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。     

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     

马来酸酐及苯乙烯同时接枝聚丙烯的研究

用过氧化二异丙苯(DCP)作为引发剂，采用双螺杆反应挤出的苯乙烯、马来酸酐2种单体同时接枝聚丙烯．研究了单体总浓度、单体比例、引发剂浓度对PP的接枝率、接枝效率和熔体流动速率的影响。通过实验发现苯乙烯的加入使接枝率和接枝效率比单独的马来酸酐接枝都有很大的提高。     

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     

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.     

Melt grafting of maleic anhydride onto polypropylene with 1‐decene as a second monomer

The influence of 1‐decene as the second monomer on the melt‐grafting behavior of maleic anhydride (MAH) onto polypropylene (PP) was studied with differential scanning calorimetry and Fourier transform infrared spectroscopy. We found that the value of the grafting degree increased from 0.68% for pure MAH‐g‐PP to 1.43% for the system with a 1‐decene/MAH molar ratio of 0.3, whereas the maximum value with styrene (St) as the second monomer was 0.98% under an St/MAH molar ratio of 1.0. Compared with the contribution of St/MAH‐g‐PP to the peeling strength between the PP and polyamide (PA) layer for a PP/PA laminated film, the introduction of 1‐decene/MAH‐g‐PP increased the peeling strength from 180 g/15 mm to 250 g/15 mm. 1‐Decene inhibited the chain scission behavior of PP. 1‐Decene reacted with MAH to form a 1‐decene/MAH copolymer or the Alder‐ene reaction product before the two monomers grafted onto PP. The grafting of the reactive product onto PP greatly improved the grafting degree of MAH. What is more, because of the similar chemical structures of 1‐decene and PP, the affinity of 1‐decene with PP was higher than that of St. Compared with St, the introduction of less 1‐decene led to a higher grafting degree and higher peeling strength. Therefore, we concluded that 1‐decene was more effective for improving the grafting degree of MAH onto PP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚丙烯——马来酸酐／聚己内酯三元接枝物的合成及其热分析研究

采用熔融法合成了聚丙烯—马来酸酐／聚己内酯（ＰＰ－ｇ－ＭＡＨ／ＰＣＬ）三元接枝共聚物。用富里叶红外光谱（ＦＴＩＲ）表征了接枝共聚物的化学结构,用峰高法测定了产物的接枝率。同时,考察了接枝反应时间和ＰＣＬ的分子量对接枝率的影响。并以示差扫描量热法（ＤＳＣ）对其热性能进行了分析。结果表明,ＰＣＬ的引入及其接枝率对ＰＰ－ｇ－ＭＡＨ的热性质有一定的影响,但分子量较低时将导致此接枝共聚物的结晶度和熔融温度进一步下降。     

多单体固相接枝聚丙烯

用乙醚作分散剂,将接枝单体和引发剂均匀分布到聚丙烯(PP)粒子表面,改善相间传质;以偶氮二异丁腈为引发剂,用固相接枝方法制备了丙烯酸丁酯(BA)-马来酸酐(MAH)-苯乙烯(St)接枝PP。考察了接枝单体用量、引发剂用量、反应温度及时间、界面剂用量等对接枝的影响,用傅里叶变换红外光谱仪、热重分析仪和扫描电子显微镜等对接枝产物进行了表征。结果表明:使用分散剂消除了普通固相反应出现的结块现象,接枝单体分布比较均匀;PP为20.0 g时,n(BA)/n(MAH)/n(St)为2:1:1,接枝单体质量分数为6%,引发剂质量分数为0.3%,在80℃反应1.5 h,得到了接枝率为3.48%的接枝产物;产物的拉伸强度没有变化,但极性和热稳定性得到提高。     

两亲性接枝共聚物PVA-g-PBA的合成与表征

以过硫酸钾 (KPS)为引发剂 ,将丙烯酸丁酯 (BA)接枝到聚乙烯醇 (PVA)上 ,制得两亲性接枝共聚物 PVA-g-PBA。用红外光谱、X射线衍射表征了接枝物 ,研究了引发剂浓度、单体浓度及反应时间对单体转化率、接枝率和接枝效率和接枝率对共聚物吸水性能的影响。结果表明在水介质中 ,氮气保护下 ,70℃时 ,以过硫酸钾 (KPS)为引发剂 ,将丙烯酸丁酯 (BA)接枝到聚乙烯醇 (PVA)上 ,[PVA]为 2 .5× 1 0 -4mol/ L,[BA]为 0 .63 mol/ L、[KPS]为 5 .5 5× 1 0 -4时 ,反应 5 h,能获得较高 CM、G和 Ge的接枝物。接枝物的接枝率越高 ,吸水率越低 ,吸水 1 0 h达平衡 ,最大平衡吸水率为 1 88.8%。     

聚丙烯固相接枝马来酸酐的研究

用固相接枝法在聚丙烯(PP)分子链上接枝马来酸酐(MAH),制备功能化聚丙烯。重点讨论了反应时间和反应温度以及单体浓度和引发剂浓度对接枝产物PP-g-MAH接枝率的影响。在其他条件不变的情况下,当反应时间为2h,反应温度为120℃,单体与PP的质量比为1∶1,引发剂用量为2.5%时,最大接枝率可达到1.6%。采用红外光谱表征了PP-g-MAH。     

