高密度聚乙烯表面光接枝丙烯酸行为研究

研究了以二苯甲酮为光敏剂时,紫外光辐照时间、温度、丙烯酸(AA)单体浓度、预覆液中光敏剂浓度等因素对高密度聚乙烯(HDPE)接枝率和接枝效率的影响,以及接枝HDPE膜的接触角与接枝率的关系。随辐照时间延长,HDPE的接枝率增加,4min时的接枝率为15％,膜表面对水的接触角由来接枝时的83°降到36°;随接枝时间的进一步延长,接枝率不断增加,但接触角变化不大。升高温度、增加单体浓度,可以促进接枝反应的进行,使接枝率增加。预覆液中光敏剂浓度也影响HDPE的接枝率和接枝效率。红外光谱(IR)结果表明,HDPE膜表面已接枝了PAA。差热分析(DSC)结果表明,接枝破坏了HDPE的结构规整性,影响其结晶度。     

聚合物表面光接枝改性研究进展

表面光接枝主要是用芳酮引发有机材料产生自由基，从而引发单体聚合产生表面接枝链。表面光接枝应用领域广泛．可用于聚合材料的表面改性以及表面功能化。综述了紫外光引发接枝改性聚合物表面的研究进展，包括光接枝聚合机理、改性方法、影响因素等，并对其应用前景及研究方向进行了介绍。     

甲基丙烯酸缩水甘油酯接枝聚烯烃的新进展

本文综述了甲基丙烯酸缩水甘油酯接枝聚烯烃的研究进展。包括常用的接枝方法,可能的接枝机理,接枝率的测定方法及接枝聚烯烃的应用等。     

接枝功能化聚烯烃

聚烯烃功能化是目前人们普遍关注的热点.综述了国内外对聚烯烃进行功能化的各种方法,其中重点讨论了聚烯烃的接枝功能化,并对接枝物的结构性能与应用作了简要介绍.     

聚烯烃接枝的研究进展

介绍了以过氧化物为中间产物的聚烯烃本体接枝、链转移反应、多单体熔融接枝的进展情况,重点阐述了表面接枝中的化学方法、利用辐照和光照技术对聚烯烃的表面改性、等离子体工艺及相关的聚丙烯表面改性剂。聚烯烃接枝是制备功能性聚烯烃的主要方法,也是高分子与工程材料领域最活跃的研究热点之一。     

聚烯烃辐射接枝新进展

本文综述了80年代以来聚烯烃辐射接枝研究的新进展,着重介绍了各种辐射接枝方法的机理和特征,讨论了减少均聚物、促进接枝的有效途径,并对接枝物分布、结构、形态和表征等进行了评述。     

聚烯烃熔融接枝改性

熔融接枝技术是聚烯烃改性的一个重要手段,尤其是聚烯烃的挤出熔融接枝技术。本文介绍了聚烯烃熔融接枝的反应机理和动力学模型,以及接枝聚烯烃的定性定量分析测试方法,并探讨了工艺条件、引发剂与接枝单体用量等对聚烯烃接枝率的影响及接枝对聚烯烃结构与性能的影响。     

分离膜表面光接枝技术研究进展

文章介绍了表面光接枝聚合技术的原理、接枝方法及影响分离膜表面光接枝聚合的因素，如溶剂类型，光敏剂种类及浓度，基膜与单体等。简要阐述了表面光接枝在分离膜上的应用进展，包括合成耐生物污染膜、具有分子识别功能的膜、环境敏感性膜及表面固定化的膜，固定化试剂包括生物试剂、吸附试剂、催化试剂等。     

聚丙烯膜表面光接枝聚合

对聚合物表面进行接枝聚合是一种有效的材料改性方法。近年来,S.Tazuke,Y.Ogiwara,高志民等人做了一些用紫外光引发接枝方面的工作,获得了较满意的结果。为提高聚丙烯(简称为PP)膜的光稳定性,我们研究了将一种受阻胺类光稳定剂,甲基丙烯酸2,2,6,6-四甲基哌啶醇酯(简称为MTMP)光接枝到PP膜表面的聚合过程。MTMP的结构式为:     

高密度聚乙烯(HDPE)薄膜的光接枝改性

在氮气保护、紫外光照射下,以二苯甲酮为光引发剂,丙烯酸在ＨＤＰＥ薄膜表面的光接枝聚合改性。探讨了光照时间、单体浓度、单体种类、溶剂种类等反应条件对接枝效果的影响。用红外光谱、水接触角和染色程度表征接枝效果,水接触角由８０°降至３４．４°,染色程度增加约９９倍。结果表明,表面光接枝改性对薄膜本体的力学性能没有影响。     

