竹纤维与丙烯酸的共辐照接枝改性

研究了60Co-γ射线辐照对竹纤维和丙烯酸进行接枝共聚反应条件,探讨了单体含量、辐照剂量、pH值等因素对接枝率的影响。研究结果发现,最佳共辐照接枝条件为:单体质量分数40%,辐照剂量5kGy,温度60℃,反应时间6 h,体系pH值为1,此时接枝率可达51.2%。红外光谱和扫描电镜表明丙烯酸与竹纤维发生了化学接枝而非物理吸附。热重分析表明共辐照接枝能改善竹纤维的热稳定性,XRD研究发现共辐照接枝后,竹纤维结晶度降低。     

机械活化玉米淀粉-丙烯酰胺-丙烯酸三元反相乳液接枝共聚反应

以机械活化淀粉为基材,丙烯酰胺(AM)、丙烯酸(AA)为单体,采用反相乳液法合成了接枝共聚物;考察了各因素对接枝共聚反应的影响.实验结果表明,在实验考察范围内的适宜反应条件为引发剂浓度7.30 mmo/L、丙烯酸中和度80%、m(AM):m(从)=0.67、V(油):V(水)=1.2:1、反应温度50℃、m(单体):m...     

甲基丙烯酸丁酯在碳黑上的接枝聚合

研究了甲基丙烯酸丁酯（ＢＭＡ）／碳黑体系中，甲基丙烯酸丁酯在碳黑的接枝聚合及其影响因素，结果表明，反应温度的升高及ＢＰＯ用量的增加，与甲基丙烯酸丁酯在碳黑上的接枝速度几乎无关，仅使甲基丙烯酸丁酯的自聚速度增加。碳黑经接枝处理后，其阻聚性明显下降。     

试验因素对LDPE熔融接枝AA影响的灰色系统分析

研究了丙烯酸作为接支单体,过氧化二异丙苯作为引发剂,与低密度聚乙类混合,在单螺杆挤出机中进行熔融接枝反应,测定了ＬＤＰＥ－ｇ－ＡＡ的熔融旨数和表征接枝率的吸光比。结果表明,各因素对ＭＩ和Ｒ的影响程度是不同的,ＡＡ掺入量与ＭＩ有密切相关,而ＤＣＰ加入量对ＭＩ影响程度较小。     

用于除去浓缩果汁中微量重金属的螯合纤维的研制--(Ⅱ)PP无纺布紫外接枝丙烯酸的结构与性能

研究单体溶液组成对AA无纺布接枝率的影响,以及接枝前后纤维结构和性能的表征及影响因素。结果显示,以丙酮和水为稀释剂,二苯甲酮为光敏剂,AA浓度1mol／L-7mol／L,适量加入辅引发剂AIBN,接枝率和交换量分别达20％～95％和2mmol／g-6mmol／g。扫描电镜、光学显微和数码照片分别显示纤维表面接枝AA支链的长度和分布,以及铜网支架遮光的局部阻聚证据。IR光谱为接枝历程提供了可靠证据。     

氢键作用对制备线性聚丙烯酸纳米粒子的影响

无稳定剂和交联剂的情况下,在乙腈中利用蒸馏沉淀聚合的方法制备无交联的聚丙烯酸（polyAA）纳米粒子.不同的反应条件下,考察引发剂偶氮二异丁腈（AIBN）和单体丙烯酸（AA）浓度的影响.结果表明最佳的聚合反应条件为AIBN相对于单体质量2%,AA相对于反应介质体积2.5%,在这个条件下线性polyAA纳米粒子的粒径约为254 nm.此外,以纯化后的polyAA纳米粒子作为种子,在引发剂和AA单体存在的条件下,通过种子蒸馏沉淀聚合可得到大粒径的纳米粒子.由于AA单体中羧基间的氢键作用,AA单体被认为是自身交联剂,氢键导致了AA双胞体的形成.在聚合体系中加入三乙胺,AA单体间的氢键被破坏.结果表明：几乎没有线性polyAA纳米粒子合成,当三乙胺的量超过AA单体时,只能得到凝胶,而得不到纳米粒子.     

