydroxyl group content with polymerization time was studied.     

醋酸乙烯—二乙烯基苯共聚反应动力学

根据文献查得的Ｑ，ｅ值，计算了醋酸乙烯－二乙烯基二元共聚的竞聚率，预测其共聚的可能性。以甲苯为汽油为致孔剂，采用悬浮聚合方法合成该二元大孔共聚物。红外光谱分析跟踪共聚反应过程中乙酰氧基和苯环相对比例的变化，并测定共聚反应过程中比表面积，孔率和平均孔径的变化。     

甲基丙烯酸羟乙酯(HEMA)共聚和均聚球状珠体的制备

本文研究了甲基丙烯酸羟乙酯均聚和共聚制备珠体的途径及影响因素,提出了一种针对极性单体的新的悬浮聚合方法;并探讨了聚合物珠体粒度分布的影响因素。研究发现,二乙烯基苯在甲基丙烯酸羟乙酯共聚反应中的用量会影响聚合反应的成败。     

SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP*

Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graftpolymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles throughcondensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated bythis surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silicananoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence ofATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases withpolymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation ofpolymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.     

用含偶氮基的聚苯乙烯大分子引发剂合成两亲性嵌段共聚物

采用含偶氮基的聚苯乙烯预聚物（ＰＳ ＡＣＰＣ）作为引发剂，合成了苯乙烯（Ｓｔ）分别与甲基丙烯酸（ＭＡＡ）、甲基丙烯酸（β 羟丙酯）（ＨＰＭＡ）的嵌段共聚物，考察了ＰＳ ＡＣＰＣ引发第二单体的聚合反应行为，以及影响第二单体转化率和均聚物含量、共聚物组成的因素．用溶解性、凝胶渗透色谱（ＧＰＣ）、红外光谱（ＩＲ）、核磁共振（ＮＭＲ）、动态接触角（ＤＣＡ）等表征了嵌段共聚物．     

Preparation of polymeric microspheres with high content of sulphonate groups

<正>Poly(styrene-co-sodium styrene sulphonate)(P(St-NaSS)) latex particles were prepared using the mixture of ethanol and water as continuous phase in the presence of surfactant by dispersion--emulsion combined polymerization.The influence of recipes on polymerization process as well as the content of sulphonate group in the purified products was investigated.Results showed that the copolymerization could be performed smoothly.When the mole ratio of NaSS/St/divinyl benzene(DVB) was 25/75/2 and the weight ratio of ethanol/water was 2/11,the product showed a low weight loss in methanol extraction purification,and the NaSS unit ratio in the purified product reached 20.6 mol%,which was close to its theoretical value of 24.9 mol%.     

稀土络合催化苯乙烯均聚及其与二乙烯苯共聚

应用稀土化合物:环烷酸钕Nd(naph)_3和二(2-乙基己基)磷酸钕Nd·(P_(204)_3分别与三异丁基铝Al(i-Bu)_3组成络合催化剂引发苯乙烯均聚及其与二乙烯苯共聚。适宜的聚合温度为50℃:[Nd]=3×10~(-5)mol/ml;[M]=3×10~(-3)mol/ml;Al/Nd=10(摩尔比),并且催化剂按以下次序配制:钕化合物→溶剂→苯乙烯→三异丁基铝,苯乙烯的转化率在90％以上。溶剂种类及聚合条件不同,制得的聚苯乙烯可为白色或黄色粉末状无定形聚合物,分子量几百至上万。聚合体系中添加PeCl_3能抑制黄色产生。在共聚反应中,二乙烯苯比苯乙烯显示较高的反应活性。     

Studies on polymers containing functional groups. II. Polymerization behavior of o-hydroxystyrene

The polymerization behavior of o-hydroxystyrene with free-radical and cationic initiators and without an initiator was examined. The structures thus obtained were estimated. Although polymerization behavior of o-hydroxystyrene was rather complicated, according to the results, it appeared that each polymerization more or less might simultaneously follow the two types of mechanisms: normal vinyl polymerization and polymerization through the addition to benzene nuclei. The proportion of addition to benzene nuclei was considered to be highest in the polymerization with BF₃·(OEt)₂ and lowest in that with azobisisobutyronitrile. Degrees of polymerization of these polymers were low in all cases (42–82). Some brief experiments on copolymerization of o-hydroxystyrene were carried out.     

乙烯基单体与含氮氧稳定自由基单体的原子转移自由基共聚合研究

通过苯乙烯或甲基丙烯酸甲酯与含氮氧稳定自由基的单体进行原子转移自由基共聚合 ,研究了共聚合反应的条件及动力学 ,成功地合成出侧链含TEMPO基团的氮氧稳定自由基聚合大分子引发剂 .大分子引发剂的结构通过核磁共振谱图进行确证 ,并对共聚合反应的历程进行了探讨     

Anionic Polymerization and Copolymerization of Hydrocarbon Monomers Catalyzed by Organobarium Initiators

The barium salt of the dimeric dianion of 1,1-diphenylethylene (Ba-DPhE) initiates polymerization and copolymerization of monomers capable of anionic polymerization (butadiene, isoprene, styrene) in ethereal and hydrocarbon solvents. Ba-DPhE is more stereospecific in butadiene polymerization (up to 70% of cis-1, 4-units in hydrocarbon medium) than initiators based on other metals of Groups I and II. The relative reactivity of monomers in copolymerization processes in THF decreases in an order typical for anionic polymerization: styrene > butadiene > isoprene. The most interesting feature of organobarium initiators is their ability to form random butadiene-styrene copolymers with high cis-1,4-butadiene unit content when copolymerization proceeds in a hydrocarbon medium.

