透明抗冲共聚聚丙烯的结构与性能对比

采用核磁共振碳谱、红外光谱、凝胶渗透色谱、差示扫描量热法等研究了透明抗冲共聚聚丙烯、普通无规共聚透明聚丙烯、抗冲共聚聚丙烯的结构与性能.结果表明:透明抗冲共聚聚丙烯的乙烯含量介于普通无规共聚透明聚丙烯和抗冲共聚聚丙烯之间,橡胶相含量高于普通无规共聚透明聚丙烯,橡胶相的重均分子量较小,粒径小于0.4μm,分散均一,有利于...     

透明聚丙烯的发展现状及应用

综述了国内外透明聚丙烯的发展现状,以及透明改性剂的研究进展情况;通过对透明聚丙烯与普通聚丙烯以及其它透明材料的性能对比,介绍了透明聚丙烯的优势及应用领域,并提出了发展建议。     

聚丙烯透明改性

叙述了聚丙烯（PP）的透明改性方法和机理,并分析了透明改性剂对PP性能的影响。     

透明聚丙烯成核剂的种类及其应用

介绍了无机类透明成核剂、有机类透明成核剂（芳基磷酸盐、山梨醇类、羧酸金属盐、脱氢枞酸及其盐类、支化酰胺类化合物）和聚合物型透明成核剂的主要品种、特点、在聚丙烯中的成核机理及其对聚丙烯性能的影响。     

透明聚丙烯专用料的结构与性能分析研究进展

近年来我国透明聚丙烯发展迅速，开发透明聚丙烯新牌号替代进口料、满足市场需求是当前急需解决的问题。调控聚丙烯的聚合原理、共聚单元种类及其含量、成核剂的使用以及共混等方法可以在一定程度上提高聚丙烯的光学性能。因此，研究透明聚丙烯微观结构，有助于深入理解聚丙烯宏观性能，从而建立微观结构与宏观性能之间的关系，对指导产品工艺控制、提升透明聚丙烯性能、开发高性能透明聚丙烯专用料具有重要意义。     

纯水塑料瓶透明用材料的选择

本文通过对聚碳（PC）、聚对苯二甲酸乙二醇酯（PET）、聚苯乙烯（PS）和透明聚丙烯（TPP）四种材料透明度、表面性能、力学性能、加工性能的研究、优化出性能／价格比最合适的材料。采用DSC、粘弹仪等对材料内在性能进行了研究，对纯水瓶的加工提出建议。     

冰箱用透明聚丙烯专用料的研制

以普通聚丙烯为主要原料,通过添加透明剂、增韧剂和其它助剂,研制 出了具有综合性能优良的冰箱用透明聚丙烯专用料。考察了透明剂、增韧剂的种类和加入量对专用料材料的影响。经用户试用,开发的专用料流动性、韧性、透明性优良,满足冰箱透明部件的要求。     

改性透明聚丙烯

主要介绍了聚丙烯透明改性的基本原理、透明剂的合成以及聚丙烯的透明改性方法和工艺过程 ,对聚丙烯透明改性的国内外研究现状进行了评述 ,并以山梨糖醇衍生物透明成核剂为主简述了透明聚丙烯的加工过程、性能和应用     

无规共聚透明聚丙烯的研制

用添加透明剂的方法研制了无规共聚透明聚丙烯,通过与无规共聚聚丙烯、均聚透明聚丙烯等的性能比较发现,无规共聚透明聚丙烯的透明性、光泽度好、物理机械性能改善,且缩短了成型周期。     

九江石化透明PP专用料生产新技术通过鉴定

近日，江西省和九江市聚丙烯有关专家根据新技术及成果的鉴定办法和有关规定，对中国石化股份公司九江石化分公司透明聚丙烯（PP）专用料生产新技术的生产工艺、产品性能、经济效益和产品推广应用前景进行了严格的评审鉴定，九江石化分公司《透明PP专用料生产新技术的研发》项目通过了专家的技术成果鉴定。     

