灰色理论在塑料老化行为预测中的应用研究

根据灰色理论构建GM(1,1)预测模型,以湿热条件下聚丙烯和蒙脱土/聚丙烯纳米复合材料的拉伸强度变化的预测为例,研究所建预测模型在塑料老化行为预测中的适用性。聚丙烯和蒙脱土/聚丙烯纳米复合材料拉伸强度的预测结果表明,所建模型的预测精度等级为1级,模拟值与实际值的相对误差最大为4.25%,可用于塑料老化行为的预测。灰色GM(1,1)模型所需实验数据少,预测精度高,为塑料老化行为的预测提供了一种简易而可靠的新途径。     

聚丙烯实用化技术进展

2001年中国聚丙烯消费量为530.3万吨,位居世界第二。但是无论是聚合改性还是共混改性中国和国际先进水平还有不小的差距。本文介绍了近年来聚丙稀的实用化技术进展,包括聚丙烯/无机纳米粘土复合材料、聚丙烯微发泡塑料、成核剂改性聚丙烯材料及长玻纤增强聚丙烯复合材料等领域的技术进展和产品应用概况。     

聚丙烯实用化技术进展

2001年中国聚丙烯消费量为530.3万吨,位居世界第二.但是无论是聚合改性还是共混改性中国和国际先进水平还有不小的差距.本文介绍了近年来聚丙稀的实用化技术进展,包括聚丙烯/无机纳米粘土复合材料、聚丙烯微发泡塑料、成核剂改性聚丙烯材料及长玻纤增强聚丙烯复合材料等领域的技术进展和产品应用概况.     

纳米碳酸钙及其在塑料高性能化改性中的应用

介绍了不同晶形的纳米碳酸钙的特性、制备方法及其表面处理技术，简述了各种纳米碳酸钙改性塑料的制备方法，对纳米碳酸钙在聚氯乙烯、聚乙烯、聚丙烯等塑料的高性能化改性中的应用进行了综述，本文还指出纳米碳酸钙应用于塑料改性中存在的问题。     

聚丙烯实用化技术进展

介绍了近年来聚丙烯的实用化技术进展，包括聚丙烯／无机纳米粘土复合材料、聚丙烯微发泡塑料、成核剂改性聚丙烯材料及长玻纤增强聚丙烯复合材料等的技术进展和产品应用概况。     

聚丙烯实用化技术进展

2001年中国聚丙烯消费量为530．3万吨，位居世界第二。但是无论是聚合改性还是共混改性中国和国际先进水平还有不小的差距。本文介绍了近年来聚丙稀的实用化技术进展，包括聚丙烯/无机纳米粘土复合材料、聚丙烯微发泡塑料、成核剂改性聚丙烯材料及长玻纤增强聚丙烯复合材料等领域的技术进展和产品应用概况。     

抗刮伤型聚丙烯 苯乙烯塑料合金

德国南方化学(Sud-Chemie)与Putsch塑料制品有限公司合作,使用一种改性纳米添加剂成功生产出了抗刮伤级的聚丙烯/苯乙烯塑料合金。这种PP/PS合金将主要应用于汽车内构件的模注部件     

纳米SiO2粒子与聚烯烃弹性体协同改性聚丙烯的研究

采用熔融共混法制备了聚丙烯/纳米二氧化硅及聚丙烯/纳米二氧化硅/聚烯烃弹性体两种体系的纳米复合材料,研究了纳米二氧化硅对聚丙烯/纳米二氧化硅及聚丙烯/纳米二氧化硅/聚烯烃弹性体两种复合体系的力学性能、结晶特性和结晶结构的影响及其特征.结果表明,在纳米二氧化硅与聚烯烃弹性体的协同作用下,聚丙烯的结晶速率加快,结晶温度升高,球晶均匀、细化,材料的韧性和强度得到了较大幅度的提高.     

