偏氯乙烯／丙烯腈共聚树脂浸渍发泡剂的研究

采用浸渍法在偏氯乙烯／丙烯腈共聚树脂中引入发泡剂，研究了树脂组成和性能、浸渍温度和时间等因素对浸渍量和浸渍速率的影响。     

红外法测定液体橡胶中丙烯腈含量

液体橡胶中丙烯腈含量的测定一般采用经典的凯乐定氮法,此方法不驻费时而且操作繁琐。用红外分光光度法测定胶中丙烯腈含量,所得结果与凯乐定氮法相同,但比凯氏定氮法简便、快速。     

偏氯乙烯-丙烯腈悬浮共聚树脂的颗粒特性

采用悬浮聚合制备偏氯乙烯(VDC)均聚树脂和偏氯乙烯-丙烯腈共聚(VDC-AN)树脂,考察了AN含量对VDC-AN树脂颗粒形态和结晶特性的影响。结果表明,随着AN含量的增加,VDC-AN树脂颗粒形态逐渐由疏松结构向致密结构变化。当AN的质量分数小于或等于8.8%时,共聚树脂具有疏松的颗粒结构,颗粒内部有0.1～2.0 μm的初级粒子间孔隙;当共聚物中AN的质量分数大于或等于12.3%时,颗粒内部初级粒子黏并严重,初级粒子间孔隙基本消失,且共聚树脂基本不结晶。AN单体的引入,使VDC聚合物结晶性下降,单体对聚合物的溶胀性增加,是VDC树脂颗粒由疏松向致密结构转变的主要原因。     

氯乙烯-丙烯腈共聚阻燃纤维的性能研究

采用乳液聚合方法制备氯乙烯-丙烯腈共聚物,得到的共聚物本身具有良好的阻燃性能。将共聚物通过湿法纺丝,得到了阻燃纤维。用热重分析法和电子单纱强力仪对纤维的热稳定性能和机械性能进行了表征,并用扫描电镜对纤维的表面进行观察,同时测定了该纤维的极限氧指数。结果表明:氯乙烯-丙烯腈共聚纤维的极限氧指数可达28.8%～32.5%,燃烧时无滴落现象,且离火即熄;氯乙烯-丙烯腈共聚物阻燃纤维的力学性能较普通腈纶略低。     

燃烧法测定丁腈橡胶中结合丙烯腈含量

采用燃烧法,通过元素分析仪测定了丁腈橡胶( NBR) 中结合丙烯腈含量,考察了试样制备条件及试样质量对测定结果的影响,分析了方法的精密度,并与凯氏定氮法测定结果进行了对比。结果表明,试样制备的适宜抽提时间和干燥时间分别为1. 0,2. 0 h,试样质量宜为2 mg; 该方法的相对标准偏差为 0. 24% ～ 0. 53%,精密度较好; 对于结合丙烯腈质量分数为20% ～ 40%的NBR,燃烧法测定结果与凯氏定氮法无显著性差异,稍高于凯氏定氮法,两者差值为1. 13% ～ 1. 64%,且测定时间缩短至15 min 左右。     

丙烯腈和偏二氯乙烯共聚

以丙烯腈和偏二氯乙烯的共聚机理为基础，分析了共聚反应动力学及共聚物组成，简述了丙烯腈和偏二氯乙烯共聚工艺及杂质对共聚反应的影响。     

梯度淋洗法测定氯乙烯-丙烯腈共聚体的分子量分布

去年曾初步报导了以梯度淋洗法测定氯乙烯-丙烯腈共聚体分子量分布工作的一些结果,并肯定了氯乙烯-丙烯腈共聚体的丙酮-甲醇体系梯度淋洗法按分子量分级的有效性。本文对分级操作的若干细节作了些改进,在基本上消除倒级现象的基础上进行了若干条件试验。分级数据以董履和函数处理,并用加和法验证了实验的分级曲线。最后,我们把淋洗分级的结果同丙酮-甲醇体系在40℃下的柱上溶解分级的结果进行了比较,结果两曲线几乎重合在一起。因此,作为生产部门的常规分析来说,采用柱上溶解分级测定氯乙烯-丙烯腈共聚体的分子量分布,是一种简便迅速的方法。     

