废胶粉/聚丙烯热塑性弹性体的界面增容研究

采取多种相容剂和反应加工手段，设计轮胎胎面废胶粉（WRP）与聚丙烯（PP）体系的不同界面，旨在制备出性能优异的热塑性弹性体（TPE）。研究了纯WRP／纯PP、三元乙丙橡胶（EPDM）包覆WRP／纯PP、丁苯吡橡胶（BSPR）包覆WRP／接枝马来酸酐聚丙烯（MPP）／PP、特殊高分子相容剂（SMC）包覆WRP／纯PP、原位接枝胺基WRP／MPP／PP、动态接枝纯WRP／纯PP等六种体系制备的TPE的性能，WRP／树脂质量比为70／30。结果表明，采用后三种体系制备的TPE性能优良，已经接近天然橡胶／聚丙烯TPE的性能水准，但WRP必须用酚醛树脂进行改性。据此，提出强界面和合适的界面模量过渡是制备废胶粉／树脂热塑性弹性体的关键。TEM的相态研究表明：胶粉的分散粒径在几到十几个微米之间，较原始粒径有很大的细化。     

接枝改性无卤阻燃聚丙烯的研究

采用接枝改性手段把含有极性基团的乙烯基单体引入非极性的PP大分子骨架，将PP功能化，再与非卤阻燃剂如含NH2基的P－N膨胀型阻燃剂等进行大分子反应，制备了非卤阻燃聚丙烯母粒。着重探讨了含极性基团的乙烯基单体种类及用量等因素对PP阻燃性的影响。在PP大分子链上接枝含极性基团的乙烯基单体，可显著提高PP的阻燃性能；在双单体接枝体系中，单体A与C的配比为10／30时，最高氧指数可达32．0。     

PP-R铝塑复合管用热熔胶的研制

将PP／HDPE用马来酸酐(MAH)进行熔融接枝改性制得PP—R铝塑复合管用热熔胶树脂，红外光谱分析证实MAH确已接枝到树脂上。当HDPE比例占40％，MAH接枝率0．7％时，树脂与铝箔和PP—R有最大的剥离强度。在该树脂中添加10％的增粘树脂、40％的粘度调节剂后，获得了剥离强度达135N／cm的热熔胶。     

丙烯酸改性Sb2O3/PP的化学作用与断裂形态

用双螺杆挤出机制备了三氧化二锑／聚丙烯(Sb2O3／PP)和丙烯酸(AA)改性Sb2O3／PP母料，用IR、熔体流动速率仪和SEM研究了Sb2O3／PP母料和改性Sb2O3／PP母料中化学作用、熔体流动速率和断裂形态。结果表明，AA在母料中能与Sb2O3发生强的界面相互作用，与PP发生接枝作用，使母料的熔体流动速率降低，改善粒子与基体的界面粘结，断裂形态改变。     

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。     

PP-HBP改性PP／PVO的流变行为

研究了聚丙烯接枝超支化聚（酰胺酯）（PPHBP）／PP／聚氯乙烯（PVC）共混体系的流变行为。讨论了PP-HBP用煮对PP／PVC共混体系流变行为的影响。结果表明，当PP／PVC共混体系中加入PPHBP不大于5份时，PP／PVC／PPHBP共混体系的表观粘度大于PP／PVc共混体系的；当加入PP—HBP大于5份时，PP／PVC／PP-HBP共混体系的表观粘度小于PP／PVC共混体系的；随着温度升高，PP／PVC和PP／PVC／PP—HBP共混体系表观粘度减小。     