新品开发

我国研制成功纳米聚丙烯复合材料我国科研人员日前成功地把纳米材料与聚丙烯嫁接在一起,研制出了纳米聚丙烯复合材料。这种以注塑级塑料为基础原料的纳米聚丙烯产品,保持了原有刚性,而使其韧性大幅度提高,是国内首创。据科研人员介绍,不同种类的纳米材料几乎可以与所有牌号的聚丙烯嫁接,制成具有各种优良性能的纳米复合材料,从而大大提高聚丙烯的品质,拓宽聚丙烯产品的应用领域。纳米材料及其技术是最近10年随着科技的发展而形成的新兴应用技术,纳米粒子只有1至100个纳米大小,它本身具有的量子效应、体积效应等使其具有不同于常规材料的光、…     

抗菌聚丙烯实现工业化生产

扬子石化与北京化工研究院共同研发出抗茵聚丙烯YPJ-630KJ新产品，并实现了工业化生产，达到了国家标准要求。这一新产品是在塑料聚合过程加入纳米化抗茵助剂，直接生产抗茵聚丙烯专用料。这一新品的开发，提升了抗茵塑料的使用效率，稳定了质量，进一步适应了市场的需要。     

Nonisothermal Crystallization and Melting Behaviors of PP/PA6/TiO2 Nanocomposites

Titanium dioxide nanoparticles were functionalized with toluene-2,4-diisocyanate and then polypropylene/polyamide 6 blends containing functionalized titanium dioxide were prepared using a twin-screw extruder. The nonisothermal crystallization and melting behaviors of the as-prepared nanocomposites were investigated using differential scanning calorimetry. The nonisothermal crystallization differential scanning calorimetry data were analyzed by the modified-Avrami (Jeziorny) and combination of Ozawa and Avrami (Mo) methods. It can be found that the Jeziorny method can be used to describe the main crystallization process, and the Mo method can better deal with nonisothermal crystallization kinetics of the polypropylene and polyamide 6 phase in polypropylene/polyamide 6-based nanocomposites. The nonisothermal crystallization analysis shows that the titanium dioxide nanoparticles have two effects on polypropylene/polyamide 6 blends, i.e., it can favor the improvement of crystallization ability and decrease the crystallization rate of the polypropylene and polyamide 6 phase in polypropylene/polyamide 6-based nanocomposites. For one thing, the functionalized titanium dioxide nanoparticles in the polypropylene/polyamide 6-based nanocomposites act as effective nucleation agents and result in higher crystallization temperature (T₀) than that of the polypropylene and polyamide 6 in pure polypropylene/polyamide 6 blends, which indicated titanium dioxide nanoparticles favor the improvement of crystallization ability of the polypropylene and polyamide 6 phase. For another, the existence of functionalized titanium dioxide nanoparticles hinders the free movement of polymer chains and results in lower crystallinity than that of the polypropylene and polyamide 6 in pure polypropylene/polyamide 6 blends, which indicated titanium dioxide nanoparticles decrease the crystallization rate of the polypropylene and polyamide 6 phase in polypropylene/polyamide 6-based nanocomposites. The nonisothermal crystallization melting behaviors show that there is single or double melting peak, which varies with different cooling rates for the polyamide 6 phase in polypropylene/polyamide 6-based nanocomposites. Multiple melting peak is mainly caused by the different crystalline structure of the polyamide 6 phase, the melting peak I is mainly caused by γ crystal of the polyamide 6 phase, while the melting peak II corresponds to the thermodynamic stability of α crystal. Besides, the recrystallization of the polyamide 6 phase in the heating process, and the effect of the incorporation of the titanium dioxide nanoparticles may have some contributions to the appeared multiple melting peak of the polyamide 6 phase in the polypropylene/polyamide 6-based nanocomposites.     

Nanoindentation Creep,Nano-Impact,and Thermal Properties of Multiwall Carbon Nanotubes–Polypropylene Nanocomposites Prepared via Melt Blending

Morphological analysis of the nanocomposites showed that multi-wall carbon nanotubes were uniformly distributed in polypropylene. Nanoindentation creep and nano-impact tests were carried out. Several equations/models were used to analyze creep data. From creep test, hardness of the nanocomposites increased by 18 and 36% for C150P and C70P, respectively, compared to polypropylene, whereas elasticity also increased by 20 and 34%. From nano-impact test, hardness of the nanocomposites was also higher than that of neat polypropylene. However, hardness (dynamic/impact) values were slightly higher than the (quasi-static) hardness resulted from creep test. In addition, degree of crystallinity of nanocomposites also increased by 12.6 and 14.3%.     

