PP/POE/CaCO3复合材料的性能研究

采用熔融共混工艺制备了聚丙烯/聚烯烃弹性体/碳酸钙(PP/POE/CaCO3)复合材料,研究了POE及CaCO3用量对复合材料力学性能、流变性能及热性能的影响。结果表明:随着POE含量的增加,复合材料的冲击强度显著增大,当POE含量为12%时,冲击强度较纯PP增加233%;同时拉伸强度随POE含量的增加缓慢下降。随着CaCO3含量增加,冲击强度先增加后缓慢下降。     

低频振动注塑改善PP/纳米CaCO3分散性的研究

利用自行研制的振动注塑装置研究了低频振动对PP／纳米CaCO3体系中纳米CaCO3在基体中的分散性。结果表明,在低频高压下,无机粒子在基体中的分散性有了明显的改善,使体系拉伸强度和冲击强度同时得到了提高。     

全程振动注塑对PP力学性能影响研究

以实际生产条件为前提，在频率为0～12Hz、振幅为0～0．28mm范围内研究了振动对聚丙烯（PP）力学性能和冲击断面形态结构的影响。结果表明，PP的力学性能对振动参数的响应并不完全是一个单调趋势，而是存在一个最佳的响应范围；全程振动注塑能够同时提高PP的拉伸强度和冲击强度，最大增幅分别为17％和27％。     

纳米CaCO3增韧增强PP研究

研究了纳米及微米CaCO,对聚丙烯(PP)力学性能的影响,探讨了纳米CaCO,增韧增强PP的机理,并用扫描电子显微镜及差示扫描量热仪对改性PP进行观察与分析。结果表明,纳米CaCO,改性PP的力学性能优于微米CaCO3改性PP;纳米CaCO3用量为10—12份时,改性PP综合性能较好;纳米CaCO3改性PP力学性能的提高可用“开关模型”解释并与卢晶的形成有关。     

纳米CaCO3/PP复合材料的制备与性能研究

分别采用钛酸酯偶联剂、硅烷偶联剂、铝酸酯偶联剂等对纳米CaCO3进行表面处理,通过熔融共混法制备了纳米CaCO3/PP复合材料,并进行了力学性能测试与表征.结果表明,经过三种偶联剂处理后的纳米CaCO3能显著提高PP的缺口冲击韧性,其中NDZ-201钛酸酯偶联剂的处理效果最佳,当纳米CaCO3质量分数为7%时,对PP的改性效果最好,缺口冲击韧性提高了38%,弯曲模量提高了33%.     

全程振动注塑对PP力学性能影响的研究

以实际生产条件为前提,在频率0～12Hz、振幅0～0．28mm范围内研究了振动对聚丙烯(PP)力学性能和冲击断面形态结构的影响。结果表明,PP的力学性能对振动参数的响应并不完全是一个单调趋势,而是存在一个最佳的响应范围;全程振动注塑能够同时提高PP的拉伸强度和冲击强度,最大增幅分别为17％和27％。     

改性纳米CaCO3/PP动态力学性能的研究

熔融制备了反应性单体改性纳米CaCO3/PP复合材料,用DMA研究了反应性单体对纳米CaCO3/PP复合材料动态力学性能的影响.结果表明纳米CaCO3的加入提高了PP的储存模量E′和损耗模量E″,降低了E″的峰温和β转变温度.丙烯酸AA改性有降低复合材料的E′和E″的作用,但不明显影响转变温度.苯乙烯St或与AA混合改性明显提高复合材料的E′和E″,也明显地降低E″的峰温.不管是否对反应性单体改性,纳米CaCO3加入均使PP的β转变温度移向低温.     

PP／CaCO3复合材料的力学性能研究

通过采用熔融共混的方法制备了PP／CaCO3复合材料，然后对复合材料的力学性能进行分析，研究了微米级和纳米级CaCO3的表面处理、含量对PP／CaCO3复合材料力学性能的影响规律，并对此影响规律进行合理的解释。     

PP/CaCO3低发泡片材的开发研究

聚丙烯与其他聚烯烃共混改性，可明显提高熔体强度，采用40％CaCO3填充聚丙烯后用RA发泡剂发泡，可制得PP／Ca－CO3低发泡片材（密度为0．904g/cm^3）。该片材具有良好的可降解性，用于替代聚苯乙烯（PS）或纸浆制备一次性餐具，其力学性能可满足使用要求。     

PP/POE/纳米CaCO3复合材料的改性

对三元复合体系聚丙烯(PP)／聚烯烃弹性体(POE)／纳米CaCO3进行了改性研究，主要探讨了马来酸酐接枝聚丙烯(PP-g-MAH)、乙烯一醋酸乙烯共聚物(EVA)、均聚聚丙烯(PPH)等聚合物对该复合体系性能的影响。研究结果表明，加入适量的接枝物有利于三元复合材料强度的提高，在特定的配比下，PPH和PP3(共聚丙烯)可分别作为该复合体系的熔体流动速率调节剂和增韧剂。     

振动注射成型对等规聚丙烯的结构和静态力学松弛行为的影响

采用自行研制的机械振动注塑装置,在不同振动频率和振动压力下制得等规聚丙烯(IPP)振动注塑试样。结合试样的广角X射线衍射(WAXD)、差示扫描量热(DSC)测试结果发现,与常规注塑试样相比,振动应力场促进了PP的结晶,振动试样的结晶度明显提高,晶粒明显细化。在0～15MPa范围内增加振动压力能明显减小试样的蠕变和应力松弛;在0～2.3Hz范围内随着振动频率的增加,试样的蠕变和应力松弛先减小后增大,在振动频率为1Hz时其静态力学松弛性能达到最佳。     

浇口因素对动态注射成型制品影响的研究

对动态注射条件下不同浇口聚丙烯(PP)/碳酸钙(CaCO3)试样的力学性能进行研究.结果表明,在其它工艺参数一定的情况下,大浇口下动态注射成型试样的力学性能比小浇口有一定提高;相对于稳态注射成型,动态注射时浇口越小,试样的力学性能增加幅度越小;振动力场对于CaCO3在PP基体中的分散有很大作用,但浇口大小对最终制品中CaCO3的分布并无明显规律;动态注射成型时试样的熔点随浇口尺寸增大而提高.     

