甲基丙烯酸羟乙酯接枝天然橡胶对白炭黑/天然橡胶复合材料性能的影响

研究甲基丙烯酸羟乙酯（HEMA）接枝天然橡胶（NR）（NR-g-HEMA）接枝率和用量对白炭黑/NR复合材料性能的影响。结果表明：与未加入NR-g-HEMA的白炭黑/NR复合材料相比,加入NR-g-HEMA的白炭黑/NR复合材料的硫化速度、交联程度、邵尔A型硬度、定伸应力和撕裂强度增大,压缩疲劳生热明显降低;当NR-g-HEMA接枝率为10%和用量为10份时,白炭黑/NR复合材料的拉伸强度最大,压缩疲劳生热最低;NR-g-HEMA与NR相容性较好,加入NR-gHEMA的白炭黑/NR复合材料中白炭黑在橡胶相中分散更均匀,两者具有更强的界面结合效果。     

一种利用甲基丙烯酸羟乙酯橡胶接枝改性陶土补强天然橡胶复合材料的制备方法

一种利用甲基丙烯酸羟乙酯橡胶接枝改性陶土补强天然橡胶复合材料的制备方法     

甲基丙烯酸羟乙酯接枝改性淀粉的制备及性能

甲基丙烯酸羟乙酯(HEMA)与降解淀粉(ST)在过硫酸铵(APS)引发下,通过接枝共聚反应,制备了接枝改性淀粉,讨论了APS、HEMA、反应温度和反应时间对接枝效率(GE)和接枝率(GP)的影响。结果表明,在w(ST)=16.4%的水溶液中,当w(HEMA)=5.08%,w(APS)=0.84%时,于50℃反应280 min后,所得接枝改性淀粉的GE和GP分别为40%和27.5%。红外光谱(FTIR)和凝胶渗透色谱(GPC)确证了产物结构。复鞣革应用结果表明,接枝改性淀粉复鞣革的增厚率、丰满度、柔软性、弹性、发泡感等有所提升。接枝改性淀粉复鞣革的力学性能与参考样相当,产物具有复鞣性能。     

甲基丙烯酸β—羟乙酯的合成研究

以十六烷基三甲氢氧化铵为催化剂和苯二酚为阻聚剂,由甲基丙烯酸甲酯和乙二醇合成了甲基丙烯酸β－羟乙酯,通过正交试验获得了最佳反应条件,反应温度１００℃～１１０℃,反应时间２．５ｈ,酯醇摩尔比１：１．５,催化剂用量为９．０ｍｌ,ＨＥＭＡ的产率为９２．３％。     

甲基丙烯酸2-羟乙酯的合成研究

以四甲基氢氧化铵为催化剂 ,由甲基丙烯酸甲酯和乙二醇合成了甲基丙烯酸 2 -羟乙酯。通过正交实验获得了最佳反应条件为 :反应温度 75℃ ,反应时间 4h,酯醇摩尔比 1∶ 2 .0 ,催化剂的用量为 2 .0 ml,产品收率为 91.4%。     

甲基丙烯酸β-羟乙酯的合成研究

以十六烷基三甲基氢氧化铵为催化剂和对苯二酚为阻聚剂,由甲基丙烯酸甲酯和乙二醇合成了甲基丙烯酸β－羟乙酯。通过正交实验获得了最佳反应条件：反应温度１００℃～１１０℃,反应时间２．５ｈ,酯醇摩尔比１∶１．５,催化剂用量为９．０ｍｌ。ＨＥＭＡ的产率为９２．３％。     

甲基丙烯酸羟乙酯合成催化剂的研究

在催化剂和对苯二酚(HQ)-对羟基苯甲醚(MQ)复合阻聚剂存在下,由甲基丙烯酸和环氧乙烷合成甲基丙烯酸羟乙酯(HEMA)。分别对铁系和胺类催化剂进行了筛选研究,得出各自的优缺点。研究发现六次甲基四胺催化反应性能好,反应产物中甲基丙烯酸羟乙酯质量分数达90.0%以上,这为高效催化剂的开发提供了参考依据。     

