聚丙烯纤维与丙烯酸接枝共聚反应的研究

用高锰酸钾 /硫酸作为引发体系 ,聚丙烯纤维与丙烯酸进行接枝共聚反应。研究聚丙烯纤维接枝率与硫酸浓度、丙烯酸浓度、高锰酸钾浓度、高锰酸钾预处理纤维时间、预引发时间、聚合温度和反应时间的关系。结果表明 :硫酸浓度为 0 .2 mol/ L,高锰酸钾浓度为 5× 10 - 3mol/ L,丙烯酸浓度为 0 .8mol/ L,高锰酸钾预处理时间为 30 min,预引发时间为 32 min,反应温度为 80℃ ,反应时间为 3.5h时 ,接枝率较高。     

衣康酸与尼龙66纤维接枝共聚物的合成与表征

以过硫酸钾/硫酸为引发剂,使尼龙66纤维与衣康酸进行接枝共聚反应。研究了尼龙66纤维接枝率与硫酸浓度、过硫酸钾浓度、衣康酸(IA)浓度、反应温度、时间和预处理时间之间的关系。实验结果表明:在硫酸浓度0.5mol/L、反应温度55℃、反应时间40h时,接枝率较高;尼龙66纤维的预处理时间对接枝率也有较大影响。同时,用FTIR、1HNMR、WAXD等手段对接枝共聚物的结构进行了研究。     

光催化抗菌纤维的制备

将制备锐钛矿TiO2纳米无机粒子工艺与纤维化学改性工艺相结合,以钛酸四丁酯为原料,由纳米粒子表面的羟基与纤维的活性羧基发生酯化反应而接枝在纤维表面,制备出光催化抗菌纤维。本文研究了钛酸四丁酯酯溶液浓度、pH值、温度和时间对接枝率的影响,结果表明,接枝率越高,抗菌性越强,反应物浓度为0.1 mol/L、pH值为4、温度为75℃、时间为2 h时,接枝率达到16.40%。     

高锰酸钾引发聚酯纤维接枝共聚改性研究

研究了用KMnO_4/H_2SO_4作为引发剂,聚酯(PET)纤维与丙烯酸接枝共聚的改性方法,探讨了间甲酚浸泡时间和温度、KMnO_4浓度、H_2SO_4浓度、丙烯酸(AA)浓度等对接枝率的影响。结果表明:间甲酚浸泡时间2h、浸泡温度60℃、KMnO_4浓度3.0×10~(-3)mol/L、H_2SO_4浓度0.02mol/L、AA浓度2.66mol/L、反应时间2h时,PET纤维的接枝率较高;同时,用红外光谱证明了聚丙烯酸接枝支链的存在。     

木薯淀粉与醋酸乙烯酯的接枝共聚研究

以木薯淀粉为接枝骨架,过硫酸铵为引发剂,醋酸乙烯酯(VAC)为接枝单体,进行接枝共聚。研究了单体浓度、引发剂浓度、反应时间、反应温度对淀粉醋酸乙烯酯接枝共聚反应的影响,并通过正交试验,确定了最佳反应条件。结果表明:当单体浓度为1.1mol/L、引发剂浓度为18.3×10-3mol/L,反应温度60℃、反应时间3~3.5h时,可得到高的单体转化率、接枝效率和接枝率,并用SrectrumOne红外光谱对接枝物的化学结构进行了分析。     

粘胶纤维接枝共聚研究

用高锰酸钾为引发剂 ,将粘胶纤维与丙烯酸接枝共聚 ,研究了接枝共聚反应工艺条件对接枝率的影响。结果表明 :高锰酸钾浓度 ,预处理温度、时间 ,硫酸浓度 ,丙烯酸浓度 ,反应温度、时间均与接枝率有关 ,反应中选择高锰酸钾浓度 0 .0 7mol/ L ,预处理温度 5 0℃、时间 2 0 min,硫酸浓度 0 .0 8mol/ L ,丙烯酸浓度 1.2 m ol/ L ,反应温度 90℃ ,粘胶纤维接枝率可高达 72 %。     