PVC/超细重质CaCO3复合材料的研究及其在注塑件中的应用

研究了2μm超细重质CaCO3改性聚氯乙烯(PVC)树脂的力学性能,并与普通重质CaCO3作了对比。结果表明,两种粒子在PVC注塑件配方中添加份数相同时,添加超细重质CaCO3的PVC材料的力学性能明显优于添加普通重质CaCO3的材料的力学性能;通过扫描电镜照片观察到2μm超细重质CaCO3在PVC基体树脂中分散均匀,PVC/超细重质CaCO3在阀门注塑件上使用效果良好。     

纳米CaCO3／POE／PP三元复合材料成型收缩率的预测

在固定成型工艺条件下，改变纳米CaCO3的添加量，实验采集了该材料的收缩率样本，基于GM（1，1）建立制品收缩率随纳米CaCO3用量变化的预测模型，与实际结果比较，误差在允许的工程误差范围内，证实了该模型的可行性。     

PP/POE/Nano-CaCO3复合材料的动态力学热分析

采用熔融共混工艺制备了聚丙烯(PP)／聚烯烃热塑性弹性体(POE)／纳米CaCO3复合材料。用动态力学试验方法研究了PP／Nano-CaCO3、PP／POE和PE／POE／Nano-CaCO3复合材料的动态力学特征。结果显示：PP／Nano-Ca-CO3PP／POE二元体系的低温内耗峰强度均比PP大;PP／POE／Nano-CaCO3三元复合体系的低温内耗峰强度较之二元体系明显增强,在PE／POE／Nano-CaCO3复合体系中,POE及Nano-CaCO3共同作用使体系tgδ1转变峰逐渐消失,tgδ2峰变宽、增强。利用扫描电子显微镜观察了不同体系的形态,三元复合体系由纯PP的耗能少的空洞化断裂方式逐步向耗能多的基体层屈服方式变化;质量比为100／10／10的PE／POE／Nano-CaCO3复合材料的低温内耗峰强度最大,冲击强度较纯PP提高了178％。     

Improved mechanical properties and structure of PP/nano‐CaCO3 blends prepared by low‐frequency vibration injection molding

BACKGROUD: Melt vibration technology was used to prepare injection samples of polypropylene (PP)/nano‐CaCO₃ blends. It is well known that nano‐CaCO₃ particles are easy to agglomerate owing to their large surface energy. Improving the distribution of nano‐CaCO₃ particles in PP/nano‐CaCO₃ blends is very important for enhancing the mechanical properties. In this work, low‐frequency vibration was imposed on the process of injection molding of PP/nano‐CaCO₃ blends. The aim of importing a vibration field was to change the crystal structure of PP as we studied previously and improve the distribution of nano‐CaCO₃ particles. Furthermore, the mechanical properties were improved. RESULTS: Through melt vibration, the mechanical properties of PP/nano‐CaCO₃ samples were improved significantly. Compared with conventional injection molding, the enhancement of the tensile strength and impact strength of the samples molded by vibration injection molding was 17.68 and 175.96%, respectively. According to scanning electron microscopy, wide‐angle X‐ray diffraction and differential scanning calorimetry measurements, it was found that a much better dispersion of nano‐CaCO₃ in samples was achieved by vibration injection molding. Moreover, the crystal structure of PP in PP/CaCO₃ vibration samples changed. The γ crystal form was achieved at the shear layer of vibration samples. Moreover, the degree of crystallinity of PP in vibration samples increased 6% compared with conventional samples. CONCLUSION: Concerning the microstructure, melt vibration could effectively change the crystal structure and increase the degree of crystallinity of PP besides improving the distribution of nano‐CaCO₃ particles. Concerning the macrostructure, melt vibration could enhance the mechanical properties. The improvement of mechanical properties of PP/nano‐CaCO₃ blends prepared by low‐frequency vibration injection molding should be attributed to the even distribution of nano‐CaCO₃ particles and the formation of γ‐PP and the increase of the degree of cystallinity. Copyright © 2007 Society of Chemical Industry     

Analysis of tensile modulus of PP/nanoclay/CaCO3 ternary nanocomposite using composite theories

The tensile modulus of PP/nanoclay/CaCO₃ hybrid ternary nanocomposite was analyzed using composite models. Rule of mixtures, inverse rule of mixtures, modified rule of mixtures (MROM), Guth, Paul, Counto, Hirsch, Halpin–Tsai, Takayanagi, and Kerner–Nielsen models were developed for three‐phase system containing two nanofillers. Among the studied models, inverse rule of mixtures, Hirsch, Halpin–Tsai, and Kerner–Nielsen models calculated the tensile modulus of PP/nanoclay/CaCO₃ ternary nanocomposite successfully compared with others. Furthermore, the Kerner–Nielsen model was simplified to predict the tensile modulus by volume fractions of nanofillers. Also, Takayanagi model was modified for the current ternary system. The developed Takayanagi model can predict the tensile modulus using Young's modulus and volume fractions of matrix and nanofillers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012