聚丙烯纳米复合材料的研究进展

对聚丙烯纳米复合材料的国内外研究进展进行了综述,重点讨论了聚丙烯／层状硅酸盐和聚丙烯／无机刚性粒子这两类纳米复合材料的增强增韧机理、制备方法与性能。     

Evaluation of amine functionalized polypropylenes as compatibilizers for polypropylene nanocomposites

The compatibilization effects provided by amine functionalized polypropylenes versus those of a maleated polypropylene, PP-g-MA, for forming polypropylene-based nanocomposites were compared. Amine functionalized polypropylenes were prepared by reaction of maleated polypropylene, PP-g-MA, with 1,12-diaminododecane in the melt to form PP-g-NH₂ which was subsequently protonated to form PP-g-NH₃⁺. Nanocomposites were prepared by melt processing using a DSM microcompounder (residence time of 10 min) by blending polypropylene and these functionalized materials with sodium montmorillonite, Na-MMT, and with an organoclay. X-ray and transmission electron microscopy plus tensile modulus tests were used to characterize those nanocomposites. Composites based on Na-MMT as the filler showed almost no improvement of tensile modulus compared to the polymer matrix using any of these functionalized polypropylenes, which indicated that almost no exfoliation was achieved. All the compatibilized nanocomposites using an organoclay, based on quaternary ammonium surfactant modified MMT, as the filler had better clay exfoliation compared to the uncompatibilized PP nanocomposites. Binary and ternary nanocomposites using amine functionalized polypropylenes had good clay exfoliation, but no advantage over those using PP-g-MA. The PP-g-MA/organoclay and PP/PP-g-MA/organoclay nanocomposites showed the most substantial improvements in terms of both mechanical properties and clay exfoliation.     

Morphology,Rheological Properties,and Crystallization Behavior of Polypropylene/Clay Nanocomposites

Polypropylene/clay nanocomposites (PP/I.44P, PPCNs) were prepared in a twin-screw extruder using maleic anhydride grafted polypropylene (MAPP) as a compatibilizer. The intercalation of polypropylene into nanoclay particles was studied using X-ray diffraction. Rheological properties of the nanocomposites were investigated using a rheometer. The enhanced complex viscosity at low frequency regime indicated that the melt elasticity and melt strength of the nanocomposites were improved by adding nanoclay. The non-isothermal crystallization behavior of the nanocomposites was studied using differential scanning calorimetry (DSC) at various cooling rates and was analyzed with the Avrami method. It was found that the nanoclay acted as a heterogeneous nucleating agent resulted in higher crystallization temperature and higher crystallization rate than neat PP. Polarized optical microscopy revealed that the spherulites in the nanocomposites were finer than in the neat system.     

聚合物/层状硅酸盐纳米复合材料的制备研究

本文以聚丙烯和有机蒙脱土为原料，采用插层复合法制备聚合物／层状硅酸盐纳米复合材料，用透射电镜对复合材料的结构进行表征，测定了复合材料的力学性能，结果表明，用马来酸酐化聚丙烯作界面相容剂，聚丙烯大分子链分子插层进入到有机改性蒙脱土的硅酸盐片层中间，并且聚丙烯／蒙脱土纳米复合材料的力学性能有一定的提高。     

Static and dynamic compressive properties of polypropylene/zinc oxide nanocomposites