Ce~(4+)引发聚乙烯醇接枝甲基丙烯酸甲酯

以硝酸铈铵 (CAN)作引发剂 ,在水介质中聚乙烯醇 (PVA)接枝聚合甲基丙烯酸甲酯 (MMA) ,用红外光谱证实接枝物的结构 ,讨论了单体浓度、引发剂浓度、p H值、反应时间及温度对接枝率的影响 ,最佳反应条件为 PVA1 .0 g/l,CAN3 .1 6× 1 0 - 3mol/l,HNO30 .1 88mol/l,MMA0 .469mol/l,45℃ ,4h。     

铈盐引发MMA/氨基树脂磷酸酯共聚物的合成

酸性条件下,以硫酸铈(Ⅳ)为引发剂,合成了MMA/氨基树脂磷酸酯(ARP)接枝共聚物。研究了单体与ARP体积比、引发剂浓度、反应温度和反应时间对接枝参数的影响,其最佳合成工艺为:V[MMA]︰V[ARP]=4︰8;C[Ce(Ⅳ)]=3.95×10-3 mol/L;反应温度为35℃;反应时间为3 h。经红外光谱、磷含量测定证明了接枝反应的可行性,热分析结果表明接枝产物比PMMA有更高的热稳定性。     

CAN-KPS引发大豆分离蛋白与醋酸乙烯酯接枝共聚的研究

以大豆分离蛋白（SPI）为原料，硝酸铈铵一过硫酸钾（CAN—KPS）为复合引发体系，尿素溶液为助剂，接枝共聚醋酸乙烯酯（VAc）。研究了不同条件对SPI接枝VAc反应的影响，确定该反应体系的最佳反应条件：CAN—KPS浓度为15mmol/L，VAc浓度为0．35mol／L，反应时间为24h，反应温度为50℃，SPI糊化时间为40min。     

吸水膨胀弹性体PVA-g-PBA的研究

在水介质中.在氮气保护下以硝酸铈铵(CAN)为引发剂,将丙烯酸丁酯(BA)接枝到聚乙烯醇(PVA)上,制得水膨胀弹性体PVA—g—PBA。通过红外光谱证实了接枝物的形成。讨论了PVA浓度、单体浓度、引发剂浓度和反应温度对接枝物接枝率(G％)的影响。结果表明随PVC浓度增大,接技率降低.[PVA2.5×10-4mol/L.[BA]0.702mol/l、[CAN]0.01mol/L45℃接枝率较高.接枝率越高其吸水膨胀率越低,8h达吸水平衡,最大吸水率为165.1％。     

引发剂对纤维素接枝丙烯酰胺反应的影响

分别以硝酸铈铵、过硫酸钾和过硫酸钾/亚硫酸钠为引发剂,以马尾松漂白硫酸盐浆纸浆纤维素为骨架接枝丙烯酰胺,在单体浓度为0.75 mol/L、温度为45℃、反应时间为3 h时,得到硝酸铈铵和过硫酸钾的最佳浓度为3.0 mmol/L和5.0 mmol/L,过硫酸钾/亚硫酸钠在用量为6%时的最佳质量比为1.5,三者相应的接枝率分别为40%、48%和60%。同时比较了不同条件下三种引发剂的接枝效果,结果表明,过硫酸钾/亚硫酸钠的接枝效果最好,但均聚物含量高;硝酸铈铵作为引发剂虽然接枝效果不及前两者,但均聚物含量很低。     

淀粉接枝型高分子絮凝剂的合成

用硝酸铵作引发剂,研究了淀粉－丙烯酰胺接枝共聚物高分子絮凝剂制备的工艺条件。实验结果表明,影响接枝聚合后反应的最佳工艺条件为：硝酸胺浓度１．０＊１０＾－３ｍｏｌ／Ｌ,单体丙烯酰胺浓度１．４ｍｏｌ／Ｌ,聚合反应温度５０℃,聚合反应时间３ｈ。同时,还探讨了淀粉接枝聚合反应的机理。     

