悬浮溶胀法合成接枝聚丙烯

用BPO作引发剂以水相悬浮胀法合成接枝聚丙烯，研究了反应条件、组分等因素对PP的接枝率（Gr)和接枝效率（Ge)的影响，发现溶胀剂、悬浮剂、引发剂、催化剂是该接枝物的主要影响因素。用此方法接枝的聚丙烯有工艺简单，接枝率高，聚丙烯降解程度小等优点，用它作PP／CaCO3、PP/PA6、PP／MBS体系的相容剂，测试结果表明，复合材料的力学性能有很大的提高。     

反应挤出PP/LGF复合材料的制备及性能

采用熔融浸渍工艺制备了长玻纤增强聚丙烯复合材料,研究了接枝单体GMA、MA以及引发剂DCP含量对长玻璃纤维增强聚丙烯复合材料力学性能的影响。结果表明:与采用接枝单体GMA相比,采用接枝单体MA反应挤出PP/LGF复合材料的力学性能对引发剂DCP的用量更为敏感,严重影响了PP/LGF复合材料的力学性能;当引发剂DCP质量分数为0.1%,采用接枝单体MA反应挤出PP/LGF复合材料性能最优,并且与没有添加相容剂的PP/LGF复合材料相比,拉伸强度、冲击强度分别提高31%、50%。     

共混工艺对PP/PA6/纳米SiO2复合材料力学性能的影响

以聚丙烯（PP）作为基体，经表面处理过的纳米二氧化硅（nano-SiO2）和刚性聚合物尼龙6（PA6）作为改性剂，添加5％的接枝POE作增容剂，采用不同的共混工艺制备PP／PA6／纳米SiO2复合材料。研究了熔融共混挤出次数和共混方法对PP／PA6／纳米SiO2复合材料力学性能的影响，借助扫描电子显微镜从断面形貌上分析了影响复合材料力学性能的因素。结果表明：采用二次挤出熔融共混比一次挤出熔融共混制得的复合材料力学性能要好；采用PP与纳米SiO2先熔融共混挤出制得粒料，再用PA6、接枝POE与粒料熔融共混挤出的共混方法制得的复合材料综合力学性能最优。     

PP-g-MAH对PP/纳米SiO_2复合材料性能的影响

采用熔融共混法制备了聚丙烯(PP)/纳米SiO2复合材料,研究了相容剂马来酸酐接枝聚丙烯(PP-g-MAH)对复合材料力学性能、结晶性能及界面作用的影响。结果表明:PP-g-MAH能有效地增强纳米SiO2与PP基体间的界面作用,提高复合材料的力学性能;同时,PP-g-MAH增强了纳米SiO2的成核活性,使PP的结晶温度升高,球晶细化。     

高韧性高强度聚丙烯复合材料的研究

研究了自制的马来酸酐接枝聚丙烯(PP-g-MAH)和马来酸酐、苯乙烯接枝聚丙烯(PP-g-MAH-g-St)2种增容剂对聚丙烯/聚烯烃弹性体/玻璃纤维(PP/POE/GF)复合材料力学性能的影响,利用扫描电子显微镜观察了试样断口形貌。结果表明,2种增容剂均显著改善了GF与PP基体的界面粘结强度,从而提高了复合材料的力学性能;就2种增容剂的效果而言,PP-g-MAH-g-St的增容效果远优于PP-g-MAH。当PP-g-MAH-g-St的质量分数为8%时,PP/POE/GF/PP-g-MAH-g-St复合材料的综合性能已接近常用工程塑料的性能。     

长玻纤增强聚丙烯复合材料性能研究

采用熔体浸渍包覆长玻璃纤维装置制备了长玻纤增强聚丙烯(PP/LFT)复合材料,通过双螺杆挤出机制备了同等配比的短玻纤增强聚丙烯(PP/SFT)复合材料。研究了增容剂含量、预浸料颗粒长度以及加工工艺对玻纤增强聚丙烯(PP/GF)复合材料力学性能的影响。结果表明:PP/LFT复合材料的力学性能明显优于PP/SFT复合材料,其拉伸强度及缺口冲击强度分别可达115.0 MPa和42.4 kJ/m~2;增容剂马来酸酐接枝聚丙烯(PP-g-MAH)的加入明显改善了GF与PP间的界面黏结强度,进一步提升了复合材料的力学性能,相比之下,增容剂对PP/SFT复合材料的性能提升效果更为明显;提高预浸料颗粒长度有利于复合材料纤维保留长度和力学性能的提升;适度提高加工温度,可进一步提高浸渍效果和复合材料的力学性能。     

