聚乙烯固相接枝马来酸酐的研究

研究了以过氧化苯甲酰（ＢＰＯ）为引发剂,二甲苯为界面剂,粉状聚乙烯（ＨＤＰＥ、ＬＬＤＰＥ）固相接枝马来酸酐（ＭＡＨ）的反应。讨论了反应温度、引发剂用量、单体用量和界面剂种类等对接枝反应的影响,并用红外光谱法证实了接枝反应。结果表明,ＰＥ固相接枝ＭＡＨ反应对温度敏感,随温度升高,接枝率提高;在一定范围内,接枝率随引发剂用量、单体用量和搅拌转速、界面剂用量的增加而提高;界面剂用量虽少,但能促进ＢＰＯ、ＭＡＨ在ＰＥ上的反应。通过接枝反应可得到接枝率为９％左右的ＰＥ－ｇ－ＭＡＨ产物和接枝率为１３％以上的ＬＬＤＰＥ－ｇ－ＭＡＨ产物     

甲基丙烯酸固相接枝聚丙烯及其增容研究

本文研究了甲基丙烯酸固相接枝聚丙烯及其增容效果。讨论了反应温度、反应时间、引发剂ＢＰＯ浓度、单体ＭＡＡ浓度对接枝率的影响，接枝物用红外光谱进行表征。结果表明：当实验条件在反应时间为２．５ｈ，反应温度为１１５℃，ＢＰＯ用量为１．５％、ＭＡＡ／ＰＰ为０．２０／１时，可获得最大接枝率１２．５％。红外光谱分析证明ＰＰ已接枝上ＭＡＡ，得到了ＰＰ－ｇ—ＭＡＡ接枝共聚物。固相接枝ＰＰ－ｇ－ＭＡＡ可作为ＰＰ－高岭土复合材料的增容剂，它明显改善了两相的相间结合，改善了复合材料的力学性能。     

聚丙烯接枝甲基丙烯酸的合成与性能研究

本文以二甲苯（ＤＭＢ）为溶剂，过氧化二苯甲酰（ＢＰＯ）为引发剂，采用溶液聚合的方法，在一定条件下使甲基丙烯酸（ＭＡＡ）与等规聚丙烯（ＩＰＰ）发生接枝共聚制得接枝物。红外光谱证实了接枝物ＩＰＰ－ｇ－ＭＡＡ的存在。实验表明：反应温度、反应时间和单体浓度对接枝共聚反应影响很大。当反应温度在１００℃以下时，随反应温度的增加，接枝率显著增大；而反应温度高于１００℃以后，提高温度接枝率呈下降趋势。延长反应时间可以提高接枝率，反应２ｈ后则接枝率增加缓慢趋于稳定。ＭＡＡ单体浓度较低时，接枝率随单体浓度增大而增加；当其浓度大到某一数值时（本实验为０．４９ｍｏｌ／Ｌ），接枝率达到一极值，随后下降。从偏光显微镜观察，接枝共聚后的ＩＰＰ－ｇ－ＭＡＡ仍呈晶体形貌，当接枝率低于一定数值时（本实验为１９．６％），晶体细而规整，有球晶特征，随着接枝率的增加，晶体有增大趋势，规整程度降低。结晶速率随着接枝率的增加而增大     

LLDPE溶液接枝马来酸酐的研究

研究了在二甲苯溶剂中，以过氧化二苯甲酰（ＢＰＯ）为引发剂，线性低密度聚乙烯（ＬＬＤＰＥ）接酸酐的反应，采用正交实验方法考察了引发剂用量，单体及ＰＥ浓度。反应温度及时间、阻止交联剂的加入量等因素对接枝反应的影响。结果表明，各因素对ＰＥ接枝率影响的大小次序是ＭＡＨ用量，反应温度、阻止交联剂用量、ＬＬＤＰＥ浓度和ＢＰＯ有用量，阻止交联剂的加入可以有铲地防止ＰＥ恶性循环 自由基的交联。     

