吡啶基三唑配合物催化下甲基丙烯酸甲酯的原子转移自由基聚合研究

以配体3,5-二-(4-吡啶基)-1,2,4-三唑与CuX形成催化剂,分别以α-溴代异丁酸乙酯和氯化苄为引发剂,环己酮为溶剂,进行了甲基丙烯酸甲酯(MMA)的原子转移自由基聚合(ATRP),同时考察了配比、溶剂量以及温度对聚合速率、聚合物分子量及分子量分布的影响.80℃下的聚合反应速度高于70℃;以环己酮为溶剂,单体与溶剂之比为1∶1.5时可得到较低分子量分布的聚合物.实验结果表明以吡啶基三唑为配合物催化甲基丙烯酸甲酯的聚合过程中,转化率和分子量随时间的增加而增大,聚合反应符合一级动力学规律,所得聚合物分子量分布较窄(1.21～1.46),结合端基分析和扩链反应结果,证明该聚合反应符合"活性"/可控自由基聚合.     

ACPDA／BPO引发苯乙烯聚合及其动力学

研究了4,4'-偶氮二[4-氰基戊酰(对-二甲基氨基)苯胺](ACPDA)/过氧化二苯甲酰(BPO)氧化还原引发体系在N,N-二甲基甲酰胺(DMF)中引发苯乙烯(St)的聚合及其动力学行为.考察了聚合反应温度、单体浓度、ACPDA浓度和BPO浓度对聚合物分子量和聚合反应速率的影响,测定了反应级数和聚合反应的活化能.实验结果表明:在一定范围内,聚合反应速率随单体浓度、ACPDA浓度、BPO浓度的增加和反应温度的升高而加快;聚合物分子量随单体浓度的增大而增大,随ACPDA浓度、BPO浓度的增大和反应温度的升高而降低.该体系具有氧化还原引发体系的特点,其聚合速率方程为Rp=K[St]1.52[ACPDA]0.56[BPO]0.49,聚合反应的表观活化能Ea =35.43 kJ/mol.     

甲醇存在下St-BA-HEA体系的无皂乳液聚合研究

在甲醇存在下 ,以苯乙烯 (St)和丙烯酸丁酯 (BA)为主单体、丙烯酸 -2 -羟乙酯(HEA)为功能单体 ,采用无皂乳液聚合技术 ,合成了聚合物微球。考察了助溶剂甲醇的用量、引发剂用量 ,以及丙烯酸 -2 -羟乙酯的用量对聚合反应速率、乳胶粒的粒径及单分散性的影响。试验结果表明 ,加入适量的甲醇可以加快聚合反应速率 ,增大乳胶粒的粒径 ,提高单分散性。另外 ,在一定量的甲醇存在下 ,增加引发剂以及丙烯酸-2 -羟乙酯的用量加快了反应速率 ,同时也使乳胶粒的粒径增大。     

负载型钛催化剂催化1-十二烯溶液聚合动力学

采用TiCl4/MgCl2-Al(i-Bu)3催化剂,溶液聚合法合成了聚1-十二烯烃油溶性减阻剂.使用Brookfield DVⅢ型流变仪对以正已烷、正庚烷和环已烷为溶剂的原料进行流变性研究,以此考察不同溶剂体系对聚合速率的影响,测定了主催化剂TiCl4/MgCl2浓度与助催化剂Al(i-Bu)3浓度的反应级数和聚合反应的表观活化能,并由此建立聚合反应速率方程,探讨了聚合速率对聚合物特性粘数的影响.结果表明,以正已烷、正庚烷和环已烷为溶剂时,聚合速率依次降低,但对单体浓度均呈一级反应;在本研究催化剂加量范围内,聚合速率对主催化剂浓度呈一级关系,而刘助催化剂浓度呈零级关系.聚合速率与特性粘数不成正比关系,需在合适聚合速率下才能得到较高特性粘数.在-5～5℃,聚合的表观活化能为56.64 kJ/mol.     