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。     

氯乙烯—丙烯腈乳液共聚

本文简述以氯乙烯(VC)——丙烯腈(AN)共聚,通过乳液聚合制取AN含量50％左右,平均分子量为6～8万供纺丝用的共聚体。本文主要讨论以上两种单体的初始投料比,反应过程中AN补加方式和速度对共聚体组成的影响;讨论乳化剂用量、种子含量、反应温度等工艺条件对共聚体平均分子量的影响;以及乳液后处理,即破乳、离心、干燥方法和过程。     

丙烯腈含量对ABS树脂性能的影响

通过乳液接枝聚合法合成丙烯腈-丁二烯-苯乙烯共聚物(ABS)接枝粉料,与苯乙烯-丙烯腈共聚物(SAN)树脂熔融共混得到ABS树脂。探究丙烯腈含量对ABS树脂性能的影响。结果表明：随着丙烯腈含量增加,ABS树脂的拉伸强度、冲击强度、耗散因数、体积电阻率、维卡软化温度以及两相之间相容性上升,但熔体流动速率、表面电阻率、介电常数下降。     

氯乙烯-丙烯腈共聚物/二氧化硅纳米复合材料的制备

将改性后的纳米二氧化硅加入乳化剂溶液.充分乳化后,加入氯乙烯和丙烯腈乳液进行共聚反应,制得氯乙烯-丙烯腈共聚物/二氧化硅纳米复合材料,经过测试,加入纳米二氧化硅的氯乙烯一丙烯腈共聚物的热稳定性能和阻燃性能均有所提高.     

AN-VAc-AMPS三元共聚合研究

介绍了丙烯腈 ( A N) -醋酸乙烯 ( VAc) (或丙烯酸甲酯 ( MA ) -2 -丙烯酰胺基 -2 -甲基丙磺酸 (英文缩写 AMPS)三元共聚合体系各组分竞聚率的测定方法 ,并比较三元共聚体系和二元共聚体系的AN /VAc竞聚率 ,对三元连续共聚进行了试验 ,讨论 A MPS含量与染色性的关系 ,聚合工艺条件与转化率关系。对聚合物溶液的流变性能及纺丝工艺 ,纤维的性能作了简单介绍。聚合及纺丝试验结果证明 ,以 AMPS为第三单体的三元共聚体系可纺性良好 ,所得纤维的物理性能、染色性能、吸水性和抗静电性均优于一般腈纶     

Graft copolymerization of acrylonitrile and methyl methacrylate monomer mixtures on crumb natural rubber

Graft copolymerization of mixtures of acrylonitrile and methyl methacylate on crumb natural rubber was carried out in toluene at 60°C. The nitrogen content of the grafted copolymer was determined by elemental analysis and used to estimate the composition of the copolymer samples. It was found that the amount of acrylonitrile monomeric units incorporated into the polymer was disproportionately lower than the acylonitrile content of the feed and explanations in terms of the e‐value of the monomers and the inherent heterogenous nature of the polymerization mixture were offered. The miscibility of the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) with poly(vinyl chloride) was studied by viscometry, differential scanning calorimetry, and phase contrast microscopy. It was found that the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) formed semimiscible blends with poly(vinyl chloride). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1872–1877, 2002; DOI 10.1002/app.10474     

Thermal behavior of acrylonitrile carboxylic acid copolymers

Polyacrylonitrile (PAN) and copolymer of acrylonitrile–vinyl acids prepared by solution polymerization technique have been characterized by Differential Scanning Calorimetry (DSC) (under dynamic as well as isothermal conditions), themograviemetric analysis (TGA), and on‐line DSC‐FTIR spectroscopy. The DSC of copolymers was carried out at 5°C/min in nitrogen and air. In nitrogen atmosphere the DSC exotherm show a very sharp peak, whereas, in air atmosphere DSC exotherm is broad, and starts at a much lower temperature compared to what is observed in nitrogen atmosphere. The initiation temperature of PAN homopolymer is higher than that for the copolymers. For instance, the initiation temperature of PAN in air is 244°C, whereas, the onset of exothermic reaction is in the range of 172 to 218°C for acrylonitrile–vinyl acid copolymers. As the vinyl acid content increases the ΔH value reduces. The ΔH value of PAN in air was 7025 J/g, whereas, for P(AN‐AA) with 5.51 mol % of acid it was 3798 J/g. As the content of acrylic acid comonomer is increased to 17.51 mol % the value of ΔH decreases further to 1636 J/g. The same trend was observed with MAA and IA as well. DSC‐FTIR studies depict various chemical changes taking place during heat treatment of these copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 685–698, 2003     

