聚合条件对P（AN-co—IA）分子质量分布影响的研究

采用凝胶色谱（GPC）法测定了丙烯腈与衣康酸共聚物P（AN—co—IA）的重均分子质量和数均分子质量,并通过已知聚丙烯腈的重均分子质量数据和数均分子质量数据对所测的分子质量进行校正,进一步计算得到共聚物的多分散系数。同时研究了引发剂用量、单体浓度、聚合温度、聚合时间对P（AN—co—IA）分子质量分布的影响。研究结果表明,P（AN-co-IA）分子质量分布随引发剂用量的增大、聚合单体浓度的增加而变宽,与聚合反应温度、聚合反应时间无明显的变化趋势。     

过硫酸铵引发丙烯腈/衣康酸铵共聚合研究

为了合成高分子量的聚丙烯腈(PAN),选择衣康酸铵[(NH4)2IA]作为共聚单体,以过硫酸铵[(NH4)2S2O8]作为引发剂,采用水相沉淀聚合工艺,研究了单体配比对聚合反应的影响。利用元素分析、热分析和红外光谱研究了不同单体配比条件下共聚物的氧摩尔分数、热性能和结构特征。结果表明,水相沉淀聚合反应速率较快,且制得了粘均分子量高达58.46×104,(NH4)2IA的摩尔分数高达11.925%的聚丙烯腈共聚物;单体配比对共聚物的热性能有较大影响;红外光谱中有N—H键和羰基C＝O的伸缩振动,表明聚合物链中有(NH4)2IA存在。     

衣康酸/苯乙烯磺酸/丙烯酸共聚物阻垢剂的合成研究

以衣康酸(IA)、苯乙烯磺酸(SSA)和丙烯酸(AA)为单体,过硫酸铵为引发剂,异丙醇为链转移剂,在水相中合成了IA/SSA/AA共聚物阻垢剂.通过正交试验确立了最佳合成工艺条件:单体质量比m(IA):m(SSA):m(AA)=2:1:4,引发剂与总单体的质量比为4.5%,链转移剂与总单体质量比为9.5%,在95℃下反应2 h.当IA/SSA/AA共聚物的极限黏数为5.5～6.0 mL/g,实验水中Ca2 的质量浓度为1.6g/L,阻垢剂投加质量浓度为10 mg/L时,共聚物阻CaCO3垢的阻垢率高达91.9%,特别适用于高矿化度的工业循环冷却水和油田回注水.     

丙烯腈/丙烯酸甲酯/衣康酸三元共聚物序列结构的Monte Carlo模拟

以丙烯腈(AN)、丙烯酸甲酯(MA)、衣康酸(IA)为共聚单体,合成碳纤维用聚丙烯腈原丝的三元共聚物,利用Monte Carlo法模拟了AN／MA／IA三元共聚物的组成和序列结构,讨论了共聚单体对共聚物分子链序列结构的影响,探讨了增加序列结构均匀性的方案。结果表明:Monte Carlo法可以较为准确的模拟该共聚物的序列结构;AN／MA／IA以98／0.7／1.3的单体配比可以得到序列结构比较理想的共聚物;采取分批加入IA的方法,使共聚物的序列结构均匀性得到提高。     

合成中等分子质量聚丙烯腈聚合反应的研究

以NaClO_3/NaS_2O_5为氧化—还原引发剂,进行了丙烯腈(AN)与衣康酸(ITA)等几种不同单体的的水相沉淀聚合,制得了中等分子质量的聚丙烯腈(PAN)聚合体。系统地考察了引发剂浓度及配比、聚合温度、聚合时间、单体浓度以及第三单体甲基丙烯磺酸钠(MAS)的加入等工艺条件对聚合转化率和聚合物相对分子质量的影响。     

三元共聚物P(IA/MA/AMPS)的合成及阻垢性能评价

以衣康酸(IA)、马来酸(MA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,以过硫酸铵为引发剂,以水为溶剂,通过自由基聚合合成了一种新型的三元共聚物,探讨了单体配比、聚合温度、引发剂用量、聚合时间等合成条件对阻垢性能的影响,确定了最佳的合成条件为:单体配比n(IA)∶n(MA)∶n(AMPS)=1∶1∶1,聚合温度80℃,引发剂占单体质量分数的5%,聚合时间2h;用红外分光光度仪分析证明得到了预期的产物结构,并测定了产物的特性黏度和固含量。通过静态法对三元共聚物的阻垢性能进行评价,在加剂量为50mg/L时阻碳酸钙率最佳可达93.6%,是一种性能优异的阻垢剂。     

碳纤维前驱体聚丙烯腈原丝的亲水改性研究

传统方法中一般采用衣康酸(IA)与丙烯腈(AN)共聚合来制备纺丝原液。笔者用衣康酸铵[(NH4)2IA]取代IA与AN共聚。与P(AN-co-IA)相比,P[AN-co-(NH4)2IA]的亲水性明显提高,相应的,P[AN-co-(NH4)2IA]原丝在蒸汽牵伸过程中能承受更高牵伸比,因而纤度低,强度高。笔者研究了(NH4)2IA取代IA后,聚合反应速率和聚合物分子量的变化。并时反应产物进行了亲水性能测试和DSC分析。亲水改性是提高聚丙烯腈原丝性能的一条有效途径。     