粉状聚丙烯增韧增强研究

采用机械共混方法对粉状聚丙烯（PP）进行了增韧增强研究，探讨了增韧剂、增强剂和有少量自制的固相甲基丙烯酸（MAA）接枝粉状聚丙烯（PP-g-MAA)作增容剂存在下对粉状PP共混体系力学性能的影响，用热重分析法考察了改性粉状PP的热性能。结果表明，（乙烯／丙烯／二烯）共聚物（EPDM）／高密度聚乙烯（HDPE）为复合增韧剂，具有协同作用，可显著提高共混物的冲击强度：PP-g-MAA能明显改善PP／玻纤两相的界面结合力；PP／EPDM／HDPE玻璃纤维共混体系可以获得理想的增韧增强效果。     

反应改性纳米CaCO3／PP复合材料的力学性能研究

利用反应性单体甲基丙烯酸（MA）接枝聚丙烯（PP）后，二步法制备了反应改性纳米CaCO3／PP复合材料。研究了复合材料的力学性能，并用扫描电子显微镜（SEM）观察了复合材料经液氮冷却脆断后断面的形态。结果表明，甲基丙烯酸接枝聚丙烯（MAPP）加入后与CaCO3反应使MAPP与纳米CaCO3微聚体之间产生离子键作用，使纳米／PP复合材料的力学性能得到大幅提升，对冲击性能的改善尤为明显。充分控制的MA反应量比单独依靠MAPP增容能够更为有效地提高纳米CaCO3的分散性和界面黏结性。     

ABS/PP相容剂的制备及应用

利用Brabender挤出机和密炼机分别制备了PP熔融接枝物PP—g—MAH，并用化学滴定法对接枝物的接枝率进行了定量分析，讨论了熔融接枝PP过程中过氧化二异丙苯、马来酸酐的用量对接枝率的影响，对比了2种不同工艺对pp-g-MAH接枝率的影响，实验还研究了相容剂对共混物力学性能影响。结果表明，PP—g—MAH的加入，在一定程度上改善了共混物的冲击性能、加工流动性和耐热性能。     

PP／PPMA／Org—MMT复合材料的制备与性能研究

采用熔融插层法制备PP／PPMA／Org-MMT复合材料，考察接枝物含量、不同聚丙烯、不同接枝率接枝物以及不同成型工艺对PP／PPMA／Org-MMT复合材料的制备与力学性能的影响。结果表明，采用PP（F401）、高接枝率接枝物和模压工艺可获得较好的插层效果。接枝物含量为10％时，PP／PPMA／Org-MMT复合材料的拉伸强度达到最大值。     

PP-g-(MAH-St)对PP/木粉复合材料力学性能的影响

在聚丙烯中(PP)中添加马来酸酐(MAH)和共单体苯乙烯(St),通过熔融挤出法制备了高接枝率的PP-g-(MAH-St),红外光谱分析证明了St和MAH成功接枝到PP主链上。研究了PP-g-(MAH-St)对PP/木粉复合材料力学性能的影响,并用扫描电镜观察了复合材料冲击断面的微观形貌。结果表明,与现有PP-g-MAH相比,只要添加少量PP-g-(MAH-St)就能有效改善PP/木粉复合材料的界面相容性,从而提高材料的力学性能;PP-g-(MAH-St)中MAH的接枝率对复合材料力学性能影响显著,当MAH接枝率为2.8 %时,能使木塑复合材料力学性能达到最佳。     

Radiation‐induced grafting of pentamethyl hindered amine light stabilizer 1,2,2,6,6‐pentamethyl‐4‐piperidinyl methacrylate onto polypropylene

The γ‐radiation‐induced grafting of 1,2,2,6,6‐pentamethyl‐4‐piperidinyl methacrylate (PMPM) onto polypropylene (PP) was investigated with a simultaneous irradiation technique. The effects of the solvent, dose, monomer concentration, and photoinitiator on the grafting were investigated. The grafting was easier in a benzene solution than in chloroform and acetone solutions. The grafting percentage first increased almost linearly with the irradiation dose until 20 kGy and then increased slowly or remained constant. The grafting percentage increased with the monomer concentration until 1.1 mol/L. The grafting percentage was higher when the proper amount of benzophenone was added. The grafted samples were characterized with Fourier transform infrared spectroscopy and thermogravimetric analysis. Carbonyl groups were found on grafted PP samples, and the carbonyl index increased with the grafting percentage. Thermogravimetric analyses proved the existence of grafted materials on PP, and grafted PMPM thermally decomposed at a lower temperature than PP. The radiation resistance of PP with grafted PMPM was better than that of pristine PP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2157–2164, 2005     