Improvement of thermal stability of UV curable pressure sensitive adhesive by surface modified silica nanoparticles

Pressure sensitive adhesives (PSAs) with higher thermal stability were successfully prepared by forming composite with the silica nanoparticles modified via reaction with 3-methacryloxypropyltrimethoxysilane. The acrylic copolymer was synthesized as a base resin for PSAs by solution polymerization of 2-EHA, EA, and AA with AIBN as an initiator. The acrylic copolymer was further modified with GMA to have the vinyl groups available for UV curing. The peel strength decreased with the increase of gel content which was dependent on both silica content and UV dose. Thermal stability of the composite PSAs was improved noticeably with increasing silica content and UV dose mainly due to the strong and extensive interfacial bonding between the organic polymer matrix and silica.     

电子束引发双功能基阳离子交换膜的制备

利用电子束引发预辐射接枝技术,在高密度聚乙烯(HDPE)上接枝丙烯酸(AA)和对苯乙烯磺酸钠(SSS),制备一种含羧酸基团和磺酸基团的双功能基阳离子交换膜,详细研究了反应温度、单体总浓度、pH值变化及溶剂类型对接枝率的影响规律,明确了实验条件与接枝率的对应关系。接枝膜的吸水性随接枝率的增加而增强。X射线衍射测试表明,接枝膜结晶度随接枝率的升高而降低。     

Synthesis and characterization of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery

In the present work biodegradable pH-sensitive polycaprolactone/acrylic acid (PCL/AA) hydrogels have been developed using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and benzoyl peroxide as initiator. For these prepared hydrogels swelling studies, sol-gel fraction analysis and porosity measurements were performed. Results show that swelling of the hydrogels decreases on increasing the concentration of PCL and EGDMA, however swelling of hydrogels increases on increasing the concentration of AA. Results of sol-gel fraction analysis show that gel fraction increases on increasing concentration of monomer AA, polymer PCL as well as cross-linker EGDMA. As far as porosity is concerned, it increases on increasing the concentration of AA and PCL while porosity decreases on increasing the concentration of EGDMA. Hydrogels were characterized by measuring diffusion coefficient (D) and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were investigated using FTIR, SEM and XRD, respectively. Tramadol hydrochloride was loaded as model drug and its release pattern was analysed using various kinetic models like zero order, first order, Higuchi and Peppas. Results indicated that most of the samples followed non-Fickian release mechanism.     

原位聚合法制备壳聚糖-g-聚丙烯酸/高岭土复合树脂

利用无机粘土矿物与烯类单体的接枝共聚反应制备复合高吸水性树脂,具有改善树脂吸水性能、增强凝胶强度、降低产品成本的优点。以高岭土、壳聚糖和丙烯酸为原料,在水溶液中通过接枝共聚反应合成了壳聚糖接枝共聚丙烯酸/高岭土复合吸水树脂。以丙烯酸量为基准,研究了交联剂、引发剂、壳聚糖、高岭土等与丙烯酸的不同质量比对复合树脂吸水倍率的影响。红外光谱分析结果表明,丙烯酸、壳聚糖和高岭土共同参与了接枝聚合反应。以过硫酸胺为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,丙烯酸中和度为70%,引发剂用量0.3%,交联剂用量为0.05%,壳聚糖与丙烯酸的质量比为0.13,高岭土与丙烯酸质量比为0.13时,高吸水性树脂具有较好的综合吸液性能。     

