溶剂热法制备AS接枝马来酸酐的研究

以马来酸酐(MAH)为单体、苯乙烯(St)为共单体、过氧化二异丙苯(DCP)为引发剂,采用溶剂热法分别制备了苯乙烯-丙烯腈共聚物(AS)接枝物AS-g-MAH以及AS-g-(MAH-St).利用红外光谱对接枝物进行了结构表征,证明MAH已经成功接枝在AS链上.并用反式滴定法测定了接枝率,讨论了引发剂用量、马来酸酐用量、反应温度、反应时间、反应物浓度和共单体用量对接枝率的影响.结果表明:随着引发剂用量的增加和反应时间的延长,接枝率先增大,然后趋于平稳;随着马来酸酐用量、反应温度和反应物浓度的增加,接枝率先增大后下降;共单体苯乙烯的加入对接枝率的提高有很大的促进作用.     

双单体固相接枝聚丙烯技术研究

以马来酸酐和苯乙烯为单体,采用固相接枝法将单体接枝到聚丙烯上;考察了反应温度、反应时间、引发剂用量、溶胀时间、粒径、单体物质的量比对接枝率的影响;红外光谱分析产物结构.结果表明:马来酸酐和苯乙烯接枝到聚丙烯上;最佳条件下接枝率为9.6%.     

苯乙烯/马来酸酐接枝聚乙烯蜡的研究

用溶液法制备了马来酸酐和马来酸酐/苯乙烯双单体接枝的聚乙烯蜡,考察了反应时间、温度、引发荆、单体用量对产物接枝率的影响.结果表明二叔丁基过氧化物是一种优良的接枝反应引发剂,在ω(引发剂)=0.4%、ω(马来酸酐)=6.0%、ω(苯乙烯)=4.0%、反应温度143℃、反应时间2.5 h的条件下,聚乙烯蜡接枝率为3.4%.并对产品进行了红外光谱分析、热分析表征.     

聚丙烯（PP）／黏土复合材料熔融剂的研究

以马来酸酐（MAH）等为单体接枝聚丙烯作为聚丙烯（PP）／黏土复合材料熔融剂,考察了马来酸酐用量、引发剂过氧化苯甲酰（BPO）用量、反应时间、温度等因素对产物接枝率的影响,并通过红外光谱图对PP-g-MAH进行表征。结果表明,当m（PP）：m（复配单体）：m（BPO）=10．0：2．0：0．6、反应温度控制在120℃左右、复配单体为马来酸酐／苯乙烯时,熔融剂PP-g-MAH的接枝率可获得较大值3．9％。实验同时表明,反应时间对接枝率的影响不大;苯乙烯的加入对接枝率有较大的影响,与普通单体单一马来酸酐相比,加入苯乙烯的接枝率明显提高。     

纳米二氧化硅颗粒表面接枝改性的研究

本工作选择马来酸酐和苯乙烯单体在纳米二氧化硅粒子表面进行接枝改性,首先对纳米粒子进行烷基化处理,引入双键,然后引发聚合,使得马来酸酐和苯乙烯与纳米粒子之间形成化学键合。详细研究了各种聚合条件(引发剂浓度、单体加入量的比例、反应温度等)对接枝效果的影响,认为烷基化改性后的纳米二氧化硅粒子在聚合体系中充当极性溶剂中心的作用,控制马来酸酐和苯乙烯在粒子表面的接枝。     

马来酸酐接枝聚丙烯胶粘剂的合成研究

马来酸酐接枝聚丙烯是一种新型高分子粘合材料 ,其性能取决于马来酸酐在聚丙烯上的接枝率。在以溶剂法进行共聚合时 ,反应温度和引发剂浓度对马来酸酐接枝率有强烈的影响 ,实验表明 ,在温度≤ 10 0℃时 ,马来酸酐接枝率≤ 0 .2 %。在 13 5℃和引发剂用量 3 .0wt%时其接枝率为 1.19% ,同时单体用量对接枝率也有影响。     

线性低密度聚乙烯反应挤出接枝马来酸酐的研究

以过氧化二异丙苯(DCP)为引发剂,在双螺杆挤出机中进行了马来酸酐(MAH)熔融接枝线性低密度聚乙烯(LLDPE)的研究,用红外光谱表征了接枝反应的存在。考察了引发剂用量、单体用量、螺杆转速以及温度对接枝反应的影响,并探讨了苯乙烯(St)作共单体对接枝反应的影响。研究表明:在引发剂含量较低时,用苯乙烯作共单体能够显著提高接枝率。     

