本文選題：聚丙烯　切入點(diǎn)：共混　出處：《華南理工大學(xué)》2011年碩士論文

【摘要】：開(kāi)孔性發(fā)泡塑料是指塑料泡體中的泡孔不是封閉的,氣泡間相互連通的一種泡沫塑料。獨(dú)特的開(kāi)孔結(jié)構(gòu)能夠使微粒和流體在泡沫內(nèi)流動(dòng),通過(guò)精確控制開(kāi)孔泡沫塑料的結(jié)構(gòu)和泡孔的大小,就可以使通過(guò)材料粒子的大小得到控制,使不同粒徑材料分離,實(shí)現(xiàn)特殊過(guò)濾用途。針對(duì)開(kāi)孔性泡沫材料的這種獨(dú)特作用,國(guó)內(nèi)外學(xué)者開(kāi)展了許多制備開(kāi)孔性泡沫材料的研究,提出了一些泡沫塑料開(kāi)孔成型的理論。聚丙烯(PP)具有物理和力學(xué)性能好、原料來(lái)源豐富和價(jià)格便宜等眾多優(yōu)點(diǎn),利用聚丙烯來(lái)制備開(kāi)孔性泡沫材料具有非常重要的現(xiàn)實(shí)意義。 本文以?xún)上喙不旆ㄖ苽溟_(kāi)孔泡沫塑料理論為基礎(chǔ),探索一方面降低易破裂相強(qiáng)度,一方面提高泡孔壁支撐相熔體強(qiáng)度的發(fā)泡方法,以期制備得到開(kāi)孔性良好、泡孔結(jié)構(gòu)規(guī)整的開(kāi)孔泡沫塑料。 本文首先采用PP/LLDPE共混體系進(jìn)行發(fā)泡研究,確定大致工藝條件和配比;然后選用熔體強(qiáng)度較高的高熔體強(qiáng)度聚丙烯HMSPP代替普通PP制備得到共混原料,研究溫度、原料配比等因素對(duì)共混體系發(fā)泡效果的影響;接著選用HMSPP/LLDPE:70/30體系作為考察對(duì)象,研究不同粒徑成核劑、成核劑含量、發(fā)泡溫度、發(fā)泡壓力和剪切速率對(duì)共混體系發(fā)泡樣品泡孔形貌和開(kāi)孔效果的影響;最后,探索了幾種提高共混體系發(fā)泡樣品開(kāi)孔率和完善泡孔結(jié)構(gòu)的新方法。 研究結(jié)果表明:當(dāng)采用PP/LLDPE共混體系作為開(kāi)孔發(fā)泡研究對(duì)象,得到的發(fā)泡樣品泡孔形貌不是很理想,所以采用HMSPP來(lái)代替普通PP進(jìn)行共混發(fā)泡研究。我們發(fā)現(xiàn)HMSPP/LLDPE原料配比和發(fā)泡溫度對(duì)共混體系的開(kāi)孔發(fā)泡影響明顯,當(dāng)原料配比為70:30、發(fā)泡溫度為130℃時(shí)樣品發(fā)泡充分,泡孔形貌較規(guī)整,泡孔尺寸均勻。然后在此配比共混體系中,我們通過(guò)實(shí)驗(yàn)考察發(fā)現(xiàn)成核劑的加入使共混發(fā)泡體系的泡孔孔徑更加均勻。當(dāng)成核劑添加量為3%時(shí),樣品發(fā)泡效果較好,可以觀(guān)察到明顯的開(kāi)孔結(jié)構(gòu)。當(dāng)體系添加5000目成核劑時(shí)的發(fā)泡效果不如添加2500目成核劑時(shí)好。通過(guò)開(kāi)孔率測(cè)算發(fā)現(xiàn),添加成核劑之后樣品的開(kāi)孔率和開(kāi)孔泡孔占全部泡孔體積的比例明顯提高。在開(kāi)孔率改進(jìn)新方法研究中,我們發(fā)現(xiàn)發(fā)現(xiàn)采用粉體LLDPE原料制備的共混體系發(fā)泡樣品開(kāi)孔率較采用粒料LLDPE時(shí)略有提高。而加入石蠟油后,共混體系發(fā)泡樣品的泡孔孔徑減小,泡孔表明變得更光滑,但是其開(kāi)孔率較未加石蠟油的發(fā)泡樣品有所下降。
[Abstract]:Open-cellular foam is a kind of foam in which the pores in the foam are not closed and the bubbles are connected with each other.By accurately controlling the structure and size of the porous plastics, the size of the particles through the material can be controlled and the materials of different particle sizes can be separated.Realize special filtering purpose.In view of this unique role of porous foam materials, many scholars at home and abroad have carried out research on the preparation of porous foam materials, and put forward some theory of porous molding of foam plastics.Polypropylene (PP) has many advantages, such as good physical and mechanical properties, abundant sources of raw materials and low price. It is of great practical significance to use polypropylene to prepare porous foam materials.In this paper, based on the theory of two-phase blending to prepare open-cell foamed plastics, the foaming method of reducing the strength of easily fracturing phase and increasing the melt strength of supporting phase of foaming wall is explored in order to obtain good pore opening property.A structured open-hole foam.In this paper, PP/LLDPE blend system was first used to study the foaming process, and then the high melt strength polypropylene (HMSPP) with high melt strength was used to prepare the blend material instead of ordinary PP, and the temperature was studied.The influence of the ratio of raw materials on the foaming effect of the blend system, and then select the HMSPP/LLDPE:70/30 system as the object of investigation, study the nucleating agent, nucleating agent content and foaming temperature of different particle size, the content of nucleating agent, the foaming temperature, and so on.The effects of foaming pressure and shear rate on the morphology and opening effect of foamed samples were investigated. Finally, several new methods to improve the porosity and improve the structure of foamed samples were explored.The results show that when the PP/LLDPE blend system is used as the research object of open-cell foaming, the foam morphology of the foamed sample is not ideal, so HMSPP is used to study the blending foaming of PP instead of the ordinary PP.It was found that the ratio of HMSPP/LLDPE raw materials and foaming temperature had an obvious effect on the open pore foaming of the blend system. When the ratio of raw materials was 70: 30 and the foaming temperature was 130 鈩，

本文編號(hào)：1709970