PE—MAH的合成及其对PE／NBR的增容作用

聚乙烯（ＰＥ），马来酸酐（ＭＡＨ）和过氧化二异丙苯（ＤＣＰ）在溶液中反应，其产物经多次纯和红外光谱分析证明，ＭＡＨ以化学链连接到ＰＥ分子链上，接枝率达０．５ＭＡＨ／１００Ｅ，即相当平均每个ＰＥ上接枝有１０个ＭＡＨ。用不同接枝率的聚乙烯接枝马来酸酐聚物（ＰＥ－ＭＡＨ）作为极性差别较大的ＰＥ和丁腈橡胶（ＮＢＲ）的相容剂，分别研究其接枝率和用量对共混物的拉伸强度和低温冲击强度的影响，结果发现：ＰＥ－ＭＡ     

PEA－PBA－g－PST热塑性弹性体的合成及性能

以丙烯酸丁酯（ＢＡ）、丙烯酸乙酯（ＥＡ）、聚苯乙烯大分子单体（ＰＳＴ）合成了一种三元接枝多相共聚物。研究了单体总浓度、聚合时间、大分子单体在单体混合物中的质量百分数、溶剂、小分子单体的摩尔比等对大分子单体接枝效率的影响。用ＩＲ、ＵＶ、ＰＧＣ等仪器研究了聚合物的结构。测定了聚合物的力学性能，并考察了对接枝共聚物力学性能的影响因素。     

EPDM－g－MMA接枝率对POM／EPDM共混物增容作用的影响

本文介绍以ＢＰＯ为引发剂，合成接枝共聚物ＥＰＤＭ－ｇ－ＭＭＡ的方法。并对其进行红外表征，另外，借助ＳＥＭ和力学性能测试研究了接枝率对ＰＯＷ／ＥＰＤＭ共混物的增容作用的影响。     

SBS／MMA—BA自交联型接枝共聚物及其性能研究

在交联单体Ｎ－ＭＭＡ存在下，研究了ＳＢＳ／ＭＭＡ－ＢＡ四元枝共聚反应及其产物性能，讨论了引发剂浓度、Ｎ－ＭＭＡ用量、单体配比、反应时间及反应温度对接枝聚合影响，获得了最佳合成工艺条件。通过红外光谱和ＰＶＣ／ＳＢＳ粘接性能测试表明，共聚物具有初粘力大、剥离强度高、使用方便等特点。     

LLDPE熔融接枝丙烯酸及其应用的研究

以丙烯酸（ＡＡ）为接枝单体在Ｂｒａｂｅｎｄｅｒ中对ＬＬＤＰＥ进行熔融接枝改性研究，考察了共混温度、过氧化二异丙苯（ＤＣＰ）用量、ＡＡ用量以及混合时间对接枝率的影响，结果表明控制适当的反应条件率可达９％，而且反应温度以２２０℃左右为宜，ＤＣＰ用量不宜过高，以免引起严重的交联反应，研究ＬＬＤＰＥ－ｇ－ＡＡ对ＬＬＤＰＥ／淀粉可降解体系的增容效果表明，接枝物提高了ＬＬＤＰＥ／淀粉体系的拉伸强度，并且与淀粉     

聚乙烯接枝马来酸锌离聚体对PC／PS体系增容作用的研究

本文用ＤＳＣ和ＳＥＭ等方法研究了不同接枝率、不同加入量的聚乙烯接枝马来酸锌（ＰＥｇ－ＭＡＺｎ）离聚体对ＰＣ／ＰＳ体系增容作用的影响。结果表明,在一定范围内ＰＥ－ｇ－ＭＡＺｎ接枝率越大、加入量越多对ＰＣ／ＰＳ体系的增容效果越好。     

Grafting of methyl methacrylate onto cellulose nitrate initiated by benzoyl peroxide

It has been observed that grafting of vinyl monomers onto cellulose nitrate in solution takes place using benzoyl peroxode. The graft copolymer was isolated from the unreacted backbone and homopolymer by selective solvent extraction. The effect of variables, such as the initiator concentration, the monomer concentration and the reaction time on the percent grafting and the grafting efficiency, were discussed. A probable mechanism for grafting of vinyl monomers to cellulose nitrate in solution has been proposed.     

