不同单体熔融接枝聚丙烯性能研究

采用双螺杆挤出机熔融接枝的方法,研究了多组分体系下不同单体熔融接枝聚丙烯(PP)的性能。结果表明:在共单体苯乙烯、引发剂和PP相同的条件下,接枝物的极性均较未接枝PP的极性增加,不同单体所得接枝物的接枝率不同。不同熔体质量流动速率造成接枝物的加工性能有不同程度的下降。接枝物极性的增加的趋势依次按接枝单体马来酸酐(MAH)、甲基丙烯酸甲酯(MMA)、甲基丙烯酸缩水甘油酯(GMA)递增。这说明GMA接枝聚丙烯对提高PP极性的效果最明显,MMA其次,而MAH则相对较弱。接枝物的偏光显微镜分析发现,接枝支链的生成可以促进PP的异相成核,造成晶粒细化。     

高极性PP熔融接枝物的制备及应用

采用复合引发体系、双组分熔融接枝法 ,研制开发了高极性聚丙烯接枝物。讨论了复合引发体系、共聚单体在接枝过程中的作用 ,研究了接枝物对PP/EPDM的相容性的影响。将少量接枝物与PP、EPDM、HDPE共混 ,并添加相容剂及其他助剂 ,可得到高冲击性能、可涂装性能优良的汽车保险杠材料 ,其性能达到国外同类产品指标要求     

高极性聚丙烯的制备及其应用研究

利用双组分熔融接枝极性单体的方法,制备高极性聚丙烯材料。红外光谱和熔融指数表明,采用多组分熔融接枝体系,通过加入苯乙烯单体,能够有效地控制单组分熔融接枝聚丙烯体系中严重的聚丙烯降解反应,大幅度提高极性单体的接枝率,同时保持了聚丙烯优良的力学性能,从而获得一种力学性能优良的高极性聚丙烯材料。     

多单体接枝技术的研究进展

综述了单体接枝技术的研究现状,并对共单体的选择、作用机理及多单体熔融接枝聚丙烯的增容作用进行阐述,Q-e规则成为简单并且直观的选择共单体的方法。多单体熔融接枝技术能抑制聚丙烯降解,提高接枝率,保持基体良好的力学性能。将多单体接枝物作为增容剂,有望制备出性能优良的工程材料。     

马来酸酐接枝改性聚丙烯及其在木塑复合材料中的应用

通过双螺杆挤出机聚丙烯熔融挤出接枝马来酸酐制备马来酸酐接枝聚丙烯（PP-g-MAH）;研究了接枝单体马来酸酐（MAH）、引发剂DCP及共单体St等对聚丙烯（PP）熔融接枝MAH的接枝率的影响。将制备的接枝物应用于木塑复合材料中,发现木粉与聚丙烯之间的界面结合有了明显的改善,添加的PP-g-MAH增强了木粉和聚丙烯基体之间的黏合性,使两相结合得更紧密,进而提高了木塑复合材料的力学性能。     

苯乙烯/二乙烯苯协助马来酸酐熔融接枝聚丙烯研究

采用液-固溶胀的方法将马来酸酐(MAH)、共单体[苯乙烯(St)、二乙烯苯(DVB)]和引发剂过氧化二异丙苯分散到聚丙烯(PP)颗粒内部,利用流变仪研究了共单体协助MAH熔融接枝PP反应,采用红外光谱、热重分析和水接触角对接枝物的结构及性能进行分析,并对接枝反应机理加以探讨。结果表明,在最优反应条件下,添加St时接枝物的MAH接枝率和凝胶率分别为2.25%、1.56%;添加DVB时接枝物的MAH接枝率和凝胶率分别为3.06%、46.31%,并且接枝物的热稳定性和极性均有不同程度提高;接枝机理分析认为,在接枝反应时共单体首先接枝到PP链上,有效抑制了PP的降解,并与MAH主要以共聚形式接枝到PP主链上;DVB在分子结构上比St多了一个碳碳双键,一方面显著提高MAH接枝率,另一方面明显增大接枝PP大分子自由基间双基偶合终止的机会。     

多单体熔融接枝聚丙烯的研究进展

介绍了聚丙烯(PP)多单体熔融接枝聚合技术,总结了现阶段对多单体熔融接枝PP的研究现状,分别阐述了多单体熔融接枝PP的影响因素、性能及结构,以及多单体熔融接枝PP在尼龙中的应用;并指出了其存在的问题及发展前景.     

高极性聚丙烯的制备及应用

利用双组分熔融接枝极性单体技术,制备高极性聚丙烯（ＰＰ）材料。红外光谱和熔体流动指数测试表明,采用双组分熔融接枝体系,通过加入苯乙烯单体,能够有效地控制单体分员接枝ＰＰ体系中严重的ＰＰ降解,大幅度提高极性单体的接枝率,同时保持了ＰＰ优良的力学性能,从而获得一种力学性能优良的高极性ＰＰ材料。     

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     

新型聚丙烯接枝物的制备及应用

为制备强韧的共混材料,利用熔融接枝法研制了含有两种接技单体的新型聚丙烯接枝物,讨论了第二单体在接枝过程中的作用,并将其应用于尼龙6/聚丙烯(PA6/PP)共混体系,获得了使分散相粒径更细小、界面更模糊的增容效果。     

Supercritical CO2 assisted ternary-monomer grafting copolymerization of polypropylene

Free-radical grafting of ternary-monomer onto polypropylene (PP) particles in the solid state has been studied using supercritical carbon dioxide (SC CO₂) as a solvent and a swelling agent. The PP particles were first swelled with the monomers and AIBN as an initiator, using SC CO₂ at different experimental conditions of pressure, temperature and treatment time. After releasing CO₂, monomers were grafted onto PP in different temperatures. During monomer selection, combination of soft monomer and hard monomer was used in order to tune polarity and flexibility of grafted polymer. FTIR spectra confirmed that ternary-monomer had been grafted onto PP and SEM showed that grafted molecules had been uniformly distributed in the PP substrate. TG analysis indicated that thermal stability of grafting modified PP had been improved, and DSC revealed that grafting leads to a lower degree of crystallinity of polypropylene.     