Ion adsorption studies of micro and nano acrylic fibers modified by ethanolamine

Micro and nano polyacrylonitrile fibers were modified to polyacrylonitrile‐monoethanolamine (PAN‐MEA) through reaction PAN with ethanolamine. The modified PAN fiber was prepared by conversion nitrile groups into hydroxyle groups using ethanolamine solution with different concentration under refluxing at 91°C. Modified raw acrylic fibers (RAF) with submicrometer diameters ranging from 120 to 300 nm were produced using electrospinning in N,N‐dimethyl formamide (DMF). The PAN‐MEA micro and nano fibers were examined as chelating material in a series of batch adsorption experiments for removal of Cu (II), Pb (II) and Ni (II) ions. The fiber structure has been investigated by different experimental techniques of characterization such as Fourier transform infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Also, the physical and mechanical properties has been investigated in this study. Nano fibers show adsorption metal ions more than the usual fiber because of high ratio of surface to mass.     

Effect of acrylic copolymer and terpolymer composition on the properties of in-situ polymer/silica hybrid nanocomposites

Acrylic copolymer- and 5% acrylic acid (AA) modified terpolymer-silica hybrid nanocomposites were synthesized by free radical bulk polymerization of ethyl acrylate (EA), butyl acrylate (BA) and acrylic acid (AA) with simultaneous generation of silica from tetraethoxysilane by sol-gel reaction. The pure polymers were analyzed by using Fourier Transform infrared (FTIR) spectroscopy and solid state nuclear magnetic resonance (NMR) spectroscopy. The hybrid samples were characterized by scanning electron microscopy (SEM), FTIR spectroscopy, NMR spectroscopy, dynamic mechanical, mechanical and thermal properties. SEM images confirmed the presence of nanosilica particles within the polymer matrices, whose dispersion and particle size distribution and visual appearance were dependent on the relative polarity (hydrophilicity) of the polymer matrices and the concentration of the filler. There was no evidence of strong chemical interaction between the polymers and the dispersed silica phase, as confirmed from the FTIR results. Terpolymer-silica hybrids demonstrated superior mechanical properties compared to the copolymer-silica hybrids. They also showed higher dynamic storage modulus and positive shift in the loss tangent peaks. The thermal stability of the nanocomposites was marginally higher which was possibly due to the dipolar interaction at the organic-inorganic interface.     

双重引发POE官能化及其增韧PA66的研究

采用双螺杆加工过程中的机械力引发同时添加引发剂的双重引发方法,研究了引发剂的用量、螺杆转速和接枝反应温度对马来酸酐接枝POE产物的接枝率、熔融指数的影响.对单纯采用引发剂引发方法和引发剂与机械力双重引发方法所得接枝产物增韧PA66的效果也进行了比较.     

淀粉-丙烯酸-丙烯酰胺三元接枝物的制备及性质研究

在60 Co间歇式共辐射条件下探讨了淀粉与丙烯酸和丙烯酰胺流变相态的接枝共聚反应;采用FTIR和SEM对接枝产物共聚物进行了结构表征;考察了丙烯酰胺和丙烯酸盐单体的配比、原料配比、辐射剂量等因素对聚合物吸水率、耐盐性等的影响。结果表明,在没有添加任何化学引发剂的情况下可以得到较高耐盐性和高吸水速率的淀粉-丙烯酸-丙烯酰胺共聚物,克服了传统生产方法中耐盐性低、吸水速度慢、高污染、高耗能等问题。     

熔融挤出制备官能团化FPP的物性及其对PP力学性能的影响

用熔融挤出法制备了不同接枝率的官能团化聚丙烯（FPP），并研究了FPP结晶与熔融行为，热稳定性，结晶形态与晶型及FPP加入对PP力学性能的影响，随着FPP接枝率的提高，其结晶温度，熔融温度，结晶度和热稳定性提高，熔融双峰变成单峰，FPP加入对PP强度优势影响。     