聚丙烯的透明改性

以聚丙烯粉料为研究对象,以商品透明成核剂和硬脂酸钙以及抗氧剂1010等助剂为原料,通过熔融共混法制备了透明聚丙烯。通过光透过率测试、X 射线衍射分析、偏光显微镜观察、力学性能测试等手段对所得聚丙烯进行了分析表征。结果表明,随着成核剂的加入,聚丙烯透明性先增加而后下降,最佳加入量为0.25%;成核剂用量的增加,球晶颗粒尺寸减小;加入成核剂,聚丙烯力学性能也明显提高。     

PP/PP-g-MAH/OMMT纳米复合材料流变性能

采用自制聚丙烯(PP)接枝马来酸酐(PP-g-MAH)作为相容剂,与经有机化改性的蒙脱土(OMMT)通过熔融插层法制备了PP/PP-g-MAH/OMMT纳米复合材料,对其加工和流变性能进行了研究.结果发现,随着OMMT用量增加,PP/OMMT和PP-g-MAH/OMMT纳米复合材料的熔体流动速率(MFR)有下降的趋势;...     

羊毛粉/PP共混纺丝和复合纺丝纤维的研究

采用高压空气粉碎羊毛制得的羊毛粉,与聚丙烯(PP)熔融共混纺丝和皮芯型复合纺丝,分别制得羊毛粉/PP共混纤维和复合纤维。对比分析了羊毛粉/PP共混纤维、复合纤维及纯PP纤维的结构和性能。结果表明:羊毛粉/PP共混纤维的断裂强度、初始模量高于复合纤维及纯PP纤维,其大小顺序依次为共混纤维、纯PP纤维、复合纤维;羊毛粉/PP共混纤维的表面染色深度(K/S值)高于复合纤维及PP纤维,其大小顺序依次为共混纤维、复合纤维、纯PP纤维;羊毛粉/PP共混纤维和复合纤维的回潮率均高于纯PP纤维,其大小顺序依次为复合纤维、共混纤维、纯PP纤维。     

ANN方法分析预测聚丙烯材料的力学性能

利用Ｂ－Ｐ人工神经网络（ＡＪＮＮ）对聚丙烯（ＰＰ）的力学性能进行了分析和预测。首先将ＰＰ材料接纯ＰＰ、共混和增韧及填充和增强ＰＰ等进行分类,并根据这些数据的特点建立Ｂ－Ｐ网络,然后用各类ＰＰ材料的组成和力学性能数据对网络进行学习训练,最后用“未知样品”的数据对网络进行验证。结果表明,所建立的网络能反映ＰＰ的力学性能特性,预测有一定的准确性,但不同类别的材料预测准确性不同。     

聚丙烯/n-SiO2复合材料的制备与性能研究

采用熔融共混法制备了PP/纳米SiO2复合材料,并通过力学性能测试、DSC分析以及材料断面形貌分析等手段,对增强增韧效果进行了研究。结果表明,加入纳米SiO2能提高了PP的结晶速率,使结晶度增大。当纳米SiO2的质量分数为2%时可使PP/nSiO2复合材料的缺口冲击强度提高2倍,拉伸强度稍微下降。     

PP/PB共混材料的力学及流变性能研究

采用哈克双螺杆挤出机制备了聚丙烯/聚丁烯-1(PP/PB)共混材料,考察了PB的熔体流动速率(MFR)和用量对PP流变性能和力学性能的影响。结果表明:PP与PB二者相容性良好,当PB质量分数为30%时,PP/PB200(MFR为200 g/10 min)共混材料的MFR最大为37.90 g/10 min,约是纯PP的4.15倍,PP/PB0.5(MFR为0.5 g/10 min)共混材料的MFR最小为7.59 g/10 min,与纯PB相比降低了16.87%;随着PB MFR的增加,PP/PB共混材料的熔体强度降低;当PB MFR为0.5 g/10 min时,对PP有明显的增强和增韧效果,PP/PB共混材料的拉伸强度为31.11 MPa,冲击强度为48.52 kJ/m^2,与纯PP相比分别提高了28.82%和185.24%。     

Effect of Organomodified Ni-Al Layered Double Hydroxide (OLDH) on the Properties of Polypropylene (PP)/LDH Nanocomposites