微悬浮聚合法合成聚醋酸乙烯酯的动力学研究

采用微悬浮法合成聚醋酸乙烯酯,对其聚合反应的动力学进行了研究。考察了引发剂浓度、乳化剂浓度、单体浓度以及温度对聚合反应速率的影响。结果表明,聚合反应速率对引发剂浓度、乳化剂浓度和单体浓度的反应级数分别为0．45,0．28,1．90,单体浓度对聚合反应速率的影响最大,反应体系的表观活化能为105．96 kJ/mol。     

紫外光引发甲基丙烯酸-N,N-二甲氨基乙酯溶液聚合的研究

研究了甲基丙烯酸 -N ,N -二甲氨基乙酯的紫外光引发自由基溶液聚合的条件 ,包括引发剂安息香乙醚用量、单体浓度、光引发时间及其对聚合速率、产率与相对分子质量的影响 ,实验确定了制备线型聚甲基丙烯酸 -N ,N -二甲氨基乙酯聚合物的工艺及方法。采用膨胀计法研究了聚合反应 ,其反应速率与单体浓度呈 1.91级关系 ,结果表明 ,单体可能同时参与了光引发过程     

水凝胶-水凝胶复合材料的制备与表征

将聚乙二醇400(PEG400)溶胀的交联N-乙烯吡咯烷酮(NVP)水凝胶微粒浸渍在含有引发剂过氧化苯甲酰(BPO)的甲基丙烯酸-2-羟基乙酯(HEMA)单体中并加热引发聚合反应,制备水凝胶-水凝胶复合材料,研究了产物的溶胀行为,并采用SEM、DSC对产物进行了表征。结果表明,水凝胶-水凝胶复合材料的饱和含水量随交联NVP水凝胶颗粒的含量及饱和含水量增大而增大,两种水凝胶之间的界面结构可分为包埋、部分互穿网络以及完全部分互穿网络等三种,其原因在于HEMA单体部分进入交联NVP水凝胶微粒并进行原位聚合的程度不同;处于分散相的水凝胶与处于连续相的水凝胶的吸水倍率不同,导致水凝胶-水凝胶复合材料吸水溶胀时不同相结构之间互相制约,处于分散相的水凝胶的大分子链不能充分伸展,非冻结水的熔融峰被自由水的熔融峰掩盖,表现为DSC谱图上非冻结水的熔融峰被自由水的熔融峰掩盖。     

硅水凝胶隐形眼镜材料的合成与性能研究

以甲基丙烯酸羟乙酯（HEMA）、N-乙烯基毗咯烷酮（NVP）和γ-（甲基丙烯酰氧）丙基三甲氧基硅烷（KH-570）为单体,以偶氮二异丁腈（AIBN）为引发剂,通过本体聚合反应合成新型硅水凝胶角膜接触镜.考察了各单体配比、反应温度等对聚合的影响.结果表明,当反应温度为90℃,反应时间为2h,V（HEMA）：V（NVP）：V（KH-570） =8∶ 1∶1时,合成的隐形眼镜透氧量（DK/t）达到64.0×10-9（cm3O2·cm）/（cm2·s·mmHg）,含水量38％,透光率95.5％以上.     

茚基钠/四氢呋喃体系引发丙烯腈聚合的研究

以茚基钠为引发剂,对丙烯腈在四氢呋喃中的聚合反应进行了研究,考察了引发剂用量、单体与溶剂配比、反应时间及反应温度对丙烯腈聚合的影响,并用粘度法对聚合产物的粘均分子量进行了表征.结果发现茚基钠/四氢呋喃体系对丙烯腈聚合反应具有一定的引发活性,且随着引发剂用量增加聚合反应转化率增大,聚合产物的粘均分子量下降;当单体用量一定时,溶剂的量越多,聚合反应的转化率越低,而聚合产物的粘均分子量却越大;反应时间在1 h之内,延长反应时间,转化率和粘均分子量都增大;反应温度对聚合反应转化率影响不大,但对聚合产物粘均分子量有明显影响.     