橡胶分子链在玻璃纤维表面的接枝

采用分子结构中含不饱和双键的偶联剂对玻璃纤维进行表面处理,然后在玻璃纤维表面涂覆过氧化物引发剂（ＢＰＯ）及橡胶溶液、使橡胶分子链在引发剂的作用下与玻璃纤维表面的偶联剂进行接枝反应,在玻璃纤维表面接枝了一层橡胶分子链,初步分子橡胶分子链在玻纤表面的反应机遇,对几种橡胶（ＥＰＤＭ、顺丁橡胶、丁苯橡胶、丁腈橡胶、氨丁橡胶）在玻璃纤维表面的接枝能力及反应条件对橡胶分子链在玻璃纤维表面接枝率的影响进行了研究。     

尼龙-6膜与丙烯酸接枝共聚合的研究

通过一系列实验选择以（NH4）2（NO）6／HSO4为引发剂,了尼龙－6膜与丙烯酸的接枝共聚合反应,通过改变单体浓度,反应温度,（NH4）2Ce(NO3)6浓度,H2SO4浓度,尼龙－6膜在甲酸中的溶胀时间等因素发现,接枝膜的接枝率与单体浓度有关,。随单体浓度的改变,接枝率有一个极大值,单体浓度高于或低于此浓度,接枝率都较低,通过改变（NH4）2Ce(NO3)6和H2SO4浓度也得到类似规律,反应温度对接枝膜的接枝率也有影响,温度过高（＞70度）或过低（小于40℃）都得不到较高的接枝率;将尼龙－6膜在20％甲酸中溶胀,有利于提高产物的接枝率。     

耐盐性高吸水树酯的制备及性能

以丙烯酸和2-丙烯酰胺基-2-甲基丙磺(AMPS)为单体,采用溶液聚合法合成了聚(丙烯酸盐-co-2-丙烯酰胺基-2-甲基丙磺酸盐)高吸水性树脂。考察了交联剂、引发剂用量,AMPS与丙烯酸摩尔比,AMPS水溶液浓度,丙烯酸和AMPS中和度,反应温度等因素对吸水树脂吸水性能的影响。制得的吸水性树脂30min吸蒸馏水和0．9％NaCl水溶液分别为1350g／g和150g／g,且凝胶强度较好。     

电子束辐照诱导丙烯酸接枝尼龙66织物的改性研究

利用电子束引发丙烯酸单体接枝尼龙66织物,研究不同接枝条件对接枝反应的影响。利用红外光谱仪(FTIR)、热重分析仪(TGA)、扫描电镜(SEM)以及YG065型织物强力仪研究了接枝前后织物的化学结构、热性能、表面形貌及力学性能变化,并通过垂直燃烧评价接枝织物的抗熔滴性能。结果表明:红外谱图1720.2cm-1等处出现单体中羧基的特征吸收峰,说明丙烯酸成功接枝到尼龙66上。接枝后,尼龙66织物的抗熔滴性得到显著改善,主要因为交联状炭层骨架对纤维熔体的支撑作用,但力学性能有一定程度降低。随着接枝率的增加,尼龙66的初始分解温度逐渐降低,成炭性能明显提升,织物损毁长度变短,熔滴速率更低,而断裂强力有轻微提升。     

聚乙烯表面亲水化改性及其血液相容性改进

以过氧化苯甲酰（BPO）为引发剂,在聚乙烯（PE）膜表面接枝丙烯酸（AA）以改善其亲水性。系统地讨论了引发剂浓度、单体浓度、反应温度以及反应时间等各影响因素对接枝率的影响,并通过傅立叶变换红外（FT-IR）、表面水接触角等物理手段来表征接枝膜的表面结构、亲水性等性能。实验结果表明BPO能成功引发丙烯酸接枝PE膜,接枝改性后PE膜亲水性有了明显的提高。采用了3种比较直观的常规评价方法对PE膜接枝改性前后的血液相容性进行初步的评价。研究结果表明表面接枝AA后的PE膜与血细胞的相互作用较弱,对血细胞的破坏程度明显减小,其抗凝血性比未接枝改性膜有显著提高。