负载钛催化丁烯-1扩大溶液聚合反应过程

采用TiCl4/MgCl2-Al(i-Bu)3催化体系在10L聚合釜中用溶液法研究了丁烯-1聚合反应过程。结果表明,在反应温度为20℃条件下,聚合的速率方程为-d[Bt]/dt=41[Ti][Bt][PH2]0.4;在10～30℃,聚合的表观活化能为16kJ/mol;提高催化剂浓度、聚合温度、氢气压力能明显提高单体转化率、加快反应速率。     

TiCl4/SiO2负载型催化剂用于丁二烯聚合Ⅱ.聚合条件及聚合动力学

使用以球磨法制备的SiO2负载TiCl4催化剂进行丁二烯溶液聚合,考察了聚合条件对催化效率的影响以及在20～60℃下的聚合动力学.确定了适宜的聚合条件以加氢汽油为溶剂,Al/Ti摩尔比为20,Ti/Bd摩尔比为2×10-4,50℃聚合10h以上.溶液聚合动力学研究结果表明,本体系在低转化率下为稳态聚合,其稳态聚合速率方程为Rp=kpf[Ti]0[Bd],聚合的表观活化能为11.4kJ/mol.     

用稀土催化剂制备高顺式丁二烯-异戊二烯共聚物

以酸性膦酸酯钕Nd(P<,507>)<,3>(简称Nd)、氢化二异丁基铝(简称Al)、三氯甲烷(简称Cl)和三氯乙酸乙酯(简称ETCA)为催化体系,在环己烷溶剂中进行丁二烯/异戊二烯共聚合.考察了催化剂组成、陈化温度和时间及聚合温度等对聚合过程的影响.结果表明,在[Al]/[Nd]为20、[Cl]/[Nd]为10、[E...     

钴系催化剂催化异戊二烯的本体聚合

以环烷酸钴(简称Co)-三异丁基铝(简称Al)-CS2为催化剂引发异戊二烯(Ip)本体聚合合成了聚异戊二烯(PI),考察了单体转化率、催化剂效率(CE)和聚合物特性黏数([η])的影响因素,并对PI的微观结构和玻璃化转变温度(Tg)进行了表征。结果表明,在Co/Ip(摩尔比)为4.0×10-4、Al/Co(摩尔比)为60、CS2/Co(摩尔比)为15、反应温度为50℃下聚合48 h所得PI中1,4-结构、3,4-结构、1,2-结构质量分数分别为18.6%,41.2%,40.2%,Tg为-6.5℃;反应温度对PI的[η]影响最大,随着反应温度的升高,[η]呈下降趋势,且均小于1 dL/g;其他聚合条件的变化对PI的[η]影响不大。     

TiCl4/SiO2负载型催化剂用于丁二烯聚合Ⅱ.聚合条件及聚合动力学

使用以球磨法制备的 SiO2负载 TiCl4催化剂进行丁二烯溶液聚合，考察了聚合条件对催化效率的影响以及在 20～ 60℃下的聚合动力学。确定了适宜的聚合条件：以加氢汽油为溶剂， Al/Ti摩尔比为 20, Ti/Bd摩尔比为 2× 10－ 4, 50℃聚合 10 h以上。溶液聚合动力学研究结果表明，本体系在低转化率下为稳态聚合，其稳态聚合速率方程为 Rp=kpf[Ti]0[Bd],聚合的表观活化能为 11.4 kJ/mol。     

PMMA-[BMIM]PF_6-非质子溶剂复合型凝胶电解质的制备和性能

采用烯类单体MMA在离子液体[BMIM]PF6和PC、DMC等形成的混合溶液中聚合,合成一系列PMMA-[BMIM]PF6-非质子溶剂复合型凝胶电解质,并对其性能进行了研究。结果表明,当m([BMIM]PF6)∶m(PC)=45∶55时,凝胶电解质PMMA-PC-[BMIM]PF6的室温电导率值为3.44×10-3S/cm,当m([BMIM]PF6)∶m(DMC-PC)=35∶65时,PMMA-LiPF6-(PC-DMC)-[BMIM]PF6的室温电导率值为10.05×10-3S/cm,并随温度升高而增加,变化规律符合VTF方程。凝胶电解质热分解温度都在250℃以上,在80℃时热失重小于0.97%。锂离子的迁移数约为0.3。电化学窗口高达5.1V。     