芳纶浆粕增强聚丙烯复合材料的结构与性能

利用双螺杆挤出机制备了聚丙烯(PP) /芳纶浆粕(PPTA-pulp)以及聚丙烯(PP)/芳纶浆粕(PPTA-pulp)/马来酸酐接枝聚丙烯(MAH-g-PP)复合材料。采用力学性能测试、差示扫描量热仪（DSC）、扫描电子显微镜(SEM)、平板流变仪，研究了PP/ PPTA-pulp复合材料的力学性能、结晶行为、断面形态结构及流变行为。结果表明：随着PPTA-pulp含量的增加，复合材料的拉伸强度和弯曲模量增加，缺口冲击强度和断裂伸长率下降，芳纶浆粕对聚丙烯结晶起了成核剂的作用。马来酸酐接枝聚丙烯(MAH-g-PP)作为相容剂，改善了PPTA-pulp与基体PP分子之间的亲和性，提高了界面作用力，并使复合材料的储存模量、损耗模量和力学性能进一步改善。     

纳米氧化硅/弹性体改性PP性能研究

首先研究了不同含量的纳米SiO2对聚丙烯(PP)力学性能的影响,通过综合分析选出最佳配方。还比较了马来酸酐接枝PP(PP-g-MAH)、马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)、马来酸酐接枝PE(PE-g-MAH)对SiO2/PP共混体系力学性能和流动性的影响;最后研究了未接枝POE和POE-g-MAH的配比对SiO2/PP共混体系力学性能的影响。结果表明,SiO2质量分数为8%时混合体系性能较佳;单纯添加接枝POE比添加POE/POE-g-MAH的增韧效果更好,当POE和POE-g-MAH同时使用时,控制一定比例能使二者在增韧上具有协同作用。     

增容方法对聚丙烯/亚麻纤维性能的影响

研究了NaOH溶液浸泡亚麻纤维(FF)、添加马来酸酐接枝聚烯烃(MAH-g-PO)、2种方法相结合对聚丙烯(PP)/FF复合材料力学性能及微观结构的影响.结果表明,NaOH溶液浸泡FF后PP/FF复合材料的力学性能有所提高.相对分子质量较大且接枝率较高的马来酸酐接枝聚丙烯(MAH-g-PP)增容效果较好;马来酸酐接枝三元乙丙橡胶(MAH-g-EPDM)和马来酸酐接枝乙烯辛烯共聚物(MAH-g-POE)对PP/FF复合材料起到增容和增韧的作用.NaOH溶液浸泡FF和添加MAH-g-PO相结合的PP/FF复合材料的力学性能好于单独采用一种方法的PP/FF复合材料的.     

超声波在丙烯酸固相接枝聚丙烯中的应用

利用超声波促进固相接枝反应的原理，研究丙烯酸（AA）接枝聚丙烯（PP）的反应条件：超声波作用时间、接枝反应温度、引发剂过氧化苯甲酰（BPO）及AA用量等对接枝率的影响。研究表明：超声波能有效地促进固相接枝反应的进行。其最佳反应条件是：超声波的作用时间为30min，BPO与AA的用量分别为4％和15％，反应温度为110℃。在上述反应条件下，可以得到接枝率为6％的接枝产物AA接枝PP（PP－g－AA）；并用硅灰石填充含有PP-g-AA的PP复合材料，其力学性能明显优于不含PP－g－AA的硅灰石填充的PP复合材料。     

塑料涂料用马来酸酐接枝氯化聚丙烯的合成与性能

以甲苯为溶剂、过氧化苯甲酰(BPO)为引发剂、马来酸酐(MAH)为接枝单体,对氯化聚丙烯(CPP)进行接枝改性.考察了引发剂和接枝单体用量、反应温度、反应时间以及原料的含氯量对接枝率的影响,并对改性产物进行了傅立叶红外光谱表征.结果表明,氯化聚丙烯成功地接枝上马来酸酐,反应条件和原料的含氯量会影响接枝率,优化的工艺条件为:m(BPO)/m(CPP)=0.04,m(MAH)/m(CPP)=1.1,反应温度为100 ℃,反应时间为3 h.涂料性能测试结果说明,改性产物在部分酮酯类溶剂中的溶解性能优良,对多种塑料材料有良好的附着性能,而附着力的大小受到接枝率的直接影响.     