This work addresses the effect of organomodified layer double hydroxide (OLDH) on the properties of PP/LDH nanocomposites prepared by melt intercalation method using a single screw extruder with maleic anhydride grafted polypropylene (PP-g-MA) as a compatibilizer. For this, Ni-Al LDH was first prepared by the co-precipitation method at constant pH using their nitrate salts. The above synthesized pristine LDH was organically modified using sodium dodecyl sulphate (SDS) by the regeneration method. The structural and thermal properties of LDH and PP nanocomposites were performed by X-ray diffraction (XRD), FTIR spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The influence of LDH loading on the mechanical and thermal properties of the nanocomposite was also investigated. The XRD results confirmed the formation of exfoliated PP/LDH nanocomposites. PP/LDH nanocomposites exhibited enhanced thermal stability relative to the pure PP. When 10% weight loss was selected as a point of comparison, the decomposition temperature of PP/LDH (5 wt%) nanocomposite was 15.3°C higher than that of pure PP. The DSC result indicated an increase in crystallization and melting temperature of the PP/LDH nanocomposites compared to pure PP. Overall, the mechanical properties of the PP/LDH nanocomposites increased with an increase in the LDH content. The maximum improvement of tensile strength, Young's modulus, flexural strength, and flexural modulus for the PP/LDH nanocomposite was found to be 11, 22.5, 28, and 22%, respectively, over neat PP. For comparison purposes, a nanocomposite with 5 wt% modified bentonite (PP/B5) was also prepared under the same operating condition and there was no significant improvement in mechanical properties (tensile strength and modulus).     

Injection Molded Strong Polypropylene Composite Foam Reinforced with Rubber and Talc

Lightweight plastic foams are of great significance for saving resources and reducing energy consumption. Foam injection molding (FIM) shows a promising future to provide lightweight and shape‐complex plastic components. However, it is still challenging to produce lightweight and strong polypropylene (PP) foams by FIM due to PP's poor foaming ability. Herein, rubber and talc are employed to improve PP's foaming ability, and hence to enhance PP foam's mechanical properties. Due to the significantly enhanced rheological properties, injection molded PP composite foam exhibits greatly refined and homogenized cellular structure compared with pure PP foam. Thanks to rubber toughening effect and improved cellular morphology, PP/rubber foam shows much higher ductility than pure PP foam. Moreover, talc particles lead to remarkably enhanced rigidity of PP/rubber foams. Thus, lightweight and strong PP/rubber/talc composite foam is achieved with tensile toughness increased by 82.58% and impact strength increased by 106.21%, and they show broad industrial application prospects.     

Extrusion of ultrahigh molecular weight polyethylene under ultrasonic vibration field

The effects of polypropylene (PP) and ultrasonic irradiation on the processing and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) are studied. The results show that PP can effectively improve the fluidity and mechanical properties of UHMWPE. The Izod notched impact strength increases from 92 kJ/m² for pure UHMWPE to 109.2 kJ/m² for the blend of UHMWPE with 10 wt % PP. The Young's modulus increases from 528 MPa for pure UHMWPE to 1128 MPa when 25 wt % PP is contained in the blend, and the yield strength also rises when PP is added. The application of ultrasonic vibrations during extrusion can prominently decrease the die pressure and apparent viscosity of the melt, thus increasing the output of extrudate. An appropriate ultrasonic intensity and irradiation time can further promote the mechanical properties, while an overdose of irradiation destroys them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2628–2632, 2003     

Improving the flame retardancy of polypropylene by nano metal–organic frameworks and bioethanol coproduct

In this work, a novel flame retardant system based on nano zeolitic imidazolate framework‐8 (ZIF‐8) and the distiller's dried grains with solubles (DDGS) without traditional flame retardants has been designed and blended with polypropylene (PP) to prepare the green flame retarded composites. The influences of nano ZIF‐8 and DDGS on mechanical properties and flame retardancy of PP are studied. The results indicate that combination of nano ZIF‐8 and DDGS improves the mechanical properties of PP, and the tensile strength of the composites containing 29 wt% of DDGS and 1 wt% of nano ZIF‐8 reaches 34.0 MPa compared with 24.7 MPa of pure PP. The limiting oxygen index (LOI) of the composites containing 27 wt% DDGS and 3 wt% of nano ZIF‐8 is about 25.0% compared with 17.5% of pure PP. Besides, its horizontal burning velocity also decreases significantly. The char residues after burning of the PP composites are analyzed, and the mechanism is discussed in detail.