三异丁基铝阻滞苯乙烯负离子聚合动力学

以环己烷为溶剂、三异丁基铝为阻滞剂、丁基锂为引发剂,研究了三异丁基铝与丁基锂摩尔比[n（Al）/n（Li）]和聚合温度对苯乙烯阻滞负离子聚合反应速率和动力学的影响规律,对相应的假一级表观增长速率常数进行了求解。结果表明,采用三异丁基铝/丁基锂体系引发苯乙烯阻滞负离子聚合,在苯乙烯转化率较低（小于60%）时,苯乙烯聚合速率对单体浓度为一级动力学关系;随着n（Al）/n（Li）的增大,苯乙烯聚合速率下降;n（Al）/n（Li）越接近1,阻滞效果越明显。聚合温度对三异丁基铝/丁基锂体系引发苯乙烯阻滞负离子聚合速率有显著影响,随着温度升高,聚合速率上升,阻滞效果变差;温度每升高10 ℃,苯乙烯聚合速率增大约1倍。聚合温度和n（Al）/n（Li）存在叠加影响,而前者对不同n（Al）/n（Li）引发体系的影响程度存在差异;聚合温度较低时,其变化对聚合速率影响更大。     

可聚合型离子液体乳化剂的性能及在SAN合成中的应用

甲基丙烯酸二甲氨基乙酯与溴代烷烃反应合成可聚合离子液体——甲基丙烯酸二甲氨基乙酯丁基溴盐([DMC4]Br)、甲基丙烯酸二甲氨基乙酯癸基溴盐([DMC10]Br)、双甲基丙烯酸二甲氨基乙酯丁基溴盐([DM-C4-DM]Br2)和双甲基丙烯酸二甲氨基乙酯癸基溴盐([DM-C10-DM]Br2)。采用1HNMR和FTIR对其结构进行了表征。用电导率法测得其临界胶束浓度分别为16.20、11.20、25.61和16.13 mmol/L。分别以[DMC10]Br、[DM-C10-DM]Br2和十二烷基磺酸钠(SDS)为乳化剂制备了苯乙烯-丙烯腈共聚物(SAN);当[DM-C10-DM]Br2添加量(以单体总质量计,下同)为4%时,所制备的SAN单体转化率为90.2%;粒径为320.3 nm;SAN主链热分解起始温度为353℃;制备后废水的化学需氧量(COD)为937mg/L。该乳化剂制备的SAN的主链热分解温度比SDS制备的SAN提高了22℃,废水COD降低了1512 mg/L。     

希夫碱锌金属配合物催化ε-己内酯开环聚合的研究

以希夫碱锌金属配合物[LZn]为催化剂,催化ε-己内酯开环聚合。以甲苯为溶剂,采用[LZn]为主催化剂,4-二甲氨基吡啶为助催化剂,聚合温度为80℃,反应6h,氮气保护下进行聚合反应,获得的聚ε-己内酯数均分子量Mn为24. 653×103g·mol-1,分子量分布为1. 21。实验结果表明,该希夫碱锌金属配合物[LZn]能够实现ε-己内酯开环聚合,聚合效果较好,产物分子量分布较窄。     

PNB/nano-SiO_2复合材料的制备与性能

制备了纳米二氧化硅(nano-SiO_2)负载乙酰丙酮二氯化钯催化剂(记作负载钯催化剂),并以三五氟苯硼[B(C_6F_5)_3]为助催化剂,通过一步原位聚合法制备了聚降冰片烯/nano-SiO_2(PNB/nano-SiO_2)复合材料。通过改变聚合工艺,实现对聚合行为的调控。结果表明:当负载钯催化剂为10μmol,B(C_6F_5)_3为0.20 mmol,聚合温度为60℃,聚合物活性为1.02×10~6 g_(PNB)/(mol_(Pd)·h)时,PNB/nano-SiO_2复合材料中的SiO_2粒子分散良好、分布较均匀,体系相容性较好。制备的PNB/nano-SiO_2薄膜拉伸强度随着SiO_2含量增加而提高,且透明性较好。     

In-situ IR Monitoring the Synthesis of Amphiphilic Copolymery P(HEMA-co-tBMA) via ARGET ATRP