聚烯烃薄膜表面气固相光接枝改性

以UV(λ≥320nm)为光源,二苯甲酮为光引发剂,分别以丙烯酸(AA)和α-甲基丙烯酸(MAA)为单体,在LDPE和PP薄膜上成功地进行了表面光接枝改性。接枝薄膜用ATR-IR光谱方法进行测定和表征。辐照时间增加,接枝程度提高。经300秒反应,接枝LDPE薄膜表而水接触们从103°下降至57°。分别测试了接枝薄膜的表面湿张力及染色性,结果表明:一般接枝程度越高,湿张力越大,表而染色越深且均匀。以MAA为单体,在PE上接枝比在PP上容易进行。经PE为基材,用MAA接枝改性效果比用AA的要好。     

粘胶基碳纤维连续式电化学氧化表面处理（1）：碳纤维表面的物理 …

本文报道了用连续式电化学氧化表面处理粘胶基碳纤维表面,并测定了处理后碳纤维的单丝强度,表面浸润性,表面活性官能团含量及表面形貌等表面物理化学性能。结果表明：粘胶基碳纤维经电化学氧化表面处理可以有效地在表面主生活性官能团和提高表面粗糙度,从而有效地提高表面润湿性,但经处理后单丝强度较易下降,因此需精确控制处理的条件。     

PBO纤维表面改性方法的研究

对PBO纤维表面性能的改善进行了研究,考察了混杂芳纶纤维、电晕处理、偶联剂处理及强酸处理等多种方法对PBO纤维与环氧树脂表面粘接强度及其复合材料层间剪切性能的影响程度,比较了各种方法的改性效果及各自优缺点。     

Photografting of acrylic acid on high density polyethylene powder in vapour phase

A photografting technique was explored as a means of functionalizing high density polyethylene (HDPE) powder. The graft copolymerization reaction of acrylic acid on HDPE powder and the surface structure of grafted HDPE powder were studied in terms of grafting degree and grafting efficiency, and by FTIR and ESCA. The results show that the surface of chemically inert HDPE powder pretreated by an acetone solution of benzophenone (BP) can be graft‐copolymerized with acrylic acid by photografting in the vapour phase. Thereby, the grafting degree is increased but the grafting efficiency is decreased with increasing reaction time. When the BP concentration in pretreatment solution is increased, the grafting degree is increased to a maximum, and is then reduced. The most suitable reaction temperature is 90 °C. Grafting degree can reach the quite high value of 10.6 wt% under the conditions of BP concentration 1.0 wt%, reaction time 1 h and temperature 90 °C. © 2000 Society of Chemical Industry     

碳纤维表面的XPS表征

较详细介绍了ＸＰＳ技术在碳纤维表面化学表征中的应用。ＸＰＳ作为一种新型表面分析手段，能够给出碳纤维经不同的表面处理方法处理后纤维的表面化学组成及其结构信息，有助于了解碳纤维和聚合物树脂间的键合机理，改善纤维与树脂间的粘接性能。     

PBO纤维表面处理对EP/PBO复合材料性能的影响

通过自制的专用处理剂处理聚对苯撑苯并双恶唑(PBO)纤维表面,制备了环氧树脂(EP)/PBO纤维复合材料。通过傅立叶变换红外光谱仪和X射线光电子能谱仪对PBO纤维表面状态进行分析,采用扫描电子显微镜对经过剪切性能测试的NOL环试样破坏面形貌进行分析。结果表明,经过专用处理剂C处理后的PBO纤维表面浸润性得到提高,C、O、N三种元素的含量有较大变化,NOL环试样的剪切强度由文献中报道的15～18 MPa提高到27.83MPa,提高了约59%。     

Structure and adhesion properties of acrylic acid grafted high‐density polyethylene powders synthesized by a novel photografting method

A novel photografting, nonvapor, and nonliquid phase living graft polymerization was developed to functionalize high‐density polyethylene (HDPE) powder. The structure and adhesion properties of HDPE powder grafted with acrylic acid (AA) were studied by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), water contact angle, peel strength, and graft degree measurements. The result shows that HDPE powder can be grafted with AA via the method with a short reaction time and a high monomer conversion. The graft degree increases with the reaction time. Then, the hydrophilicity of the grafted HDPE powder increases also. The peel strength of HPDE/steel joint improved significantly when acrylic acid grafted HPDE powder was used as hot melt adhesive in place of ungrafted HDPE powder. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Photoinitiated grafting of methyl methacrylate on highly oriented polyethylene: Effect of draw ratio on grafting

Modification of highly oriented polyethylene was performed using a photoinitiated grafting technique. The samples were first coated with photoinitiator and then exposed to methyl methacrylate vapor under UV light (λ > 290 nm) at 60°C. The extent of grafting was studied as a function of draw ratio. It was found that the extent of grafting decreased significantly as the draw ratio was increased. Control samples of undrawn samples with different thermal histories suggested that there was another factor in addition to crystallinity that influences the extent of grafting. It is proposed that amorphous orientation or taut-tie molecules reduce the photoinitiation process. Gravimetric and attenuated total reflectance-IR measurements indicated that the grafting reaction can occur below the sample surface (or internal grafting) and that the proportion of surface grafting increases with increasing draw ratio. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 465–470, 1998