Stability of acrylonitrile/methyl vinyl ketone copolymer solutions

Methyl vinyl ketone was successfully copolymerized with acrylonitrile for the first time. This was achieved with azobisisobutyronitrile as the initiator. The viscosity behavior of solutions of the acrylonitrile/methyl vinyl ketone copolymers was determined. The solution agreed with the character of Newtonian flow at the lower shearing rate. The addition of mechanical mixing obviously prevented an increase in the viscosity of the copolymer solutions. When dimethylformamide was used as an additive, the solution viscosity decreased monotonically. When H₂O was used as an additive, the viscosity of the copolymer solutions decreased continuously with concentrations of H₂O up to 4 wt % and then increased. The viscosity of the copolymer solutions decreased continuously with concentrations of KCl and NaCl up to 0.03 mol/L and then increased. Within the first 10 h, there was a great drop in the viscosity of the copolymer solutions containing sodium ethoxide and sodium hydroxide, and then the viscosity appeared to increase. The composition with 12 wt % acetic acid in dimethyl sulfoxide could be considered to be a Θ solvent for the acrylonitrile/methyl vinyl ketone copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3377–3381, 2006     

丙烯腈、醋酸乙烯酯分析新方法的研究

本文研究一种一次性即可快速有效测试釜内和空间丙烯腈、醋酸乙烯酯浓度的新方法。摒弃了先前在测定丙烯腈、醋酸乙烯酯浓度时必须两种物质分别独立操作的方法,既减轻了工人的劳动强度,又为公司节约了资金。本方法适于腈纶生产厂釜内和空间丙烯腈、醋酸乙烯酯浓度的测试。     

丙烯腈含量对AS工程塑料性能的影响

以苯乙烯、丙烯腈为原料,在过氧化苯甲酰引发下本体反应合成AS工程塑料。考察了丙烯腈含量对其共聚物性能的影响。结果表明,随着丙烯腈含量的增加,共聚物的静态力学性能有相应提高;相对丙烯腈含量为15%而言,25%处冲击强度和弯曲强度的提高率分别为232.91%和32.31%。红外谱图表明,苯乙烯与丙烯腈之间发生了共聚反应。     

氯乙烯-丙烯腈共聚物的开发及应用

叙述了氯乙烯-丙烯腈共聚物的难燃性、耐化学药剂性及热成型性等主要性能。指出,该共聚物可制得较优良的阻燃材料,并讨论了该共聚物的聚合方法。     

Polycarbonate blends with styrene/acrylonitrile copolymers

Lap shear adhesion between laminated sheets of polycarbonate and styrene/acrylonitrile copolymers exhibits a sharp maximum when the acrylonitrile content of the copolymers is in the range of 25–27% by weight. Observations of shifts in glass transitions of the two phases in melt-mixed polycarbonate/SAN blends suggest partial miscibility of one polymer in the other, and this solubility is at a maximum when the SAN copolymer has an acrylonitrile content in the same range causing maximum adhesion. Mechanical properties of injection-molded blends of polycarbonate with various SAN copolymers were also best when the acrylonitrile content was the same as that giving maximum adhesion. The partial miscibility behavior in blends as a function of acrylonitrile content of the copolymer is explained qualitatively in terms of a simple binary interaction model.     

结合丙烯腈标准物质不确定度的分析评定

以丁腈橡胶为结合丙烯腈含量标准物质定值样品,对结合丙烯腈含量测量不确定度的来源进行了分析和评定。结果表明,影响丁腈橡胶结合丙烯腈含量标准物质不确定度的因素主要有样品均匀性、样品稳定性和各实验室定值结果的重复性。经过评定,丁腈橡胶结合丙烯腈含量标准物质测定的不确定度为0.26%,标称值为29.1%±0.26%。