丙烯酰胺在离子液体中的聚合反应研究

以四氟硼酸1-丁基-3-甲基咪唑([bmim]BF4)离子液体为反应溶剂,以过氧化苯甲酰-N,N-二甲基苯胺氧化还原体系为引发剂引发聚合了丙烯酰胺。采用粘度法测定了聚丙烯酰胺的相对粘均分子量,考察了聚合反应时间、反应温度、引发剂浓度对聚合物分子量和聚合反应单体转化率的影响。结果表明,丙烯酰胺可以在[bmim]BF4离子液体中进行氧化还原聚合,聚合物分子量随反应温度的升高而下降,聚合反应速率随着温度的升高而升高,得到的聚丙烯酰胺分子量可高达7.32×107以上,且水溶性良好。     

Radiation-induced cationic polymerization of vinyl ethers in solution: 4. Polymerization of isopropyl vinyl ether in bulk and in various solvents

The influences of the polymerization media, the monomer and solvent concentrations and the temperature on the radiation-induced polymerization of isopropyl vinyl ether (IPVE) have been studied in detail under super-dry conditions. Rates of polymerization were measured and estimates of the rate constants of polymerization were calculated according to the simplified Hayashi-Williams equation. A comparison of the results with those previously reported for ethyl vinyl ether (EVE) is made. The much higher reactivity of IPVC in low polar solvents is interpreted by a drastic reduction of the polymer intramolecular solvation of the growing chain ends. This is ascribed to the bulkiness of the isopropyl side-chain groups. The radiation-induced polymerization of IPVE in bulk and in various solvents with different physical and solvating properties was studied. This was to obtain further information on the kinetics and the mechanisms involved with this monomer and also the role of the polymerization media. The influence of the monomer and solvent concentrations and of the polymerization temperature on the rate of polymerization have also been investigated.     

非极性混合介质中分散聚合法制备聚乙烯基吡咯烷酮

以乙烯基吡咯烷酮(NVP)为单体,环己烷的混合溶剂为分散介质,AIBN为引发剂,SEBS为分散剂,采用分散聚合的方法制备了分散性能好、粒径为1μm左右、热稳定性较好的聚乙烯基吡咯烷酮。考察了单体含量、引发剂用量、分散剂用量对分散聚合反应的影响。结果表明,转化率和分子量均随单体含量增加而增大,随引发剂的量的增大而减小;且在单体含量为30%、AIBN的用量为0.5%,分散剂用量为10%时,所合成的聚合物分子量最大。     

交联型单分散聚苯乙烯微球的制备

以聚乙烯吡咯烷酮（PVP）为分散剂，偶氮二异丁腈（AIBN）为引发剂，乙醇为分散介质，二乙烯基苯（DVB）为交联剂进行了苯乙烯（St）的分散聚合；讨论了引发剂、交联剂、分散剂、单体用量对聚合物粒径及分布的影响，制备了交联型单分散聚苯乙烯微球。实验表明：当交联剂质量分数达到单体质量分数的1％时，微球依然可以保持良好的单分散性。在聚合体系中引入抗坏血酸，使其与微量的氧结合，有效地提高了微球的均匀度。     

The synthesis of nonporous poly(isobutyl methacrylate) microspheres by suspension polymerization technique and investigation of their swelling properties

Poly(isobutyl methacrylate) (PiBMA) microspheres with different crosslinking densities were synthesized by suspension polymerization technique in aqueous medium and their characterization and swelling behaviors in different solvents were investigated. PiBMA spheres with a 800‐ to 1500‐μm‐diameter range were obtained by using benzoyl peroxide (BPO) as polymerization initiator, 1/5 ratio of monomer/water in volume, tricalcium phosphate (TCP), and poly(N vinyl‐2‐pyrrolidone) (PVP) as suspension stabilizer with 350 rpm stirring rate in nitrogen atmosphere. The influence of type and amount of crosslinking agent on the swelling properties and diffusional behavior, diffusion coefficient, and network properties of the spheres were examined in pentane, hexane, heptane, and gasoline. Dynamic swelling behaviors of crosslinked spheres were determined by measuring the diameter of the sphere as a function of time by an optical microscope. Swelling behaviors and network properties were found to be dependent on the diameter, crosslinking density of the sphere, and crosslinking agent and solvent. The results of this study indicate that the crosslinked PiBMA microsphere can be swollen in gasoline very well and retains a high ratio (1500% of its volume) of gasoline in their structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 349–356, 2002     