Radiation‐induced graft copolymerization of α‐methyl styrene and butyl acrylate mixture into polyetheretherketone films

Radiation‐induced graft copolymerization of α‐methyl styrene (AMS), butyl acrylate (BA) monomers, and their mixture was investigated on poly(etheretherketone) films. The graft polymerization was carried out using ethyl methyl ketone as the medium for the copolymerization and the maximum degree of grafting of 27% was achieved. It was observed that the grafting is significantly influenced by the reaction conditions, such as reaction time, preirrradiation dose, monomer concentration, monomer ratio, and the reaction temperature. The degree of grafting increases as the monomer concentration increases up to 30%, beyond which a decrease in the grafting was observed. The degree of grafting showed a maximum at 40% BA content in the monomer mixture. The temperature dependence of the grafting process shows decreasing grafting with the increase in the reaction temperature. The presence of AMS and BA grafts in the film was confirmed by FTIR spectra. The relative change in the PBA/PAMS fraction with respect to the reaction temperature has been found in this study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Maleic anhydride/styrene melt grafting and crosslinking onto ethylene‐octene copolymer

Melt grafting of the multimonomer system of maleic anhydride (MAH)/styrene (St) onto ethylene‐octene copolymer (POE) was performed by a twin‐screw extruder. The effects of St and initiator contents as well as MAH/St on the grafting reaction were investigated. The structure and properties of the grafted POE were characterized by the Fourier transform infrared spectroscopy, melt flow index, dynamic rheological behaviors, and thermogravimetric analysis. It is shown that the addition of St can significantly enhance MAH grafting degree onto POE. MFI values of grafted POE are affected not only by MAH/St copolymer concentration, but also by initiator concentration. These data indicate that the interaction and reaction between MAH and St monomers plays an important role in the grafting reaction. St improves the grafting reactivity of MAH and reacts with MAH before the two monomers graft onto POE. And high grafting degree can be obtained while the gel content is still low. Compared with neat POE, grafted POE shows different dynamic rheological behaviors and high thermal stability. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Radiation grafting of hydrophilic monomers onto poly(4-methylpentene-1), II. Grafting of long chain monomers and physical properties of the grafted films

Radiation grafting of 2-hydroxyethyl methacrylate (HEMA) and methoxytetraethyleneglycol methacrylate (M4G) on low crystallinity poly(4-methylpentene-1) (TPX) has been investigated. Grafting yield increased with increasing pre-irradiation dose, grafting temperature, and monomer concentration. Grafting rate depends on length of molecular chain in the monomers and decreases with increasing chain length. The grafting yields of electron beam irradiated samples were higher than those of γ-irradiated ones because of higher radical concentration. Tensile strength of the grafted film in the dried state increased and the elongation at break decreased with increasing degree of grafting. On the other hand, in the wet state, the tensile strength and elongation at break decreased with increasing the degree of grafting due to the lack of hydrogen bonds between the grafted chains caused by increased water absorption.     

官能化乙丙橡胶的制备和表征

用２,５－二甲基－２,５－二叔丁基过氧基己烷为引发剂,甲基丙烯酸环氧丙酯（ＧＭＡ）、马来酸酐（ＭＡＨ）和丙烯酸（ＡＡ）为接枝单体,对三元乙丙橡胶（ＥＰＤＭ）和二元乙丙橡胶（ＥＰＲ）进行熔融接枝,接枝产物用ＦＴＩＲ、１３Ｃ－ＮＭＲ等进行了表征,并用化学滴定方法对接枝率进行了测定。实验结果表明,影响接枝率和凝胶质量分数的主要因素为乙丙橡胶的化学结构、引发剂和单体的用量、反应时间及温度等。接枝单体反应活性大小依次为ＧＭＡ,ＡＡ,ＭＡＨ。     