氯化聚丙烯接枝马来酸酐的研究

为了进一步提高氯化聚丙烯接枝马来酸酐的接枝率,优化工艺条件和不同组分的用量,采用正交实验法,研究了马来酸酐(MAH)用量、引发剂过氧化苯甲酰(BPO)用量、反应温度和反应时间对氯化聚丙烯接枝马来酸酐接枝率的影响。结果表明,引发剂BPO用量对接枝率的影响最为明显,而反应时间相对最弱。4种因素的极差递减顺序为:引发剂BPO用量、MAH用量、反应温度和反应时间。     

Chemical modification‐induced improvement in the electrical characteristics of radiation‐functionalized polypropylene sheets

The development of conducting or semiconducting polymers is a highly interesting area due to the urgent need for new materials that combine several unique properties to be applied in a great variety of electrochemical devices. Polypropylene sheets were functionalized by radiation‐induced grafting of acrylonitrile to import reactive nitrile groups into the inert polymer sheets. To improve the electrical characteristics, such as electrical conductivity, of the radiation‐grafted sheets, a conjugated structure was developed via the repetition of the two‐step condensation polymerization of p‐phenylenediamine and glyoxal using the grafted nitrile groups as starting point. The grafted and treated polypropylene sheets were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). FTIR spectra confirmed the occurrence of the grafting as well as the treatment of the grafted cyanide groups with p‐phenylenediamine and reaction with glyoxal. TGA traces showed an improvement in the thermal stability of the grafted sheets by grafting and a reduction of such stability by chemical treatment. The electrical characteristics of the grafted and treated sheets were evaluated and compared with those of untreated polypropylene. The effects of degree of grafting and conjugated chain length on the electrical characteristics of the grafted sheets were also investigated. The results showed that the development of a conjugated chemical structure in the polypropylene sheets increases the conductivity by about five orders of magnitude. The electrical conductivity of polypropylene was significantly increased as a result of the chemical development of a conjugated double‐bond chain structure in the radiation‐functionalized form. Copyright © 2009 Society of Chemical Industry     

PP-g-MAH制备及其在聚丙烯热熔胶中的应用

利用熔融反应挤出的方法制备聚丙烯接枝马来酸酐(PP-g-MAH),研究了配方组成及加工工艺对接枝聚丙烯性能的影响,通过优化配方和工艺制备了一种高接枝率、低残留率的PP-g-MAH。并通过DSC研究了接枝聚丙烯的熔点和结晶度变化,同时研究了PP-g-MAH对聚丙烯热熔胶黏结性能的影响。结果表明:PP-g-MAH可以显著提高聚丙烯热熔胶的黏结性能。     

马来酸酐固相接枝聚丙烯纤维

了提高非极性聚丙烯纤维(PP)的相容性,采用固相法以马来酸酐(MAH)对聚丙烯纤维进行接枝改性,研究了反应条件对接枝率的影响。结果表明,马来酸酐成功接枝到聚丙烯上,当反应温度为80℃,PP用量为0.5 g,MAH用量为0.2 g,BPO用量为0.05 g,回流时间为2.5 h时,最大接枝率可达到7.51%;BPO的用量、MAH单体的用量以及反应温度对PP纤维的接枝率影响较大。而测定PP纤维接枝率时回流时间对其接枝率的影响不大;接枝聚丙烯纤维的分解温度明显高于纯聚丙烯纤维。     

Surface modification of polypropylene microporous membrane by grafting acrylic acid using physisorbed initiators method