新型无磷反渗透膜用阻垢剂的制备及性能研究

以衣康酸(IA)、甲基丙烯磺酸钠(SMAS)、天冬氨酸(ASP)为单体,过硫酸铵为引发剂,采用水溶液自由基聚合合成三元共聚物阻垢剂.以单体配比、引发剂用量、聚合温度、聚合时间4因素为基础,设计正交实验优化了共聚物的合成条件.利用红外光谱仪对共聚物的结构进行表征,表明其含有羧基、磺酸基、酰胺基等官能团.采用静态阻垢法考察了阻垢剂用量、反应温度及pH对共聚物阻垢性能的影响,并结合动态模拟实验表明其适用于高硬度高碱度的反渗透水质.     

IA/AA/AMPS三元共聚物的合成及阻垢性能研究

以水作溶剂,过硫酸铵为引发剂,衣康酸(IA)、丙烯酸(AA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体,合成了IA/AA /AMPS三元共聚物.探讨了引发剂用量、链转移剂用量、反应温度等对共聚物阻垢性能的影响.结果表明,引发剂用量为单体总质量的4.5%,链转移剂用量为单体总质量的9.5%,反应温度为95℃时,共聚...     

IA/N-MAM/SMAS三元共聚物阻垢剂的合成研究

选用衣康酸(IA)、N-羟甲基丙烯酰胺(N-MAM)、甲基丙烯磺酸钠(SMAS)为原料,在过硫酸铵引发下采用水溶液自由基聚合方法合成了一种三元共聚物阻垢剂。分别考察了单体摩尔配比、反应温度、反应时间、引发剂用量对聚合物阻垢剂阻垢性能的影响。确立了IA/N-MAM/SMAS的最佳合成工艺条件为:单体摩尔配比n(IA)∶n(N-MAM)∶n(SMAS)=2.2∶1.0∶1.0,引发剂用量占单体总质量的10%,反应温度为75℃,反应时间为4 h。利用红外光谱仪对共聚物的结构进行了分析表征,结果表明IA/N-MAM/SMAS中含有羧基、酰胺基和磺酸基。     

Acrylonitrile/ammonium itaconate aqueous deposited copolymerization

Acrylonitrile/ammonium itaconate [AN/(NH₄)₂IA] aqueous deposited polymerizations were studied in this work. It shows that the polymerizations were influenced by various factors, especially the water solubility of AN. In the polymerization process, the system was as separated monomer and water phases, and AN transferred from monomer phase to water phase until the monomer phase disappeared. Because of the solubility of AN in water, the reactivity ratios of monomer calculated by Kelen‐Tudos method were different in various monomer contents. Although (NH₄)₂S₂O₈ was a water‐soluble initiator, there was a short amount of polymer formed in monomer phase. To inhibit the polymerization in monomer phase, two additives were used in the polymerization and experiment data indicated that the two inhibitors exert inhibitory role effectively in monomer phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 904–908, 2006     

水溶性偶氮引发剂AIBA引发AN-MA-IA水相沉淀共聚合的研究

以含有亲水基团的偶氮二异丁脒盐酸盐（AIBA）为引发剂,以丙烯腈（AN）、丙烯酸甲酯（MA）和衣康酸（IA）为单体,β-巯基乙醇（β-ME）为分子量调节剂,采用水相沉淀聚合法制备了不同分子量的AN-MA-IA共聚物,研究了AIBA浓度、单体浓度和β-ME浓度对聚合过程的影响。根据AIBA分解半衰期和单体竞聚规律确定了聚合温度70℃和pH=4.7为较优反应条件。结果表明,AIBA浓度是影响聚合转化率的决定因素,通过调整AIBA浓度可以得到分子量60000~500000的PAN共聚物,较高的AIBA浓度会由于聚合场所的改变而造成分子量分散度小幅上升;浓度在0.2%（质量）以内时,分子量调节剂β-ME可以调控PAN共聚物的分子量,并使其分布变窄。     

Study on monomer reactivity ratios of acrylonitrile/itaconic acid in aqueous deposited copolymerization system initiated by ammonium persulfate

A single water-soluble initiator-ammonium persulfate (APS), not containing alkali metal ions, was first utilized to initiate copolymerization of acrylonitrile (AN)/itaconic acid (IA) in aqueous deposited copolymerization system. Monomer reactivity ratios of this polymerization system were investigated using element analysis method and Q–e schemes. It was found that the monomer reactivity ratios of AN/IA calculated from Q–e schemes are 0.505 (r _AN) and 1.928 (r _IA), while the monomer reactivity ratios of AN/IA in aqueous deposited copolymerization system at 60 °C are 0.64 (r _AN) and 1.37 (r _IA) calculated from Kelen–Tüdõs method, 0.61 (r _AN) and 1.47 (r _IA) from Fineman–Ross method. The three pairs of monomer reactivity ratios are in good agreement. With the increase of the polymerization temperature, the monomer reactivity ratios of AN and IA approach to unity, indicating that the aqueous deposited copolymerization of AN/IA has a tendency to ideal copolymerization. At lower polymerization conversion, the monomer reactivity ratios of AN and IA have hardly any changes. When the polymerization conversion is more than 5%, the monomer reactivity ratio of AN increases, while that of IA decreases.     