改性CPP的表征及其对PP附着性能的影响

采用混合单体甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和2-甲基丙烯酸(MAA)对氯化聚丙烯(CPP)进行接枝改性,制备了几种不同接枝率的改性CPP,并用红外光谱和热分析仪对其进行了表征,探讨了改性CPP在PP基材上的附着性能。结果表明:改性CPP在PP塑料上具有良好的附着力;随着接枝率的提高,改性CPP与丙烯酸树脂的相容性增强,其混合液在PP塑料上的附着力达到100%,可用来制备直接涂覆的PP涂料。     

PP-g-MAH对PP/PA6共混物的增容作用

采用熔融接枝法,考察了单体和引发剂用量对聚丙烯(PP)/马来酸酐(MAH)接枝物接枝率的影响。将PP-g-MAH作为PP/尼龙6(PA6)共混物的增容剂,并利用SEM、XRD、DSC-TGA和万能试验机等测试手段对PP-g-MAH增容改性PP/PA6共混体系进行了研究。结果表明,PP-g-MAH接枝物对PP/PA6共混物具有良好的增容效果,PP结晶得到细化,共混物的力学性能和耐高温性能得到改善。     

聚丙烯的接枝改性及其进展

介绍了聚丙烯（PP）接枝改性的几种常用方法，研究进展和接枝PP在增韧增强PP中的应用，并报道了PP／接枝PP／粘土插层纳米复合材料。     

Rheology and morphology of polypropylene in situ grafted and blended with methyl methacrylate/n‐buthylacrylate copolymer

The rheology and morphology of polypropylene (PP) modified by grafting and blending with vinyl monomers were studied in this work. The PP powder was impregnated by mixture of methyl methacrylate (MMA)/n‐buthylacrylate (n‐BA) and copolymerized with azobisisobutyronitrile (AIBN) initiator. The simultaneous grafting and blending of PP with MMA‐co‐n‐BA copolymers were performed in a corotating, 40 L/D, twin‐screw extruder in the presence of dicumyl peroxide. The Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to verify the grafting level and dispersion state of MMA/n‐BA copolymer on PP matrix, respectively, and their rheological properties were studied. It is observed that MMA/n‐BA copolymer is finely dispersed in the PP matrix. In this way, PP can be grafted, blended, and simultaneously compatibilized with polar copolymers, as is seen in SEM images. The results showed that by increasing acrylate monomers grafting on to PP increased. The same trend was observed for AIBN initiator. The gel content of samples with 25% monomers showed an increased from 0.7% to 3.5% by increasing AIBN from 0.2% to 0.4%. The grafting reaction took place with chain scission of PP molecules and also cross‐linking reactions. The optimum grafting of 7.3% with lowest chain scission and cross‐linking were obtained for samples containing 15 wt% monomer and 0.3% AIBN initiator. J. VINYL ADDIT. TECHNOL., 21:290–298, 2015. © 2014 Society of Plastics Engineers     

Functionalization of LDPE and PP to Produce Grafted Membranes Used in Dialysis Processes. Part II

Abstract

Gamma radiation-induced grafting of N-vinyl pyrrolidone (NVP) monomers onto low-density polyethylene (LDPE) and polypropylene (PP) films was studied. The effect of monomer concentration, irradiation dose, and inhibitor concentration on the grafting percent was determined. The swelling behavior of the grafted membranes has been investigated, and it was shown that the modification of LDPE and PP films with hydrophilic monomers results in the growth of the water uptake percent. The permeability of high molecular weight materials such as creatinine and urea, through NVP-grafted membranes increased with increase in grafting percent. Thermal properties of the grafted membranes were studied by using thermo gravimetric analysis (TGA). The morphology of grafted membranes was investigated by using X-ray diffraction (XRD) and the scanning electron microscope (SEM). Structures of the grafted membranes were elucidated by spectroscopic analysis as FTIR, and their mechanical properties were also investigated.     

氯化聚丙烯/丙烯酸酯接枝物的合成和性能研究

采用溶液法用混合单体甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）对氯化聚丙烯（CPP）进行接枝改性,制备出不同接枝率的改性CPP,并对接枝产物进行了傅里叶变换红外光谱分析,探讨了改性CPP在PP底材上得附着性能。结果表明：改性CPP在PP板材上具有良好的附着力;随着接枝率的提高,改性CPP与丙烯酸树脂的相容性增强。     

单体接枝PP包覆纳米CaCO3对PP结晶动力学的影响

采用不同单体接枝聚丙烯(PP)包覆纳米CaCO3与PP复合制备PP/纳米CaCO3复合材料,用差示扫描量热法研究了复合材料中PP的等温和非等温结晶动力学。研究结果表明,不同单体接枝PP包覆纳米CaCO3填充PP复合材料中PP的结晶温度取决于单体类型。PP复合材料的结晶速率高低顺序依次为马来酸酐,丙烯酸丁酯,丙烯酸(或苯乙烯),PP。结晶速率快的复合材料具有低的结晶活化能。     

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.