Kinetic study on free radical grafting of polyethylene with acrylic acid by reactive extrusion

In the reactive extrusion process for the free radical grafting of acid monomers onto polyethylene, monomer grafting and homopolymerization occur simultaneously and interact with each other. Using an incremental theory, mathematical models of conversions for monomer grafting and homopolymerization were separately constructed to predict the grafting degree, mass of homopolymer and grafting efficiency. Effects of the barrel temperature, initial monomer and initiator concentrations on grafting behaviors were investigated. The barrel temperature and initial monomer concentration were shown to be the main process parameters for controlling the grafting degree. The grafting degree and mass of homopolymer increased significantly with increasing barrel temperature and monomer concentration and increased marginally with increasing initiator concentration. No significant improvement in the grafting efficiency was observed. The predictions of the models are in good agreement with experimental data. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40990.     

Grafting of 2-hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers

Grafting of 2-hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers, initiated by the bisulfite/pesulfate redox system, has been investigated. Using the method of statistical planning of experiments, regression equations have been obtained describing the effects of the monomers concentration and the composition of the initiating system on the monomers conversion, degree of grafting and on physical properties of grafted collagen. The relationship between the polyacrylate content in the composites prepared and their swelling ability, water absorption capacity, and the tensile strength is discussed.     

Ionic Xanthate Method of Grafting. II

In the ionic xanthate method of grafting, the increase of sodium hydroxide concentration and liquor ratio increased the grafting parameters up to a limit. The limit varied from one monomer to another. The positive values of the standard degree of concentration of sodium hydroxide indicate that the graft polymerization reaction has happened. The extent of decrease in the grafting parameters with the increase of the liquor ratio may be due to an increase of termination reactions as a result of the increasing number of HOH molecules, with resulting chain transfer reactions to solvent. Grafting parameters also increased with an increase of the concentration of monomers up to a limit. The reactivity of these monomers is in the order: methyl methacrylate > ethyl acrylate > allyl chloride > acrylonitrile > methyl acrylate > allyl alcohol, being dependent on both the radical stabilization and the strength of the electron acceptance of the monomers. The activation energy of the overall polymerization reaction (i.e., grafting and homopolymer) decreased with the increase of the crude grafting yield, and the reverse relation was achieved with the true grafting yield (i.e., grafting reaction only). This difference may contribute to the difference in the conformation of the polymer chains in graft polymerization on the active sites of the cellulose chains.     

Ionic Xanthate Method of Grafting. II

In the ionic xanthate method of grafting, the increase of sodium hydroxide concentration and liquor ratio increased the grafting parameters up to a limit. The limit varied from one monomer to another. The positive values of the standard degree of concentration of sodium hydroxide indicate that the graft polymerization reaction has happened. The extent of decrease in the grafting parameters with the increase of the liquor ratio may be due to the increase of the termination reactions as a result of increasing the number of HOH molecules and the consequent chain transfer reactions to solvent. Grafting parameters also increased with the increase of the concentration of monomers up to a limit. The reactivity of these monomers is in the order: methyl methacrylate > ethyl acrylate > allyl chloride > acrylonitrile > methyl acrylate > allyl alcohol, being dependent on both the radical stabilization and the strength of the electron acceptance of the monomers. The activation energy of the overall polymerization reaction (i.e., grafting and homopolymer) decreased with the increase of the crude grafting yield, and the reverse relation was achieved with the true grafting yield (i.e., grafting reaction only). This difference may be attributed to the difference in the conformation of the polymer chains to graft polymerize on the active sites of the cellulose chains.     

顺丁烯二酸酐及其衍生物溶液接枝改性聚苯乙烯的研究

文章介绍了分别将顺丁烯二酸酐，顺丁烯二酸一丁酯和顺丁烯二酸二丁酯与聚苯乙烯的二甲苯溶液在过氧化二苯甲酰引发下的接枝反应，讨论了反应单体浓度、引发剂用量接枝率的影响，测试了接枝物的成膜性能。