亚洲综合在线播放_久久视频免费在线_久久久黄色av_亚洲免费视频一区

pp料應(yīng)用介紹：

聚丙烯塑料的改性可分為化學(xué)改性和物理改性?xún)煞N方法。化學(xué)改性主要通過(guò)共聚、接枝、交聯(lián)等方式, 改變聚丙烯的分子結(jié)構(gòu)以達(dá)到改性的目的; 物理改性則在整個(gè)改性過(guò)程中不發(fā)生化學(xué)反應(yīng), 在PP基體中加入其他無(wú)機(jī)材料、有機(jī)材料、其他塑料、橡膠、熱塑性彈性體或有特殊功能的添加助劑等, 經(jīng)過(guò)共混、增強(qiáng)或填充等手段制得具有優(yōu)異性能的PP復(fù)合材料。

注塑工藝參數(shù)對(duì)pp料塑料熔體表觀黏度的影響：

聚丙烯( PP) 屬于結(jié)晶性高聚物，有著質(zhì)輕、無(wú)毒、價(jià)廉、耐高溫等優(yōu)點(diǎn)，在醫(yī)藥、食品、汽車(chē)和化工等領(lǐng)域中有著廣泛的用途。PP 是典型的熱塑性塑料之一，自從米蘭理工大學(xué)的G． Natta 教授發(fā)現(xiàn)等規(guī)聚丙烯以來(lái)，全球的聚丙烯工業(yè)迅速發(fā)展，現(xiàn)今產(chǎn)量?jī)H次于聚乙烯。注塑成型能夠一次成型外形復(fù)雜、尺寸或帶有嵌件的塑料制品，是塑料加工的主要方法之一。塑料熔體的表觀黏度可以指導(dǎo)擬定注塑工藝，也能夠指導(dǎo)模具型腔設(shè)計(jì)和優(yōu)化流道澆注系統(tǒng)。

長(zhǎng)期現(xiàn)貨pp3015耐高溫

Rheological Properties of Flame Retardent and Antistatic Polypropylene Material

WANG Shuai 1,2, WANG Kejian 1*, MA Yi 2*, ZHANG Yinling 2, LIANG Wenbin 2,WANG Xu 1,SHI Jiao 1,JIANG Zhuoyu 1

（1 College of Mechanical and Electrical Engineering, Beijing University of Chemical and Technology， Beijing 100029，China;2 National Institute of Clean and Low Carbon Energy，Beijing 102211，China）

Abstract: The effects of brominated flame retardant and carbon black-filling on the extrusion distortion of PP melt and dynamic rheological properties were investigated by capillary rheometer and rotational rheometer. It was shown that the more filled resin exhibited higher critical shear rate for extrusion distortion corresponding to wider processing window in low filler content range. In dynamic rheometry, the higher filled resins behavior in shear thinning with higher complex viscosity，storage modulus and loss modulus instead of lower loss factor. Quantitative analyses were conducted using entanglement model and Cross model. Filler can absorb polymer chains reducing wall adsorption dropping distortion and further resulting in higher critical shear rate. Particle filled network increases in the plateau modulus and entanglement density shortening relaxation time for quicker recovering according to smaller extrusion swell ratio. Carbon black more than 3.5wt% in composite forms percolation network being characterized by higher zero shear viscosity and longer relaxation time where liquid-solid-like transition occurs. Simultaneously, the surface resistivity decreased obviously. The viscoelastic percolation value consistent with the electrical percolation value approximately.

Keywords: Rheology; polymer; particle; composites; extrusion distortion; percolation network。

長(zhǎng)期現(xiàn)貨pp3015耐高溫

pp顆粒原料特點(diǎn)：

特點(diǎn)：無(wú)毒、無(wú)味，密度小，強(qiáng)度、剛度、硬度耐熱性均優(yōu)于低壓聚乙烯,可在100度左右使用.具有良好的電性能和高頻絕緣性不受濕度影響,但低溫時(shí)變脆、不耐磨、易老化.適于制作一般機(jī)械零件,耐腐蝕零件和絕緣零件 。常見(jiàn)的酸、堿有機(jī)溶劑對(duì)它幾乎不起作用，可用于食具。

車(chē)用pp顆粒改性介紹：

改性PP 的氣味組成及形成：改性PP 材料的氣味主要來(lái)源于材料的揮發(fā)性有機(jī)化合物(VOC)，其組成可以通過(guò)氣相色譜– 有機(jī)質(zhì)譜聯(lián)用儀、頂空法等方法進(jìn)行分析。羅忠富通過(guò)氣相色譜–質(zhì)譜對(duì)車(chē)用PP 復(fù)合材料氣味進(jìn)行了分析研究。結(jié)果發(fā)現(xiàn)，PP 材料的揮發(fā)性氣體組分有近20 種，主要由羰基化合物與烴類(lèi)化合物組成，并且在這些組分中，羰基化合物如酮、醛與酯比烴類(lèi)化合物能產(chǎn)生更明顯的氣味。