The effect of strain rate is widely recognized as an essential factor that influences the mechanical properties of polymer matrix composites. Despite its importance, no previous work has been reported on the high‐strain rate behavior of polypropylene/zinc oxide nanocomposites. Based on this, static and dynamic compression properties of polypropylene/zinc oxide nanocomposites, with particle contents of 1%, 3%, and 5% by weight, were successfully studied at different strain rates (i.e., 0.01 s^?1, 0.1 s^?1, 650 s^?1, 900 s^?1, and 1100 s^?1) using a universal testing machine and a split Hopkinson pressure bar apparatus. For standardization, approximately 24 nm of zinc oxide nanoparticles were embedded into polypropylene matrix for each of the tested polypropylene/zinc oxide nanocomposites. Results show that the yield strength, the ultimate strength, and the stiffness properties, of polypropylene/zinc oxide nanocomposites, were greatly affected by both particle loading and applied strain rate. Furthermore, the rate sensitivity and the absorbed energy of all tested specimens showed a positive increment with increasing strain rate, whereas the thermal activation volume showed a contrary trend. In addition, the fractographic analysis and particle dispersion of all composite specimens were successfully obtained using a field emisission scanning electron microscopy. POLYM. ENG. SCI., 54:949–960, 2014. © 2013 Society of Plastics Engineers     

Preparation and characterization of polypropylene/silica nanocomposites by gamma irradiation via ultrafine blend

Polypropylene/silica nanocomposites were prepared by gamma irradiation via ultrafine blend so that the silica at 3% loading level can be well dispersed to polymeric materials for improving their mechanical performance. First, ultrafine blend processing in the melt state is an effective method for improving physical dispersion of nanosilica. Then irradiation technique generates firm and impervious joint between polypropylene and silica, due to the adding of the compatibilizer, maleic anhydride grafted polypropylene. The reaction of maleic anhydride groups with the hydroxyl groups on the surface of nanosilica was characterized by Fourier Transform Infrared Spectra (FTIR). Scanning electronic microscopy (SEM), X-ray diffraction analysis (XRD), differential scanning calorimeter (DSC) and polarized optical microscope (POM) were introduced to characterize the polypropylene/silica nanocomposites. Also the mechanical properties of the nanocomposites were evaluated by tensile strength, young’s modulus and elongation at break, which showed good enhancement due to well dispersed silica and improving interface combination.     

Nanocomposites of isotactic polypropylene reinforced with rod-like cellulose whiskers

Nanocomposite films of isotactic polypropylene reinforced with cellulose whiskers highly dispersed with surfactant were prepared for the first time and compared with either bare or grafted aggregated whiskers. Films obtained by solvent casting from toluene were investigated by means of X-ray diffraction, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. Evaluation of the crystallization behavior showed that the aggregated or surfactant-modified whiskers induced two crystalline forms (α and β) in the nanocomposites and also acted as nucleating agents for isotactic polypropylene. The linear mechanical properties above the glass-rubber transition were found to be drastically enhanced for all three of the nanocomposites as compared to the neat polypropylene matrix, and these effects were attributed to a mechanical coupling between the polypropylene crystallites and filler/filler interactions. For the mechanical experiments at large deformations, the quality of the whisker dispersion was found to play a major role. The nanocomposites obtained with the surfactant-modified whiskers exhibited enhanced ultimate properties when compared to the neat matrix or to the composites containing the other filler types.     

PP/PA6/OMMT复合材料力学性能与结晶性能的研究

采用3种不同有机改性过的蒙脱土(牌号为DK2,DK3,DK5)熔融插层法制备了PP/PA6/OMMT纳米复合物材料,在此基础上使用1%～7%的DK2的蒙脱土再次制备PP/PA6/OMMT纳米复合物材料,借助力学性能测试和差示扫描量热法(DSC)对体系的力学性能和结晶性能进行了研究。结果表明:使用DK2制备的复合材料的力学性能优于使用DK3和DK5制备的复合材料的力学性能;相对于纯PP,PP/PA6/OMMT纳米复合物材料随OMMT含量的增加,拉伸强度和弯曲强度是先增加后降低,最大下降幅度分别为8.7%和5.3%;冲击韧性一直上升达到9.61kJ/m2。OMMT的加入,对PP/PA6有异相成核的作用,提高PP/PA6的结晶速率和结晶度。