化学降解法生产高熔融指数聚丙烯的质量控制经验

分析、比较以低熔融指数聚丙烯粉料为基础原料生产纺黏无纺布专用聚丙烯树脂的方法,介绍了通过化学降解法生产高熔融指数聚丙烯无纺布专用料的控制难点。     

聚丙烯粉料纺制高强丙纶色丝

研究了聚丙烯粉料在低熔融指数下防制高强丙纶色丝的生产工艺。结果表明，采用低熔融指数的聚丙烯粉料，选择合理的工艺，可制得有色高强丙纶长丝，其产品可获得物理机械性能和良好的上色率。     

聚丙烯熔融指数的影响因素研究

熔融指数也被称之为熔体流动速率,主要反映塑胶类材料在加工过程中表现出来的流动性。聚丙烯属于一种热塑性树脂,在对其加工生产的过程中,有效控制熔融指数,将其控制在允许的范围之内,有助于保障生产加工产品的质量。基于此,围绕聚丙烯熔融指数的影响因素展开探讨,以更好地控制聚丙烯熔融指数,促进聚丙烯生产加工质量提升。     

间歇式生产中聚丙烯熔融指数的优化控制

间歇式聚丙烯生产中，熔融指数受加氢计量、设备泄漏，反应时间、牌号切换等各种因素的影响，难以控制，批与批之间相差很大，对这些因素进行实验，采用优化控制方法，使批与批之间的熔融指数相近。     

DCPMS作为外给电子体生产低熔融指数聚丙烯

二环戊基二甲氧基硅烷(DCPMS)作为外给电子体,在12 m3反应釜中采用间歇式液相本体法聚丙烯生产工艺,通过控制氢气钢瓶压降为0.1 MPa或绝氢及主催化剂用量为53 g生产熔融指数在0.2-0.3 g/10 min之间的低熔指聚丙烯。与甲基环已基二甲氧基硅烷(CMMS)生产低熔指聚丙烯相比,单釜主催化剂用量由78 g降至53g,并在绝氢状况下熔融指数更易控制在0.2-0.3 g/10 min之间。     

用熔体的零切粘度和熔融指数研究聚丙烯的分子量分布

本文采用自制落球粘度计测定了用高效催化剂和化学降解两种方法生产的常用纤维级聚丙烯的零切粘度η_0,并与熔融指数仪测得的熔融指数MI值相结合求得聚丙烯分子量分布指数α值。研究表明,本法测得的η_0与熔体流变仪测得的η_0基本相符。本文还探讨了影响η_0测试的诸因素,在正确操作情况下,测试误差可小于5%。本仪器简单、价廉,在聚丙烯生产厂可推广使用作为指导生产工艺的依据。     

论聚丙烯高熔融指数（MFR）产品的生产工艺

介绍了聚丙烯高熔融指数产品的三种生产工艺及其对应的产品性能，比较了工艺的优缺点，确定了一种最佳的生产方法。     

聚丙烯熔融指数对GMT力学性能的影响

聚丙烯的熔融指数对GMT的浸渍过程及界面形成过程有着重要的影响。本文通过不同熔融指数的聚丙烯进行实验,得出了不同聚丙烯熔融指数对GMT力学性能的影响,熔融指数高的聚丙烯制得的GMT,其拉伸强度、弯曲强度、弯曲模量均较高,但熔融指数过高,其抗冲击性能要差一些。在本文试验中,熔融指数为20的聚丙烯,制作出的GMT冲击强度最高;而熔融指数为27的聚丙烯,制作出的GMT拉伸及弯曲性能均最高。     

高效催化剂在丙烯聚合中的应用

从两种高效催化剂的试用过程摸索出适合生产实际的反应参数，总结了高效催化剂对聚丙烯产品产量、质量的影响。同时对高熔融指数聚丙烯的生产进行了探索。     

小本体聚丙烯专用料生产工艺的优化

探讨了利用小本体聚丙烯装置生产高熔融指数聚丙烯专用料的影响因素，对聚合催化剂、工艺操作条件等进行优化，通过改造和优化，生产出满足市场要求的专用料，取得较好的经济和社会效益。     