球形纤维素珠体-AN-AM接枝共聚物的制备

以球形纤维素珠体为原料,丙烯腈(AN)和丙烯酰胺(AM)为单体,硝酸铈铵和过硫酸钾(KPS)为引发剂,制备纤维素珠体-AN-AM接枝共聚物,并通过正交单因素实验,研究了反应温度、引发剂用量、单体用量、反应时间等因素对接枝效果的影响。实验结果表明:当反应温度为60℃,引发剂硝酸铈铵用量为20%,KPS用量为15%(引发剂与单体AN的质量百分比),单体AN浓度为0.75 mol/L,AM浓度为0.28 mol/L,硝酸浓度为0.14 mol/L,反应时间为3 h时,接枝效果最好。此条件下,AN、AM与纤维素的接枝率可达259.4%,接枝效率可达49.40%。     

淀粉接枝丙烯酰氧乙基三甲基氯化铵共聚物的合成

以玉米淀粉为原料,在水介质中通过硝酸铈铵引发淀粉与丙烯酰氧乙基三甲基氯化铵(DAC)接枝共聚,制备系列含阳离子季铵基团的淀粉-DAC接枝共聚物,系统考察了反应条件对接枝共聚物接枝率(PG)的影响。结果表明:在本实验体系内可制备较高接枝率的阳离子接枝共聚物。当硝酸铈铵的浓度为1.5×10-2mol/L,m(DAC)∶m(淀粉)=3,反应温度40℃,反应时间4 h时,接枝共聚物的接枝率最高可达118.67%。用FTIR、1HNMR、XRD对接枝共聚物结构进行了表征。     

Graft copolymerization of methyl methacrylate and other vinyl monomers onto cotton fabric using ferrous cellulose thiocarbonate–N-bromosuccinimide redox initiation system

The cellulose thiocarbonate, in the fabric from, was treated first with a freshly prepared ferrous ammonium sulphate (FAS) solution. The sotreated fabric formed, with N-bromosuccinimide (NBS), an effective redox system capable of initiating grafting of methyl methacrylate (MMA) and other vinyl monomers onto the cotton fabric. The effect of the polymerization conditions the polymer criteria, namely, graft yeild, homopolymer, total conversion, and grafting efficiency, was studied. These polymer criteria were found to depend extensively upon concentrations of the Fe²⁺ ion (activator), NBS (initiator), and MMA; pH of the polymerization medium, and duration and temperature of polymerization. Based on detailed investigation of these factors, the optimal conditions for grafting were as follows: Fe²⁺, 1 × 10⁻³ mol/L; NBS, 1 × 10⁻² mol/L; MMA, 4%; pH, 2: polymerization time, 150 min; polymerization temperature, 60°C; material/liquor ratio, 1: 100. Under these optimal conditions, the rates of grafting of different vinyl monomers were in the following sequence: methyl methacrylate ≫ methyl acrylate > acrylonitrile. Other vinyl monomers namely, acrylic acid, and methacrylic acid have no ability to be grafted to the cellulosic fabric using the said redox system. A tentative mechanism for the polymerization reaction is suggested. © 1996 John Wiley & Sons, Inc.     

Graft polymerization of methyl methacrylate onto guar gum with ceric ammonium sulfate/dextrose redox pair

The effect of different reaction conditions on the grafting of methyl methacrylate (MMA) onto guar gum (GG) has been studied in detail. The grafting efficiency was optimal under the following conditions: MMA at 1.13 mol/L; ceric ammonium sulfate at 6.32 × 10^?3 mol/L; dextrose monohydrate at 2.428 × 10^?3 mol/L; GG at 4 g/L; temperature at 50°C; and time at 210 min. Fourier transform infrared spectroscopy was used for the confirmation of copolymer formation. Thermogravimetric analysis of GG and a representative graft copolymer were studied. A probable mechanism of grafting has been suggested. The biodegradability of the resulted copolymer was evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3520–3525, 2001     