松香季戊四醇酯与甲基丙烯酸-2-羟乙酯反应研究

松香季戊四醇酯（RPE）环上的共轭双键可以与甲基丙烯酸-2-羟乙酯（HEMA）发生Diels-Alder加成发应,同时松香季戊四醇酯仍有一定酸值,其中未反应的羧基可与HEMA进行酯化反应。研究了反应温度和物料配比对RPE与HEMA反应的影响,对产物进行了红外和热重分析。结果表明：在一定的物料比下,反应温度升高,加成反应和酯化反应速度加快,反应温度提高更有利于酯化反应的进行;在一定的反应温度下,HEMA的物质的量增加,产物的酸值到一定程度不再下降,而溴值持续下降,表明有利于HEMA与RPE的加成反应。红外光谱表明将HEMA接到了RPE的分子结构上,热重分析表明产物的初始分解温度和最终分解温度有所下降。     

纤维素接枝甲基丙烯酸乙酯的合成及表征

在过氧化氢和亚铁离子组成的氧化还原体系中加入第三组分二氧化硫脲(TD),将单体甲基丙烯酸乙酯(EMA)接枝于纤维素纤维上。探讨了单体EMA用量、过氧化氢用量、TD用量、反应温度、反应时间、去离子水用量等因素对接枝率、接枝效率的影响。结果显示纤维素接枝EMA的最佳工艺条件为:纤维8 g,EMA 6 g,过氧化氢0.02 g,TD 0.5 g,去离子水150 mL,反应温度50℃,反应时间1 h。红外光谱、扫描电镜分析均表明EMA接枝到了纤维素结构上。     

Synthesis and Evaluation of β-Cyclodextrin–2-Hydroxyethyl Methacrylate Copolymer as a Novel Adsorbent

2-Hydroxyethyl methacrylate (0·01mol) was allowed to react with 0·01mol of hexamethylene di-isocyanate and the product was coupled to 0·01mol of β-cyclodextrin to form a new cyclodextrin-based copolymer. The interaction of the polymer with different steroids was investigated and the extent of adsorption was in the order cholesterol>progesterone>testosterone. The results indicate that the new polymer matrix could be used for the removal of steroids, particularly cholesterol, from a given medium. The polymer could also be used for sample purification, such as the removal of progesterone from a mixture prior to its analysis by other analytical techniques. The preliminary results show that the polymer may have interesting clinical and analytical applications. © of SCI.     

增容剂甲基丙烯酸丁酯接枝聚丙烯的研究*

以甲基丙烯酸丁酯(BMA)为接枝单体,过氧化苯甲酰(BPO)为引发剂,采用固相接枝技术对聚丙烯(PP)进行改性,制备了BMA接枝PP (PP-g-BMA)。研究了接枝反应工艺条件对接枝率的影响,采用傅立叶变换红外光谱表征与分析了PP-g-BMA,并对PP-g-BMA在PP/聚对苯二甲酸乙二酯(PET)共混物中的增容作用进行了验证。结果表明,当反应温度为130℃、引发剂的质量分数为6%、单体BMA质量分数为10%,接枝反应3 h,成功制得了接枝率为3.75%的PP-g-BMA;PP-g-BMA可明显改善PP/PET共混物的界面相容性,相对于PP-g-MAH,其增容的PP/PET共混物的力学性能和加工流变性能更好。     

Preparation and Mechanical Characterization of Gelatin-Based Films Using 2-Hydroxyethyl Methacrylate Cured by UV Radiation

Gelatin films were prepared from gelatin granules in aqueous medium by casting. Tensile strength, tensile modulus and elongation at break of the gelatin films were found to be 27 MPa, 100 MPa and 4%, respectively. Gelatin films were soaked in five different formulations containing 2-hydroxyethyl methacrylate (HEMA) (10–50%, by wt), methanol and photoinitiator and then cured under UV radiation. Again, a series of gelatin solutions was prepared by blending varying percentages (10–50% by wt) of HEMA and then films were prepared and UV cured. It was found that tensile properties of gelatin films improved significantly.     