POE/PP的接枝改性及在制备超韧尼龙中的应用研究

研究了在含有适量聚丙烯的聚烯烃弹性体乙烯-1-辛烯共聚物(POE)熔融接枝马来酸酐(MAH)反应中,引发剂、接枝单体用量、及阻交联剂品种对接枝率的影响及其微观机理。结果表明:控制体系引发剂的含量是获取高接枝率的关键,当DCP的加入量为0.25%,MAH的含量为1.2%时,体系的接枝率达1%左右,从熔体流动速率来看体系未出现明显交联。同时探讨了接枝物在超韧尼龙合金制备中的应用效果。     

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。     

吸水膨胀弹性体PVA-g-PBA的研究

在水介质中.在氮气保护下以硝酸铈铵(CAN)为引发剂,将丙烯酸丁酯(BA)接枝到聚乙烯醇(PVA)上,制得水膨胀弹性体PVA—g—PBA。通过红外光谱证实了接枝物的形成。讨论了PVA浓度、单体浓度、引发剂浓度和反应温度对接枝物接枝率(G％)的影响。结果表明随PVC浓度增大,接技率降低.[PVA2.5×10-4mol/L.[BA]0.702mol/l、[CAN]0.01mol/L45℃接枝率较高.接枝率越高其吸水膨胀率越低,8h达吸水平衡,最大吸水率为165.1％。     

(E/VAC)-g-MAH对PP/PBT共混体系的增容改性

以过氧化苯甲酰(BPO)为引发剂,通过熔融接枝法在Brabender转矩流变仪中制得马来酸酐接枝(乙烯/乙酸乙烯酯)共聚物[(E/VAC)-g-MAH]。将该接枝物用于增容聚丙烯/聚对苯二甲酸丁二酯(PP/PBT)共混体系。结果表明,在(E/VAC)-g-MAH的作用下,PP/PBT共混物的力学性能得到提高,界面形貌得到改善,体系的相容性得到明显增强。     

马来酸酐溶液法接枝聚丙烯的探讨

采用溶液法制备了马来酸酐接枝聚丙烯。采用单因素及正交实验方法研究了单体、引发剂用量、反应温度、反应时间、溶剂用量及引发剂加入工艺等因素对产物接枝率的影响。结果表明,各因素对聚丙烯接枝率都有一定的影响,马来酸酐及二甲苯的用量对聚丙烯接枝率影响最大,当马来酸酐、二甲苯与聚丙烯之间比例为0.1/2/1时,聚丙烯的接枝率最大,接枝率可达4.36%。     

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。     

STUDY ON THE GRAFT REACTION OF MALEIC ANHYDRIDE ONTO METALLOCENE-BASED POLYETHYLENE–OCTENE ELASTOMER

Grafting of maleic anhydride (MAH) onto metallocene based polyethylene–octene elastomer (POE) was studied in this article. By the results of Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry (DSC), it was confirmed that POE was grafted with MAH but the crosslinking reaction was accompanied by the predominant graft reaction due to a competition of POE macro-radical and excited MAH. Effects of various parameters such as monomer loading, initiator loading, and reaction time on grafting percentage and gel yield were also investigated. It was also found that the grafting percentage and the gel yield, at equilibrium, were both higher for POE containing lower degree of comonomer content. From the result of DSC characterization, it was shown that the change of crystallinity is slight for POE-g-MAH copolymer when the gel was removed from the copolymer. So one thought that the effect of gel formation on the properties of POE-g-MAH can be neglected due to the low gel yield. It was also proved that strength and elongation at break are both decreased while the grafting percentage was increased. Finally, the method proposed in this research can produce POE-g-MAH copolymer with low gel.     

Structure and Rheological Properties of the Products of Solid-State Graft Polymerization of Styrene in Annealed Polypropylene Reactor Granules

Solid-state grafting polymerization of styrene (St) in polypropylene (PP) reactor granules was conducted with different St load using tertiary-butyl perbenzoate as initiator. The graft copolymers showed higher weight average molecular weight than the original PP when the St load is high enough. A typical graft copolymer was fractionated into six fractions according to crystallinity, and the fractions showed similar St content. Comparing to the original PP, complex viscosity of the grafting products was significantly increased and the tan α value decreased at low frequency. Increasing the grafting degree exerts a positive effect on these changes. These phenomena prove the existence of long chain branches in the grafting products, and St played important roles in the formation of long chain branches.     

马来酸酐接枝POE改性SAN树脂的制备与性能研究

利用熔融接枝法制备了马来酸酐接枝乙烯-辛烯共聚物（POE-g-MAH），探讨了过氧化异丙苯（DCP）和马来酸酐（MAH）用量对POE—g—MAH接枝率的影响，得出了最佳的DCP和MAH用量分别为0．10份和2．0份。将不同接枝率的POE—g—MAtt与丙烯腈-苯乙烯共聚物（SAN树脂）共混，发现POE—g—MAH的接枝率越高，对POE—g-MAH／SAN体系的缺口冲击强度的提高越显著。     

Synthesis and reaction kinetics model of suspension phase grafting polypropylene with dual monomers

The grafting polymerization of maleic anhydride (MAH) and styrene (St) onto PP was carried out in suspension phase. Infrared (IR) spectra and ¹H-NMR spectra confirmed that MAH and St were successfully grafted onto the PP backbone. The influences, such as monomers concentration, reaction temperature, initiator concentration and reaction time, on the grafting polymerization rate were also studied, and then the polymerization model was obtained to describe the polymerization regularities. The results showed that the model was adequate to reflect the courses, and diffusion and equilibrium adsorption played an important role in suspension polymerization.