The amphiphilic copolymer poly(hydroxyethyl methacrylate-co-tert-butyl methacrylate) [P(HEMA-co-tBMA)] was synthesized by activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), with the synthesis process monitored by in-situ infrared spectroscopy (IR). The molecular weight, chemical structure and characteristics of the copolymer were determined by 1H NMR, gas chromatography and gel permeation chromatography. The influences of various parameters on the living polymerization were explored. The molecularweight of the copolymer with narrowmolecularweight distribution (M_w/M_n b 1.50) increases approximately linearly with the monomer conversion, indicating a good control of polymerization. In the reaction temperature range from 50℃ to 90℃, the monomer conversion is higher at 60℃. The tBMA conversion rate decreases gradually with the increase of tBMA content, while the HEMA conversion is hardly affected by HEMA content. Weak polar solvent is more favorable to the polymerization compared to polar solvent. The molar ratio of reducing agent to catalyst has significant effect on the polymerization and increasing the amount of reducing agent will accelerate the reaction rate but causes wider molecular weight distribution. It is indicated that in-situ IR monitoring contributes to a more in-depth understanding of the mechanism of methacrylate monomer copolymerization.     

乳液聚合成核阶段的模拟与分析

建立了乳液聚合成核阶段的Monte Carlo模型，并用计算机对一个体积为10^-17m^3的微型反应器中苯乙烯的乳液聚合进行了模拟。以计算机生成随机数作为自由基被胶束和乳胶粒捕获的几率，模拟了在微型反应器中每一个自由基的生成、被胶束或乳胶粒捕获的过程以及每一个乳胶粒的生成及增长过程。通过对每一个乳胶粒在增长过程中各参数的统计计算，研究了乳液聚合成核阶段诸参数(乳胶粒数目、乳胶粒直径与粒径分布、单体转化率、聚合反应速率等)与乳化剂浓度[S]及引发剂浓度[I]的关系。结果表明，苯乙烯的乳液聚合体系中乳胶粒数目与[S]^0.5996[I]^0.4016成正比：在成核阶段乳胶粒直径分布先变宽后变窄，乳液聚合过程中乳胶粒直径分布有自动变窄的趋势；成核阶段持续时间t12与[S]^0.60[I]^0.60成正比，成核阶段结束时的单体转化率X12与[S]^1.20[I]^0.20成正比。     

用于可再分散乳胶粉的阳离子苯丙乳液的合成

采用种子乳液聚合法,以十六烷基三甲基溴化铵(CTAB)为乳化剂,偶氮二异丁眯盐酸盐(AIBA)为引发剂,引入亲水性阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)及功能性单体丙烯酰胺(AM)〔m(DMC)∶m(AM)=1∶1〕来制备用于可再分散乳胶粉的阳离子苯丙乳液。探讨了聚合反应温度、乳化剂用量、引发剂用量、种子单体用量、阳离子单体用量等对乳液及可再分散乳胶粉性能的影响。确定最佳配方和工艺条件为:聚合反应温度为(80±2)℃、DMC添加量为2%(以主要聚合单体质量计,下同)、CTAB用量为2%(以单体总质量计,下同)、AIBA用量为0.53%(以单体总质量计,下同)、种子单体用量为10.0%(以单体总质量计,下同)。在该工艺条件下,合成的阳离子苯丙乳液粒径大小和分布适中、性能稳定,由其所制得的可再分散乳胶粉含水率低、平均粒径小、再分散性优良。     

Template polymerization of dimethylaminoethylmethacrylate in the presence of polyacrylic acid

The occurrence of a template process in the system polyacrylic acid (PAA) as the template for the polymerization of dimethylaminoethylmethacrylate (DMAEM) has been deduced from kinetic observations. Radical photopolymerization was carried out in aqueous acetone solution (1:2 v/v) using azobisisobutyronitrile (AIBN, 1 x 10-3 mol litre-1) as the radical initiator. Polymerizations were carried out using different concentration ratios of template [T] to monomer [M]. All runs were performed in evacuated dilatometers. The rate of polymerization increased in the presence of the polymer catalyst and was found to attain a maximum value at a ratio of [T]/[M] of about 1.5 in the presence of UV light of λ = 365 nm and at a temperature of 25 /pm 0.05°C. Partial separation of the PAA from the daughter polymer PDMAEM has been achieved.     