硅烷接枝温水交联天然橡胶的研究

以多功能乙烯基硅烷为接枝单体,过氧化苯甲酰为引发剂,通过熔融混炼接枝和温水交联分别制备了硅烷接枝天然橡胶和交联硅烷接枝天然橡胶。采用傅里叶红外光谱仪和扫描电子显微镜分别对硅烷接枝天然橡胶和交联硅烷接枝天然橡胶进行了表征,并研究了接枝单体及引发剂的用量、接枝和交联工艺（温度和时间）等对交联硅烷接枝天然橡胶凝胶含量的影响,同时研究了不同凝胶含量对交联硅烷接枝天然橡胶力学性能的影响。结果表明,天然橡胶发生了硅烷接枝和交联反应;随着接枝单体及引发剂用量、混炼时间和温度以及交联温度和时间的增加,交联硅烷接枝天然橡胶的凝胶含量单调增加;交联硅烷接枝天然橡胶的力学性能随着凝胶含量的增加而明显得到改善,凝胶含量为80%的交联硅烷接枝天然橡胶的拉伸强度比纯天然橡胶提高了30%,断裂伸长率提高了8.5倍。     

RGDS-Modified Superporous Poly(2-Hydroxyethyl Methacrylate)-Based Scaffolds as 3D In Vitro Leukemia Model

Superporous poly(2-hydroxyethyl methacrylate-co-2-aminoethyl methacrylate) (P(HEMA-AEMA)) hydrogel scaffolds are designed for in vitro 3D culturing of leukemic B cells. Hydrogel porosity, which influences cell functions and growth, is introduced by adding ammonium oxalate needle-like crystals in the polymerization mixture. To improve cell vitality, cell-adhesive Arg-Gly-Asp-Ser (RGDS) peptide is immobilized on the N-(γ-maleimidobutyryloxy)succinimide-activated P(HEMA-AEMA) hydrogels via reaction of SH with maleimide groups. This modification is especially suitable for the survival of primary chronic lymphocytic leukemia cells (B-CLLs) in 3D cell culture. No other tested stimuli (interleukin-4, CD40 ligand, or shaking) can further improve B-CLL survival or metabolic activity. Both unmodified and RGDS-modified P(HEMA-AEMA) scaffolds serve as a long-term (70 days) 3D culture platforms for HS-5 and M2-10B4 bone marrow stromal cell lines and MEC-1 and HG-3 B-CLL cell lines, although the adherent cells retain their physiological morphologies, preferably on RGDS-modified hydrogels. Moreover, the porosity of hydrogels allows direct cell lysis, followed by efficient DNA isolation from the 3D-cultured cells. P(HEMA-AEMA)-RGDS thus serves as a suitable 3D in vitro leukemia model that enables molecular and metabolic assays and allows imaging of cell morphology, interactions, and migration by confocal microscopy. Such applications can prospectively assist in testing of drugs to treat this frequently recurring or refractory cancer.     

Synthesis and Characterization of Conducting Composites of Polypyrrole/Polypyrrole-Coated Short Nylon Fiber and Natural Rubber

Pyrrole was polymerized in the presence of anhydrous ferric chloride as oxidant and p-toluene sulphonic acid as dopant. Polypyrrole-coated short Nylon fibers were prepared by polymerizing pyrrole in the presence of short Nylon fibers. The resultant polypyrrole (PPy) and polypyrrole-coated Nylon fiber (F-PPy) were characterized using SEM and then used to prepare rubber composites based on natural rubber. The cure pattern, cure kinetics, filler dispersion, DC conductivity, mechanical properties and morphology of the resulting composites were studied. The presence of PPy-coated fibers in the natural rubber/PPy system reduced the cure time significantly. The DC conductivity of the composites was found to be better for the F-PPy system compared to PPy-filled NR composite. The F-PPy system also showed better tensile strength, modulus and tear resistance.     

Hydrophilic Sponges Based on 2-Hydroxyethyl Methacrylate. III. Effect of Incorporating a Hydrophilic Crosslinking Agent on the Equilibrium Water Content and Pore Structure

The effect of using a hydrophilic crosslinking agent (divinyl glycol, DVG) on 2-hydroxyethyl methacrylate (HEMA) sponge swelling and pore morphology was evaluated. Concentrations of crosslinking agent, redox initiators and HEMA (75–90wt%) in the initial aqueous monomer mixture were varied. Anomalous sponge swelling behaviour, together with the formation of non-uniform stratified sponges was rationalised in terms of the assumed disparate free radical reactivities of DVG and HEMA. Environmental scanning electron microscopy indicated that the stratified sponges did not exhibit suitable porosity for biomedical use. © of SCI.     

氯丁接枝胶粘剂的研制

本文研究了接枝氯丁胶粘剂的制备工艺，反应温度，反应时间，引发剂用量，接枝效率对胶粘剂粘接力的影响．