A new phenomenon in anionic polymerization, the dependence of diene units structure on copolymer composition, was observed. Thus an increase of styrene content in butadienestyrene copolymer leads to conversion of cis-1,4-butadiene units into trans-1,4-units (in benzene) or to conversion of 1,4-units to 1,2-units (in THF). Similarly, an increase of butadiene content in its copolymer with isoprene (in benzene) leads to conversion of cis-1,4-isoprene units into trans-1,4-units.

Spectrophotometric, conductometric, and viscometric methods were used to study organobarium active centers. Certain anomalies connected with the formation of specific aggregates due to coupling of bifunctional hydrocarbon chains with bivalent counterions were observed.     

Preparation of multihollow P(St-MAA) particles by sequence soap-free/soap emulsion polymerization and followed by stepwise alkali/acid posttreatment

The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization.     

铁系催化剂催化降冰片烯与丙烯酸甲酯共聚合

研究了Fe(acac)3-Al(i-Bu)3(acac=乙酰丙酮)催化降冰片烯(NB)与丙烯酸甲酯(MA)共聚反应条件影响、第三组份影响及催化剂铁铝比影响.并用核磁共振、红外光谱和元素分析方法研究了共聚物的组成,用热分析方法研究了共聚物的分解温度,并用电镜分析了共聚物的膜结构.结果表明,铁系催化剂在温和的反应条件下有较好的催化性能,并可获得能够形成有序多孔膜的共聚物.     

Radical copolymerization of acrylic monomers. VI. Copolymerization of methyl methacrylate with methyl α-benzylacrylate

Free-radical copolymerization of methyl methacrylate and methyl α-benzylacrylate has been studied in benzene solutions at 40 and 60°C. A simple copolymerization model fits the composition data at both temperatures. However, considering that the ceiling temperature for the polymerization of methyl α-benzylacrylate in benzene solution (|M| = 5 mol/L) is 67°C and that the overall rate of copolymerization drastically decreases with respect to that of methyl methacrylate homopolymerization with an increase of the molar fraction of methyl α-benzylacrylate in the feed, the behavior of this system is analyzed from both simple and reversible copolymerization models.     

Functionalized polymer particles for chiral separation

The synthetic chiral polymer poly(N-acryloyl-S-phenylalanine ethyl ester) was immobilized by grafting to macroporous polymer particles of various composition and structure in a process involving copolymerization of the chiral monomer with residual double bonds present in the macroporous support particles. The support particles were prepared by suspension or micro- suspension polymerization of trimethylolpropane trimethacrylate (TRIM), divinylbenzene or by copolymerization of styrene and TRIM. The maximum amount of immobilized chiral polymer and the mechanical properties of the resulting materials varied with the swelling capacity of the parent support particles. Up to 60% (w/w) of chiral polymer could be immobilized to the pore system of highly cross-linked TRIM particles. The enantioselectivity of the chiral stationary phases increased with increase in the amount of immobilized chiral polymer. The results of studies of porosity and particle size variation during grafting form the basis for a discussion of the structure of the final materials.     

以聚苯乙烯为把的聚四氢呋喃(PTHF)梳型聚合物的制备

高分子的自组装已成为当今高分子科学的热门研究课题之一[1] .开展该研究工作 ,首先要获得特定结构的聚合物 .我们设计合成如图 1所示的梳型聚合物 ,调节制备Ａ ,Ｂ ,Ｃ三链段所用的单体和它们的聚合度等参数 ,并进一步进行自组装研究 .若Ａ段是结晶聚合物 ,且熔融温度低于Ｃ段的玻璃化转变温度 ,则在定型储能材料等方面具有应用前景 .合成梳型嵌段聚合物有三个方法 ,即发散 (Ｇｒａｆｔｆｒｏｍ) ,收敛 (Ｇｒａｆｔｔｏ)和大分子方法 .采用大分子技术 ,每个梳型链长及支化密度可控 ,一直是人们青睐的方法[2 ] .一般采用与普通烯类单体共聚…     

耐热性星形甲基丙烯酸甲酯共聚物的合成

195 6年 ,Swarzc等 [1,2 ] 报道了一种没有链转移和链终止的阴离子聚合技术 ,提出了“活性”聚合的概念 . 1 995年王锦山等 [3]发现和提出原子转移自由基聚合 ( ATRP)以来 ,活性自由基聚合就成了高分子合成领域的研究热点 ,并合成出各类指定结构的聚合物 [4～ 12 ] .具有环状结构的 N -环己基马来酰亚胺 ( NCMI)被广泛地用于与甲基丙烯酸甲酯 ( MMA)自由基共聚合制备耐热性有机透明材料 [13,14 ] ,但NCMI的引入将降低聚合物的加工流动性 ,若能利用多官能团引发剂如四溴甲基苯实现含 NCMI单体结构的可控 ATRP共聚合 ,合成出星形耐…     