Porous acrylonitrile/itaconic acid copolymers prepared by suspended emulsion polymerization

Porous acrylonitrile (AN)/itaconic acid (IA) copolymers were successfully prepared by suspended emulsion polymerization for the first time, with potassium peroxydisulfate (KPS) as an initiator, poly(vinyl alcohol) (PVA) as a dispersant agent, and Span80 as an emulsifier. The effects of the water/monomer mass ratio, agitation conditions, KPS concentration, PVA concentration, Span80 concentration,s and IA concentration on the average particle size and size distribution, particle morphology, and porosity of the AN/IA copolymers were investigated. The results show that the final AN/IA copolymers formed with agglomerates of primary particles had a porous structure, low particle density, and uniform particle size and did not agglomerate easily between the particles. The preparation conditions for the AN/IA copolymers were optimized as follows: (1) the water/monomer mass ratio was 0.3 : 1; (2) the concentrations of KPS, IA, PVA, and Span80 were 0.5, 12.4, 0.1, and 0.5 wt %, respectively, based on the weight of AN separately; (3) the agitation rate was 400 rpm; (4) the polymerization temperature was 70°C; and (5) the reaction time was 3 h. The size of the final AN/IA copolymer particles was in the range 200–400 μm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

丙烯腈水相沉淀聚合生产工艺研究

对丙烯腈/醋酸乙烯酯二元共聚体系进行了研究,分析了影响丙烯腈水相沉淀聚合的工艺因素。结果表明:NaClO3的加入量是单体质量的0.45%~0.65%,m(NaClO3):m(NaHSO3)=(1∶3)~(1∶5),单体浓度为30%~35%,m(AN):m(VAc)控制在7.5~12;聚合停留时间45~50 min;聚合温度55~60℃(偏差在±0.5℃);Cu2+含量30~45 mL/m3;NaNO3加入量为单体质量的0.4%~0.6%;聚合体系pH值是2.1~2.7;巯基乙醇(β-ME)的加入量为单体质量的0.15%~0.55%,搅拌速度为200 r/min左右。在此操作条件下,聚合物平均分子量在48 000~64 000范围内,聚合反应转化率超过81%,不但满足多种性能腈纶纤维的生产要求,而且经济合理。     

正交实验优化低分子质量聚丙烯酸钠合成工艺

采用水溶液聚合法,以丙烯酸为单体,过硫酸铵-亚硫酸氢钠为氧化还原引发体系,亚硫酸氢钠为链转移剂制得分子质量为3000～4000的聚丙烯酸钠。采用粘度法测得产物的黏均分子质量,对丙烯酸单体和聚丙烯酸钠聚合物的FTIR图谱进行了分析,通过正交实验研究了各因素对聚丙烯酸钠分子质量的影响趋势和程度。结果表明:影响最显著的因素为单体浓度,其次为反应温度,再次为引发剂用量,反应时间的影响最小。确定了最佳合成工艺条件:反应温度为45℃,反应时间为4h;丙烯酸单体质量分数为25%,引发剂过硫酸铵用量为单体质量的6%,链转移剂亚硫酸氢钠用量为单体质量的3%。FTIR谱图中不含碳碳双键,且有羧酸盐的特征峰出现,验证了聚合物的合成。该工艺节省能源,且制备方法简单,易于工业化生产。     

Monomer reactivity ratios for acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate

Monomer reactivity ratios of acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate were investigated. Kelen–Tudos method was used to examine the reactivity ratios. It was shown that the reactivity ratios were influenced by the conversions and temperatures of copolymerization. The reactivity ratios in aqueous‐deposited copolymerization system were similar to those in the solution polymerization system at polymerization conversions of less than 5% [reactivity ratio of acrylonitrile (r₁) 0.842 ± 0.02, reactivity ratio of ammonium itaconate (r₂) = 3.624 ± 0.02]. The reactivity ratio of AN rises and that of (NH₄)₂IA decreases, when the polymerization conversion increases till 13%. Aqueous‐deposited copolymerization initiated by AIBN was also studied. It was found that some polymers were formed in water phase and the monomers had different reactivity ratios by comparison with those initiated by ammonium persulfate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4645–4648, 2006     

偏二氯乙烯-丙烯腈悬浮共聚动力学

研究了单体配比、引发剂浓度、聚合温度、转化率等因素对偏二氯乙烯(VDC)-丙烯腈(AN)悬浮共聚树脂的组成、相对分子质量和聚合速率的影响,建立了动力学模型,讨论了AN的水溶性对树脂组成的影响,提出了相对分子质量与聚合温度及引发剂浓度关系的模型。