PP-g-Si对PP／GF的增容作用

制备了硅烷接枝聚丙烯(PP-g-Si)，研究了PP-g-Si作为聚丙烯／玻纤(PP／GF)复合体系的界面相容剂对界面结合和力学性能的影响，并与马来酸酐接枝聚丙烯(PP-g-MAH)的增容效果进行了比较。结果表明，PP-g-Si对PP／GF体系有增容作用，不仅可以改善PP／GF复合体系的拉伸强度，而且可以改善其韧性。硅烷接枝聚丙烯可以降低PP／GF复合体系的最大扭矩。玻纤的加入可以提高聚丙烯的热变形温度，硅烷接枝聚丙烯对PP／GF复合体系的热变形温度有稍微改善。扫描电镜观察表明，玻纤与基体间具有强有力的界面结合，硅烷接枝聚丙烯的增容效果优于马来酸酐接枝聚丙烯。     

m-异丙烯基-α, α-二甲基苄基异氰酸酯熔融接枝聚丙烯的研究

在苯乙烯(St)存在下,将含不饱和键和异氰酸酯双官能团的单体m-异丙烯基-α, α-二甲基苄基-异氰酸酯(m-TMI)熔融接枝到聚丙烯(PP)上,分别采用无水滴定法、红外光谱、热重分析和差示扫描量热法对接枝产物进行测试。结果表明,m-TMI、St均与PP发生接枝反应,并且St的存在能够有效抑制PP在接枝过程中的降解,提高m-TMI与PP的接枝产物的热稳定性。在保持St用量不变的条件下,m-TMI的接枝率和接枝效率随其用量的增加先增大后减小;在保持m-TMI用量不变的条件下,m-TMI的接枝率在St与m-TMI的摩尔比为1.6时达到最大值。     

反应性相容剂的制备及其在PP/玻璃纤维复合材料中的应用

以马来酸酐(MAH)为接枝单体、丙烯酸-2-羟乙酯为共聚单体,利用熔融接枝技术对聚丙烯(PP)进行改性;以MAH/丙烯酸-2-羟乙酯熔融接枝改性PP为相容剂,研究相容剂对PP/玻璃纤维复合材料结构和性能的影响。结果表明:与未接枝PP相比,熔融接枝PP分子上接枝了MAH和—OH基团,而且熔融接枝反应对PP的熔点和热稳定性具有明显影响。另外,随着接枝PP含量的增加,PP/玻璃纤维复合材料的力学性能明显改善。当接枝PP含量为15%时,复合材料的拉伸强度提高了32%,冲击强度提高了13%,表明采用熔融共接枝工艺制备的PP具有优良的增容、偶联和分散效果。     

Influence of grafting formulations and extrusion conditions on properties of silane‐grafted polypropylenes

The melt grafting of unsaturated silanes onto powdered polypropylene (PP) in a Haake TW100 twin‐screw extruder and curing in hot water were studied. The influence of grafting formulations and extrusion conditions on the melt flow rates of grafted PP and the gel percentages of crosslinked PP was investigated. The gel percentages of methacryloylpropyltrimethoxysilane (VMMS)‐grafted PP were markedly higher than those of vinyltriethoxysilane (VTES)‐ and vinyltrimethoxysilane (VTMS)‐grafted PP, while significantly less degradation of PP during grafting was observed for VMMS‐grafted PP. When benzoyl peroxide (BPO) was used as an initiator, no degradation of PP during grafting was observed, and the melt flow rates of grafted PP decreased with increasing BPO concentration. In contrast, use of dicumyl peroxide (DCP) as an initiator resulted in severe degradation of PP, and the melt flow rates of grafted PP increased gradually with increasing DCP concentration. BPO resulted in higher gel percentages than those of DCP at a fixed initiator concentration. Introduction of styrene into the grafting system greatly improved the gel percentage of crosslinked PP and reduced the degradation of PP during grafting. The optimum molar ratio of styrene to monomer is at about 1.5:1. Relatively low processing temperatures and high screw speeds are favorable. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1233–1238, 2000     