壳聚糖-甲基丙烯酰氧乙基三甲基氯化铵接枝共聚物的制备与絮凝性能研究

以壳聚糖和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,硝酸铈铵为引发剂,Span-20为乳化剂,通过反相乳液聚合技术,合成了壳聚糖-DMC接枝共聚物。通过正交试验考察了反应条件对接枝度的影响,得出的最佳工艺条件为:反应时间5 h、引发剂浓度16 mmol/L、壳聚糖与DMC质量比1:6、油水体积比1:1。最佳条件下平均接枝度达到110 %。将得到的壳聚糖接枝共聚物用作絮凝剂处理高岭土悬浮液,结果表明其絮凝性能优于壳聚糖和聚丙烯酰胺(PAM),且在pH值6.0、投加量为2.0 mg/L时絮凝效果最佳。     

Graft polymerization of methyl methacrylate onto wool using dimethylaniline/copper(II) system

Dimethylaniline (DMA)/Cu^II-induced grafting of methyl methacrylate (MMA) onto wool fibres was studied under different conditions. The grafting reaction was found to be influenced by Cu^II, DMA, and MMA concentrations as well as polymerization temperature, reaction time, and polymerization medium. While the graft yield increased by increasing the amount of MMA from 100 to 500 mmol/L, maximum grafting occurred at 0.5 mmol/L CuSO₄, 10 mmol/L DMA. The graft yield increased by increasing the reaction time from 15 to 150 min and by raising the polymerization temperature from 60 to 80°C. Using dimethylformamide/water and ethyl alcohol/water mixture as a medium for grafting decreased the graft yield, while using isopropyl alcohol/water mixtures increased the graft yield as compared to pure aqueous medium.     

Preparation of microwave radiation induced graft copolymers and their applications as reinforcing material in phenolic composites

Flax fiber was modified through grafting of binary vinyl monomers mixtures such as methyl methacrylate (MMA)/vinyl acetate (VA), MMA/acrylamide (AAm), and MMA/styrene (Sty) under the influence of microwave radiations. 24.64% grafting was found at 210 W microwave power under optimum reaction conditions. Graft copolymers obtained were characterized with FTIR spectroscopy, scanning electron microscopy, and TGA/DTA techniques. Graft copolymers were found to be moisture retardant with better tensile strength. Phenolic composites using graft copolymers vis‐à‐vis flax as reinforcing material were subjected for the evaluation of different mechanical properties such as wear resistance, tensile strength, compressive strength, modulus of rupture (MOR), modulus of elasticity (MOE), and stress at the limit of proportionality (SP). Composites reinforced with graft copolymers showed better mechanical properties in comparison to composites reinforced with flax. Phenolic composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum wear resistance followed by reinforcement with flax, Flax‐g‐poly (MMA/AAm), and Flax‐g‐poly(MMA/VA). Composites reinforced with Flax‐g‐poly(MMA/Sty) and flax fibers have been found to show 150 N tensile strength with extension of 3.94 and 2.17 mm, respectively. It has also been found that composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum compressive strength (1,000 N) with compression of 3.71 mm in comparison to other graft copolymers and flax fibers reinforcement. Reinforcement of phenolic resin with Flax‐g‐poly(MMA/Sty) and flax fibers could improve the MOR and MOE. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

表面接枝高密度磺酸基聚苯乙烯的制备及表征

以无水溴化铝为催化剂,对氯苯甲醛为醛基化试剂,通过傅克反应在聚苯乙烯微球表面接枝醛基;基于醛基的可氧化性,利用还原剂硝酸铵铈将树脂微球表面的醛基自由基化,引发对苯乙烯磺酸钠在树脂微球表面聚合,并对其进行表征。结果表明,聚苯乙烯微球磺酸化改性成功,优化的磺化工艺条件为:醛基含量1.5 mmol/g的聚苯乙烯微球用量0.3 g,对苯乙烯磺酸钠质量浓度40 g/L,硝酸铵铈质量浓度40 g/L,反应温度70℃,在此条件下制备的树脂表面磺酸基含量为58 mmol/g。