马来酸酐熔融接枝全同聚1-丁烯

采用马来酸酐(MAH)熔融接枝全同聚1-丁烯,研究了MAH及第二单体苯乙烯(St)、复配引发剂、温度对接枝率的影响,用傅里叶变换红外光谱法表征接枝产物。结果表明:2种单体和复配引发剂用量对接枝率有较大影响,加入St提高了接枝率,引发剂过氧化二异丙苯与过氧化二苯甲酰质量比为3:1时接枝率最高,接枝率随着温度的升高而增大。     

MAH溶液法接枝SBS的研究

采用马来酸酐（MAH）作为接枝单体,对苯乙烯—丁二烯—苯乙烯三嵌段共聚物（SBS）进行溶液接枝。研究了反应温度、反应时间、马来酸酐用量、引发剂种类及用量对接枝率的影响。得到最佳反应条件为：m（SBS）/m（MAH）/m（BPO）/m（溶剂）=100：10：0.8：400,反应温度75℃。反应时间3 h;红外光谱图证实了接枝物的生成。     

马来酸酐苯乙烯双单体接枝聚丙烯的研究

研究了聚丙烯（ＰＰ）采用熔融法接枝马来酸酐（ＭＡＨ）聚乙烯（Ｓｔ）双单体。实验表明,马来酸酐接枝率随其加入量增加而提高;添加两种单体时,马来酸酐添加量保持不变,马来酸酐接枝率随苯乙烯添加量增加而提高。经转矩流变,红外,热失重和差示扫描量热分析表明：马来酸酐,苯乙烯均与聚丙烯发生接枝反应,且有交联网络出现,因此推断出苯乙烯和马来酸酐预先发生交替共聚,共聚物与聚丙烯反应生成最终接枝物。接枝物应用于ＰＰ     

超临界CO2协助马来酸酐对聚丙烯的接枝共聚

利用超临界流体插嵌技术协助苯乙烯和马来酸酐共单体对聚丙烯膜进行接枝改性。在制备过程中采用“两步法”,有利于研究超临界CO2的溶胀、渗透和携带作用,并且能够控制成本。临界CO2的插嵌压力、插嵌温度以及引发剂浓度是影响接枝率的主要因素。在压力10 MPa、温度42℃条件下,接枝率具有极大值,约为4.7%。对接枝前后聚丙烯膜的FT-IR、DSC、SEM表征,进一步证明了共单体确实接枝在聚丙烯膜基质上,并且随着接枝率的提高,接枝聚丙烯膜的表观结晶度和熔点均下降。     

Ultrasonic induced grafting of maleic anhydride onto polypropylene in melt state

This paper presented a model study on maleic anhydride (MAH) grafted polypropylene (PP) performed in melt state through ultrasonic initiation without any chemical initiator and solvent. The structures of PP-g-MAH were characterized by FTIR and ¹³C NMR and the mechanism were discussed. The graft degree (G) was determined by titration using a solution of organic base tetra-butyl ammonium hydroxide (TBAOH) in ethanol, and the effects of ultrasonic intensity, MAH concentration and styrene (St) on G and graft efficiency (G _E ) of MAH were investigated. Results showed that MAH was successfully grafted onto the PP chain and the optimum conditions for grafting were at an ultrasonic intensity of 300 W with a MAH concentration of 25 wt.%, and the maximum G of MAH of 3.34 wt.% was obtained when the molar ratio of St to MAH was 1:1. DSC and XRD were also employed to determine the thermodynamic performance and crystalline structures of the products.     

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     

马来酸酐接枝聚丙烯的研究

研究了聚丙烯(PP)与马来酸酐(MAH)的接枝配方;并且探索了接枝反应过程中PP自由基的降解抑制方法。结果表明,以引发剂A为引发剂,以嵌段PP为基础树脂,以MAH为接枝单体,以St为第二单体的PP／A／St/ MAH反应体系使PP自由基降解得到了有效的抑制,可制备接枝为1．5％-4．0％的接枝聚丙烯。     

Synthesis of multifunctional polypropylene via solid phase cografting and its grafting mechanism