Initiator‐fragment incorporation radical polymerization of divinylbenzene in the presence of glyoxylic oxime ether: Formation of soluble hyperbranched polymer

The copolymerization of divinylbenzene (DVB) and ethylstyrene (EtSt) was carried out at 70 and 80 °C in benzene with dimethyl 2,2‐azobisisobutyrate (MAIB) at high concentrations as initiator in the presence of methyl benzyloxyiminoacetate (MBOIA), a glyoxylic oxime ether, as a retarder. The copolymerization system of DVB (0.25 mol/L), EtSt (0.25 mol/L), MBOIA (0.5 mol/L), and MAIB (0.5 mol/L) gave benzene‐soluble copolymers despite a considerably high concentration of DVB as an excellent crosslinker. The yield and molecular weight of the resulting copolymers increased with time both at 70 and 80 °C and then leveled off because of initiator consumption. The homogeneous polymerization system involved electron spin resonance (ESR), observable nitrogen‐centered polymer radicals (MBOIA·) under the actual polymerization conditions. The MBOIA· concentration increased with time despite a homogeneous polymerization system, suggesting the formation of rigid hyperbranched polymers. A benzene solution of isolated copolymer also showed an ESR signal. The copolymer was soluble in acetone, toluene, chloroform, ethyl acetate, tetrahydrofuran, and N,N‐dimethylformamide but insoluble in n‐hexane, methanol, and dimethyl sulfoxide. MAIB fragments as high as 30–40 mol % were incorporated into the copolymers through initiation and primary radical termination, on the basis of which this polymerization was named the initiator‐fragment incorporation radical polymerization. MBOIA (13–16 mol%) was also incorporated into the copolymers through an opening of the C?N bond. The intrinsic viscosity of the copolymers was very low (0.08 dL/g), and the reduced viscosity was almost independent of the polymer concentration, supporting a hyperbranched structure of them. Gel permeation chromatography and multi‐angle laser light scattering and transmission electron microscopy revealed that the copolymer was formed as a hyperbranched nanoparticle. The thermal behavior of the copolymer was examined by dynamic thermogravimetry and differential scanning calorimetry. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3038–3047, 2003     

苯乙烯/二乙烯基苯在乙醇/乙二醇单甲醚中分散共聚合速率及粒子大小的研究

以乙醇 乙二醇单甲醚 (EOH EGME)为介质 ,羟丙基纤维素 (HPC)为稳定剂 ,偶氮二异丁腈 (AIBN)为引发剂进行了苯乙烯和二乙烯基苯的分散共聚合研究 .制得粒径在 6～ 10 μm范围内的单分散交联聚苯乙烯微球 (CPS) .探讨了不同介质配比 ,以及苯乙烯、二乙烯基苯、引发剂的浓度对微球大小、粒径分布、聚合速率及稳定性的影响 .当苯乙烯和AIBN浓度增加时 ,聚合速率和平均粒子尺寸增加 ,而粒子分布变宽 ,粒子数先增加 ,而后降低 .随着EOH EGME比例的增加 ,平均粒子尺寸增加 ,而分布指数降低 ,稳定剂增加 ,粒子尺寸降低和粒子数增加 ,但对聚合速率及粒子分布影响不太明显 .另外还探讨了单体和交联剂的后滴加法对微球大小、粒径分布的影响     

Preparation of a novel hybrid organic-inorganic monolith for the separation of lysozyme by high performance liquid chromatography

A novel hybrid organic-inorganic monolith for high performance liquid chromatography (HPLC) was firstly developed by atom transfer radical polymerization (ATRP) by a simple and rapid method, in which vinyl ester resin was used as the monomer, natrium bisulfurosum was used both as organic adjunct and coadunate initiator to alter the activity of the free radical in the process of polymerization and then to control the molecular mass. The conditions of polymerization were optimized. The chemical group of the monolith was assayed by infrared spectra method, the morphology of monolithic material was studied by scanning electron microscopy (SEM) and the pore size distribution was determined by a mercury porosimeter. Finally, the monolith was used to separate lysozyme (Lys) from chicken egg white with good resolution and reproducibility that were obtained in a short time (10 min) by HPLC. In addition, the influences of buffer concentration and pH value on elution have been investigated and the hybrid monolith was used to separate benzene and its homologs from the mixture.     

AM/AMPS共聚物光化学改性

水溶性高分子AM/AMPS系由丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)组成.本文应用光化学方法对AM/AMPS共聚物进行改性,得到活性可聚合产物.应用这种方法,在高分子链上生成的过氧化物含量随UV光照时间有明显变化,照射5-10 min过氧化物含量最高.值得指出,较高的过氧化物生成量仅在采用二苯酮作为光敏剂和保持低温的条件下才能得到.这种活性改性AM/AMPS共聚物,可用光聚合或热聚合方法引发不同烯类单体共聚合,得到不同用途的接枝/交联共聚物产品.