PP-g-GMA的制备及其改性PP/PA6合金性能

采用双螺杆熔融接枝的方法,在引发剂过氧化二异丙苯(DCP)作用下,将甲基丙烯酸缩水甘油酯(GMA)和共单体苯乙烯(St)接枝到聚丙烯(PP)上。通过傅立叶变换红外光谱仪确定了接枝物的生成,采用酸碱滴定法测定了接枝率。探讨了GMA,St,DCP不同用量对PP接枝物的接枝率和熔体流动速率的影响,并将接枝产物PP–g–(St–co–GMA)加入PP/尼龙6(PA6)的合金中,通过注塑成型样条,测定其力学性能,并观察微观结构。结果表明,St的加入能够提高接枝率,抑制副反应的发生。在PP/PA6合金中加入接枝物PP–g–(St–co–GMA),其拉伸强度可提高46.45%,弯曲强度可提高32.47%,但对冲击强度影响不大。     

马来酸接枝PP增容PA6/PP合金的研究

研究了马来酸接枝聚丙烯(MAC-g-PP)的熔体流动速率(MFR)、接枝率与接枝配方的关系,PA6/接枝PP/PP合金的力学性能与接枝PP的特征参数、用量,以及PA6/(PP 接枝PP)配比的关系。结果表明,合金的力学性能随接枝PP的MFR增加而提高,与接枝率无关,接枝PP用量有一最佳值,高MFR的MAC-g-PP能显著改善合金的冲击韧性。     

A reactive extrusion process for the free radical grafting of silanes onto polypropylene: Effects of processing conditions and properties of water cross‐linked silane‐grafted polypropylene

Silane grafting and water cross‐linking of polypropylene (PP) are a recent method to modify its properties, such as melt strength, heat, and chemical resistance. This work aims at grafting silanes onto PP by reactive extrusion. The occurrence of the grafting of silane onto PP was confirmed by Fourier transform infrared (FTIR) and a method based on FTIR was developed to quantify the amount of polymerized silane and that of silane grafted onto PP. The molar mass of the silane‐grafted PP and its melt viscosity were also measured. A multiobjective optimization strategy was used to study the effects of processing conditions on the quality of the silane‐modified PP. It was concluded that to maximize the amount of silane grafted on PP and minimize the amount of polymerized silane and the decrease in PP chain scission, screw speed and barrel temperature should be low and feed rate high. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

Melt grafting of a long-chain unsaturated carboxylic acid onto polypropylene

The melt grafting of a long-chain unsaturated carboxylic acid such as oleic acid (OA) and undecylenic acid (UA) onto polypropylene (PP) in a Haake Rheocord RC90 mixer was studied. The influence of initiator concentration, monomer concentration and reaction temperature on grafting was investigated. The experimental results show that a higher degree of grafting was obtained using mixed initiators (DCP/BPO=1:1). Increasing the monomer concentration leads to an initial rapid increase in the degree of grafting. The addition of styrene reduced the degradation of PP as well as the degree of grafting. The monomer chain length influenced grafting significantly, the degree of grafting decreasing with increasing chain length of the grafting monomer. The results of differential scanning calorimetry (DSC) indicated that the crystalline properties of PP grafted with OA and UA were different from those of PP grafted with acrylic acid (AA), which may be attributed to the nucleation effect of the grafted long chain of OA and UA.