Functional monomers, maleic anhydride (MAH) and vinyl acetate (VAc), were used as comonomers in the solid‐phase grafting of polypropylene (PP). Quantitative determination of the graft level of both MAH and VAc performed by titration and FTIR methods allowed for a good appreciation of the interaction of MAH and VAc. A product with high‐graft level of both VAc and MAH was obtained when the feeding molar ratio of MAH/VAc approached 1 : 1. The melt flow rate (MFR) of the grafted PP decreased with the increase in the feeding amount of VAc. It was proposed that MAH and VAc molecules could form a kind of stable transition state during the graft polymerization and that the reactivity of both monomers were enhanced. The resulting multifunctional PP offers possibility for the development of novel PP‐based polymer blends and composites, thus extending the application field of PP. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 929–935, 2002; DOI 10.1002/app.10121     

Styrene‐assisted free‐radical graft copolymerization of maleic anhydride onto polypropylene in supercritical carbon dioxide

The free‐radical graft copolymerization of maleic anhydride (MAH) onto polypropylene (PP) with the assistance of styrene (St) in supercritical carbon dioxide (CO₂) was studied. The effects of the St concentration and initiator concentration on the functionality degree of the grafted PP in supercritical CO₂ were investigated. The addition of St drastically increased the MAH functionality degree, which reached a maximum when the molar ratio of MAH and St was 1:1. St, an electron‐donating monomer, could interact with MAH through charge‐transfer complexes to form the St–MAH copolymer (SMA), which could then react with PP macroradicals to produce branches by termination between radicals. There was SMA in the grafting reaction system characterized by Fourier transform infrared and differential scanning calorimetry. Furthermore, the highest MAH functionality degree was obtained when the concentration of 2,2′‐azobisisobutyronitrile (AIBN) was 0.6 wt % based on PP. The effects of the temperature and pressure of supercritical CO₂ on the functionality degree of the grafted PP were analyzed. An increase in the temperature accelerated the decomposition rate constant of AIBN, thereby promoting the grafting reaction. In addition, an increase in the temperature increased the diffusion of monomers and radicals in the disperse reaction system of supercritical CO₂. The highest degree of functionality was found at 80°C. Also, the functionality degree of grafted PP decreased with an increase in the pressure of supercritical CO₂ within the experimental range. The morphologies of pure PP and grafted PP were significantly different under polarizing optical microscopy. The PP spherulites were about 38 μm in size, and the grafted PP spherulites were significantly reduced because of heterogeneous nucleation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 853–860, 2003     

聚丙烯熔融接枝改性研究

采用熔融接枝的方法,研究了多组分体系下不同单体熔融接枝聚丙烯的性能。结果表明:在共单体苯乙烯、引发剂和聚丙烯相同的条件下,接枝物的极性均较未接枝的聚丙烯极性增加;不同单体所得接枝物的接枝率不同;熔体流动速率的降低使接枝物的加工性能有不同程度的下降。接枝物极性增加的趋势依次按接枝单体MAH、MMA、GMA递增。接枝物的偏光显微镜分析表明,接枝支链的生成可以促进聚丙烯的异相成核,使晶粒细化。     

相容剂马来酸酐-苯乙烯接枝聚丙烯的制备及性能研究

研究单体用量、引发剂用量、反应温度、反应时间对熔融接枝法制备的马来酸酐-苯乙烯接枝聚丙烯(PP-g-(MAH-co-St))的接枝率(GMAH)、熔体流动速率(MFR)和拉伸强度的影响,并通过红外光谱图对PP-g-(MAH-co-St)进行表征。结果表明:当PP:MAH:St:DCP质量分数比为100:6:6:0.4,反应温度为180℃,反应时间为3 min时,接枝物的GMAH达1.51%,MFR达55.28 g/10min,拉伸强度为26.72 MPa;红外分析表明:MAH和St与已接枝到PP上。     

GMA/St双组分单体熔融接枝聚丙烯的研究

分别以甲基丙烯酸缩水甘油酯（GMA）和马来酸酐（MAH）为接枝单体，苯乙烯（St）为接枝共单体，过氧化二异丙苯（DCP）为引发剂对聚丙烯（PP）进行熔融接枝，研究了接枝单体的种类、组分配比等因素对PP的接枝率和熔体流动速率等的影响，并研究了接枝PP的力学性能和耐热变形性能。实验结果表明：作为接枝单体，GMA比MAH更具有优越性；双组分单体熔融接枝PP的接枝率和性能优于单组分单体熔融接枝；接枝PP的结晶参数受其接枝率的影响；当PP／GMA／St／DCP=100／6／3／0、3时，PP—g^-（GMA—CO—St）的接枝率最高，力学性能和耐热变形性能最好。