耐高温丙烯酸酯压敏胶的研制

以丙烯酸丁酯(BA)和丙烯酸-2-乙基己酯(2-EHA)为软单体、甲基丙烯酸甲酯(MMA)为硬单体、环氧树脂(EP)为改性单体、丙烯酰胺(AM)为内交联剂、过氧化苯甲酰(BPO)为引发剂以及乙酸乙酯/乙醇为混合溶剂,采用溶液聚合法制备出一种耐高温溶剂型丙烯酸酯PSA(压敏胶)。研究了单体、引发剂和交联剂等对PSA性能的影响。结果表明:当w(2-EHA)=20%、w(MMA)=13%、w(BPO)=0.5%和w(AM)=0.6%时,PSA的综合性能相对最好;当w(EP)=5%时,PSA的耐高温性能显著提高。     

高吸油树脂性能与再生的研究

采用悬浮聚合的方法合成一种交联适中的聚丙烯酸系高吸油性树脂。研究了单体组成及配比,引发剂用量和交联剂用量对树脂吸油性能的影响,并且对树脂的再生进行了研究。实验结果表明:当m(甲基丙烯酸十二酯):m(苯乙烯)为2:3,引发剂用量为单体质量的1%,交联剂用量为单体质量的1%时,吸油效果最为理想;通过乙醇溶剂萃取法进行再生脱油率可达92.3%。     

Highly crosslinked polymer particles by dispersion polymerization

Monodisperse poly(divinylbenzene) and poly(styrene-co-divinylbenzene) particles were prepared in the 0.4?3 μm size range by dispersion polymerization in methanol and methanol/co-solvent mixtures. The effects of polymerization parameters, such as the crosslinking monomer concentration, the co-solvent, and the presence of oxygen were studied. For good colloidal stability, it was necessary to use a relatively large fraction of crosslinking monomer. The initial presence of oxygen was also found to play an important role in determining the colloidal stability during the polymerization. Although the exact mechanism is not certain, it is considered likely that the oxygen promotes the grafting of poly(divinylbenzene) to the polyvinylpyrrolidone (PVP) stabilizer molecules. The growing particles were investigated by electron microscopy. Precipitation of small particles onto the nucleated particles was determined to be the primary mechanism of particle growth. © 1993 John Wiley & Sons, Inc.     

甲基丙烯酸甲酸-丙酸烯丁酯-丙烯酸三元溶液聚合研究Ⅰ.聚合速率影响因素的研究

本文系统研究了 Poly( MMA-BA-AA)聚合体系中溶剂的种类、含量 ,交联剂用量 ,引发剂用量 ,单体的配比 ,聚合温度对体系聚合速率的影响 ,绘制了各影响因素变化时的时间——转化率曲线     

Anionic ring‐opening polymerization of adipic anhydride initiated by potassium poly(ethylene glycol)ate

Poly(adipic anhydride) (PAA) was prepared by the ring‐opening polymerization of adipic anhydride (AA) initiated by potassium poly(ethylene glycol)ate. The effects of various factors, such as the amount of initiator, concentration of the monomer, reaction time and temperature, and polarity of the solvent on the polymerization were investigated. The crude polymerized product was a mixture of PAA homopolymer and poly(ethylene glycol)–poly(adipic anhydride) block copolymer, as confirmed by ¹H‐NMR and gel permeation chromatography. Chain‐transfer reactions occurred intensively for the AA polymerization in both the nonpolar solvent toluene and the polar solvents CHCl₃ and tetrahydrofuran, which predominantly determined the molecular weight and the monomer conversion for the polymerized product. The lower monomer conversion in toluene was ascribed to a lower livingness for the initiator in the nonpolar solvent when compared with other two, polar solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2194–2201, 2003     

Radical polymerization of acrylonitrile initiated by α-picolinium p-chlorophenacylid

The radical polymerization of acrylonitrile (AN) with α-picolinium p-chlorophenacylid (α-PCPY) as initiator using carbon tetrachloride as inert solvent was investigated at 50°C. The polymerization follows ideal kinetics: the exponent values calculated for the initiator and monomer were found to be 0.5 and unity, respectively. A free radical mechanism with bimolecular termination was confirmed by the inhibiting effect of hydroquinone, a radical quencher. The rate of polymerization was a direct function of initiator (α-PCPY) concentraction, monomer (AN) concentration and temperature. The overall activation energy calculated was 56 kJ/mol. The polymerization was favoured by polar solvents and retarded by non-polar solvents.