聚丙烯质量性能指标的软测量模型研究

根据丙烯聚合物的特点,分析其关键质量性能指标,定性研究影响这些指标的重要因素;利用反应动力学和系统辨识的方法,建立熔融指数模型并进行验证。     

Melt electrospinning of low‐density polyethylene having a low‐melt flow index

Melt electrospinning is a cheaper, more environmentally friendly, and safer alternative to solution electrospinning. We have designed a novel melt spinning device which incorporates a reverse of the normal polarity, with the capillary grounded and the collector grid at positive potential. The apparatus is much simpler and more economical than conventional equipment because no syringe pump is required. Low‐density polyethylene (LDPE) with a low‐melt flow index of 2 g/10 min, which is not suitable for spinning using current commercial methods, was chosen to highlight the advantages of melt electrospinning in general, and our device in particular. The effects of varying the electrospinning parameters such as temperature, electrostatic field, spinning distance, and capillary inner diameter, have been studied. Although it was found that temperatures higher than normal processing temperatures had to be employed in our electrospinning system to reduce the viscosity of the polymer melt sufficiently, good quality fibers with smooth and even surfaces, most of which had diameters smaller than 15 μm, were electrospun successfully. It was observed that there was an optimum point for the spinning distance (14–15 cm) and the capillary inner diameter (0.4–0.6 mm) to get fine fiber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

高熔体指数PP专用料研制

简要介绍了以分子量较高的聚丙烯为基础树脂,采用化学降解一步法制得纤维级聚丙烯树脂的过程。该树脂等规指数高、分子量分布窄、熔体指数在20～80g/10min内可调,是高、中速纺丝及熔喷法、纺粘法无纺布的理想原料。     

In-line fiber-optic near-infrared spectroscopy: Monitoring of rheological properties in an extrusion process. Part I.

In-line monitoring of chemical processes is desired for its numerous advantages, such as lesser waste, lower developmental cycle time, and lesser costs. In this study, a methodology is presented for estimating polymer rheological properties using fiber-optic near-infrared (NIR) spectroscopy. Predictive calibration models are developed for simultaneous, in-line monitoring of polymer melt flow index (MI) and comonomer concentration for a system of poly(ethylene vinyl acetate) copolymers. The NIR spectra of flowing, molten poly(ethylene vinyl acetate) (EVA) copolymers are collected in a flow cell attached to a single-screw extruder. Multivariate statistical regression analysis is presented for correlation of MI and absorbance in the methylene (C—H) stretch, first overtone NIR wavelength region (1620–1840 nm). Results for simultaneous, real-time monitoring of MI and comonomer composition are discussed in detail. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 859–872, 1998     

Influence of molecular weight distribution on flow properties of commercial polyolefins

The aim of this work is to investigate the effects of molecular weight distribution on some conventional flow properties of polyolefins like melt flow index, melt flow ratio, and power law index. The study is designed in two steps. First, the statistical correlation analysis was carried out for proper choice of input variables for each output property and to find the most relevant mathematical forms of the considered parameters for the modeling section. Then the considered property was correlated to the entire molecular weight distribution using spline functions. The best fit was achieved by variation of the number of spline nodes and their values. The proposed methodology is able to be coupled with a polymerization model to correlate the polymerization conditions to the final properties of the product and design a polymerization control loop. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

一次降解法生产高MI聚丙烯

分析了降解法生产工艺过程及存在的生产难点，采取措施解决了问题，实现了高熔体流动指数聚丙烯的大批量生产。     

聚丙烯熔体流动指数测试与分析

在不同负荷和不同温度下,利用熔体流动速率仪测试聚丙烯的熔体流动指数,通过熔体流动指数这种非常简单的方法计算得到剪切应力、剪切速率、非牛顿指数、零切粘黏度和流动活化能等流变参数。     

纺丝直接成布专用聚丙烯切片特性

对纺粘法专用高熔融指数聚丙烯切片71035进行了分子量、分子量分布、流变性和抗静电性能分析,并与国内外同类产品进行了对比。这种新型切片用于纺粘成布比常规切片可降低纺丝温度30℃,物性指标较好。     

熔喷/干法纤网在线复合汽车吸音棉的生产工艺

为了实现熔喷/干法纤网复合汽车吸音棉的在线生产,以开发300 g/m2的复合吸音棉为例,对熔喷工艺、干法纤网工艺以及熔喷/干法纤网在线复合等内容进行了分析介绍。结果表明:采用熔融指数150 g/min的聚丙烯切片,并控制好模头温度、热空气喷射角、热空气压力、接收距离等熔喷工艺参数,采用纤度为3.3 dtex的三维卷曲涤纶中空短纤维和阻燃涤纶短纤维组成的干法纤网,纤网加入熔喷丝的角度在75～83°之间时,能够得到较好的复合吸音棉材料。