乙酸乙烯酯无乳化剂乳液聚合的影响因素探讨

采用乙酸乙烯酯(VAc)在水中以过硫酸钾(KPS)和亚硫酸氢钠氧化还原体系作为引发剂进行无乳化剂乳液聚合,探讨了引发剂浓度、聚合温度、单体浓度和搅拌速度对聚合速率及转化率的影响。结果表明:当VAc质量分数为30%,KPS:VAc摩尔比为1:2 000,聚合温度10℃,反应时间10 h,搅拌速度80 r/min,时聚合产物聚乙酸乙烯的聚合度达到10 848;当VAc质量分数为35%时,聚合转化率可达到96%,聚合速率与引发剂浓度的0.944次方成正比;当搅拌速度达到200 r/min以上时,搅拌速度对聚合速率以及转化率影的响可以忽略。     

Preparation and Characterization of UHMWPE/Graphene Nanocomposites Using Bi-Supported Ziegler-Natta Polymerization

Ultrahigh-molecular-weight polyethylene (UHMWPE)/graphene nanocomposites with molecular weights as high as 3 × 10⁶ g/mol were prepared via in situ polymerization using a bi-supported Ziegler-Natta catalytic system. Effects of [Al]/[Ti] molar ratio, temperature, monomer pressure, and polymerization time on productivity of the catalyst have been investigated. Increasing [Al]/[Ti] molar ratio from 128 to 320, increased productivity from 1667 g PE/mmol Ti.h to maximum value which was 2420 g PE/mmol Ti.h. Further [Al]/[Ti] ratio decreased the productivity. Reaction temperature effect investigation reveals that the optimal activity was obtained at 60°C. the polymerization productivity increases with monomer pressure and decreased with polymerization time. Morphological information was determined by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Obtained results show that graphene layers in these nanocomposites were completely exfoliated and dispersed uniformly in the polyethylene matrix while no nanoparticle cluster has been formed.     

Online monitoring of reaction temperature during cationic ring opening polymerization of epichlorohydrin in presence of BF3 and 1,4‐butanediol

This work introduces cationic ring opening polymerization of polyepichlorohydrin (PECH) produced under various reaction conditions (set temperature: ?10 to 40°C, [C]/[I] ratio: 0.1–1, monomer feed rate: 1–4 mL/min). In addition, a correlation between the exothermic reaction temperature and the performance of the PECH was obtained by utilizing a reaction temperature monitoring system, GPC, ¹H‐NMR, and FTIR. During the polymerization, an induction period which affects the polydispersity was observed below 10°C. At lower temperatures and lower [C]/[I] ratios, a higher induction period was observed. The monomer feed rate did not affect the induction period but it highly affected the polydispersity when the induction period occurred. The total molecular weight of PECH increased with decreasing set temperature even though the amount of low molecular weight cyclic oligomer increased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39912.     

Peroxo salts as initiators of vinyl polymerization: Polymerization of acrolein initiated by potassium peroxodiphosphate

Kinetic studies were made on the polymerization of acrolein initated by potassium peroxodiphosphate (PP) in aqueous solution, in the presence and absence of Ag⁺ ions. The rate of polymerization was found to depend on [M]^3/2 (M = monomer) and was independent of both [PP] and [Ag⁺]. The overall activation energy was calculated to be 4.8 kcal mol⁻¹. A mechanism involving termination by PO^2-₄ radicals is proposed and discussed.     

一种有机-无机清水剂的合成与应用

采用自由基聚合法合成了一种新型有机-无机清水剂。考察了单体丙烯酰胺和二甲基二烯丙基氯化铵总浓度、稳定剂W浓度、引发剂用量、反应温度、搅拌速度对合成的影响。结果表明,最佳实验条件为:单体丙烯酰胺和二甲基二丙烯基三甲基氯化铵总浓度15%,稳定剂W浓度10%,引发剂浓度0.4 mmol/L[(NH4)2S2O8与NaHSO3的摩尔比为1∶2],反应温度45℃,搅拌速度150 r/min。同时,在油田现场应用,很少的用量就能达到很好的脱水和清水效果。