Surface modification of microporous polypropylene (PP) membrane was performed by graft polymerization of acrylic acid using physisorbed initiators method. The factors effecting on the grafting degree such as monomer concentration, reaction temperature and initiator density were determined. The morphological and microstructure changes of the membrane were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). The pure water contact angle, protein adsorbed amount, water flux, and antifouling property of the grafted membrane were investigated. The results indicated that the pore size and porosity of the grafted membrane were reduced and the static contact angle of pure water on the grafted membrane decreased from 108° to 40° with the increase of grafting degree. The amount of protein adsorbed on the grafted membrane decreased about 30% compared to the virgin polypropylene membrane when the grafting degree was 18.71%. Though the water flux reduced, the flux recovery of the grafted membrane increased 82.66% with the grafting degree 16.0%. The hydrophilic and antifouling property of the grafted membrane also were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Experimental study of maleation of polypropylene in various twin‐screw extruder systems

A range of continuous mixing machines were used as continuous reactors for grafting maleic anhydride onto polypropylene. The machines used were (1) a nonintermeshing modular counterrotating twin‐screw extruder, (2) an intermeshing modular corotating twin‐screw extruder, (3) intermeshing modular counterrotating twin‐screw extruder, and (4) a Kobelco Nex‐T continuous mixer. The grafting reaction of maleic anhydride onto polypropylene and degradation of polypropylene during the grafting reaction were investigated as means for comparing these different machines for reactive extrusion. The influence of processing variables such as screw speed and processing temperature on polymer characteristics also was investigated. Generally, in a comparison of the different machines, the intermeshing counterrotating twin‐screw extruder had the lowest levels of grafted maleic anhydride, whereas the Kobelco Nex‐T continuous mixer under the conditions used had the highest levels of grafted maleic anhydride. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1755–1764, 2003     

多单体固相接枝聚丙烯

用乙醚作分散剂,将接枝单体和引发剂均匀分布到聚丙烯(PP)粒子表面,改善相间传质;以偶氮二异丁腈为引发剂,用固相接枝方法制备了丙烯酸丁酯(BA)-马来酸酐(MAH)-苯乙烯(St)接枝PP。考察了接枝单体用量、引发剂用量、反应温度及时间、界面剂用量等对接枝的影响,用傅里叶变换红外光谱仪、热重分析仪和扫描电子显微镜等对接枝产物进行了表征。结果表明:使用分散剂消除了普通固相反应出现的结块现象,接枝单体分布比较均匀;PP为20.0 g时,n(BA)/n(MAH)/n(St)为2:1:1,接枝单体质量分数为6%,引发剂质量分数为0.3%,在80℃反应1.5 h,得到了接枝率为3.48%的接枝产物;产物的拉伸强度没有变化,但极性和热稳定性得到提高。     

超临界二氧化碳协助双单体接枝聚丙烯

采用氧化法制备氢过氧化聚丙烯(HPP),然后用超临界二氧化碳(SC CO2)将单体苯乙烯(St)和季戊四醇三丙烯酸酯(PETA)溶胀到HPP颗粒内,再通过热引发将单体接枝到HPP上.考察了溶胀温度、压力、接枝反应温度、时间及单体用量对产物接枝率与单体接枝效率的影响,并采用红外光谱(FT-IR)、热重-差热分析(TG-DTA)、扫描电子显微镜(SEM)对接枝共聚物进行了表征.结果表明,合适的反应条件为30 g聚丙烯和0.5 g过氧化苯甲酰(BP0)在80℃反应2 h生成HPP,HPP与9 g苯乙烯(St)和季戊四醇三丙烯酸酯(PETA)的混合物(St与PETA物质的量之比为1:1)在37℃,8.5 MPa的超临界CO2中溶胀3 h,再在80℃常压下反应8 h,得到双单体接枝聚丙烯,接枝率达到28%,接枝效率大于90%,且PETA和St同时接枝到了PP分子链上,聚合物的耐热性增强.     

油酸熔融接枝聚丙烯的研究

系统地研究了油酸这一长链不饱和脂肪酸熔融接枝聚丙烯（ＰＰ）,探讨了反应条件（如转速、反应温度、反应时间）、引发剂类型及浓度、单体浓度、加入第２单体（苯乙烯）等因素对接枝反应的影响。采用红外光谱表征了ＰＰ接枝产物,并用差示扫描量热法研究了接枝前后ＰＰ结晶性能的变化。