苯乙烯/二乙烯苯协助马来酸酐熔融接枝聚丙烯研究

采用液-固溶胀的方法将马来酸酐(MAH)、共单体[苯乙烯(St)、二乙烯苯(DVB)]和引发剂过氧化二异丙苯分散到聚丙烯(PP)颗粒内部,利用流变仪研究了共单体协助MAH熔融接枝PP反应,采用红外光谱、热重分析和水接触角对接枝物的结构及性能进行分析,并对接枝反应机理加以探讨。结果表明,在最优反应条件下,添加St时接枝物的MAH接枝率和凝胶率分别为2.25%、1.56%;添加DVB时接枝物的MAH接枝率和凝胶率分别为3.06%、46.31%,并且接枝物的热稳定性和极性均有不同程度提高;接枝机理分析认为,在接枝反应时共单体首先接枝到PP链上,有效抑制了PP的降解,并与MAH主要以共聚形式接枝到PP主链上;DVB在分子结构上比St多了一个碳碳双键,一方面显著提高MAH接枝率,另一方面明显增大接枝PP大分子自由基间双基偶合终止的机会。     

聚丙烯固相接枝马来酸酐的接枝率影响因素的研究

研究了聚丙烯(PP)固相接枝马来酸酐(MAH)的反应温度,MAH和引发剂(BPO)用量等对产物接枝率和熔体质量流动速率等的影响.结果表明:120℃左右是制备高接枝率产物的最适宜反应温度;MAH和BPO用量分别为10%和5%左右时接枝产物的接枝率相对较高,同时其熔体质量流动速率和接枝效率也较为适当和合理;溶胀PP固相粒子的二甲苯用量也应适当控制,过量会造成操作及对接枝率不利等问题;接枝产物的熔点比PP纯样的低,而MAH的引入有利于结晶成核.     

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。     

蒙脱土对聚丙烯熔融接枝马来酸酐的影响

在聚丙烯熔融接枝马来酸酐(MAH)中引入有机蒙脱土(OMMT),讨论了OMMT/DCP(1∶1)、MAH的加入量对PP接枝率以及分子量的影响。结果表明PP接枝MAH的接枝率大大提高,减小了PP链的裂解。     

悬浮法合成马来酸酐接枝聚丙烯

采用水相悬浮法制备了马来酸酐(MAH)接枝聚丙烯(PP),以过氧化苯甲酰(BPO)为引发剂,考察了溶胀时间、接枝时间、界面剂的用量、引发剂和单体用量对聚丙烯接枝率(Gr)的影响。确定最佳接枝条件为:溶胀时间2.5h,反应时间3h,界面剂质量分数8%,引发剂质量分数3%,单体质量分数12%,此时可得到接枝率为1.9%的PP-g-MAH。     

聚丙烯水相悬浮接枝双单体苯乙烯和马来酸酐

以过氧化苯甲酰(BPO)为引发剂,采用水相悬浮法制备苯乙烯(St)、马来酸酐(MAH)双单体接枝聚丙烯共聚物(PP-g-St/MAH),结果表明,较优的接枝反应条件为BPO/St/MAH/水/PP投料质量比0.04/1.00/1.00/25.00/10.00,60℃溶胀2 h后90℃反应5 h.在此条件下,产物接枝率为8.97%,接枝效率为44.85%.     

改性PP的研究与应用

用马来酸酐(MAH)对聚丙烯(PP)进行接枝改性,制得改性PP膜。系统研究了反应温度、反应时间、引发剂(过氧化二苯甲酰)和单体(MAH)等对PP膜接枝率的影响。结果表明:改性后的PP膜性能得到提高。     

马来酸酐与α-甲基苯乙烯双单体接枝PP

采用溶液接枝制备马来酸酐(MAH)与α-甲基苯乙烯(α-MS)双单体接枝聚丙烯(PP)共聚物[PP-g-(MAH-α-MS)],通过化学滴定、红外光谱、广角X射线衍射、热失重-差示扫描量热同步热分析,研究了α-MS作为共聚单体对MAH接枝PP(PP-g-MAH)的接枝率和热性能的影响。固定MAH用量,加入适量α-MS可提高MAH在PP上的接枝率,当n(α-MS)/n(MAH)为1.00时,接枝率达到最大值,与单独使用MAH时的接枝率相比提高了约98%;PP-g-(MAH-α-MS)的晶粒尺寸较PP-g-MAH有所增加,熔点有所下降,而热稳定性提高。     

PE/PP共混物熔融接枝马来酸酐的研究

研究了聚乙烯(PE)和聚丙烯(PP)共混物接枝马来酸酐(MAH)时，引发剂(DCP)、接枝单体(MAH)和PP用量对接枝率的影响。结果表明，DCP与MAH的交互作用是影响接枝率的重要因素，在低DCP、MAH用量时，它们之间的交互作用并不明显，当用量均提高至一定程度后，且DCP用量为MAH用量的10％时，产物的接枝效率最高。在体系中加入适当粘度和结构的PP，可以获得接枝率变化不大，而熔体质量流动速率明显增大的接枝物。     

反应挤出制备接枝聚丙烯研究

以过氧化二异丙苯(DCP)为引发剂,利用反应挤出技术将马来酸酐(MAH)接枝到聚丙烯(PP)分子链上。详细考查了接枝产物的结构;MAH/DCP配比及反应挤出条件对接枝率的影响;接枝产物的流变性能。结果表明:在适宜的加工条件下,当PP/MAH/DCP的质量比为100∶3.5∶0.3时,可获得较高的接枝率。并且接枝产物的流变性能与PP一样为假塑性流体。     

水悬浮自搅拌体系中马来酸酐接枝聚丙烯的合成

在聚丙烯小球水悬浮液中以过氧化二苯甲酰 (BPO)为引发剂 ,利用水悬浮液沸点下的沸腾搅拌效应制备了接枝率为 9.0 6 %的马来酸酐 (MAH)接枝聚丙烯 (MAH - g -PP)小球 .用正交实验考察了反应时间、MAH及BPO用量对接枝率的影响规律 ,并用红外光谱对MAH -g -PP接枝共聚物进行了表征 .吸附实验结果进一步表明 ,与未接枝PP相比 ,MAH - g -PP对极性物质如水、Cu^{2 +} 、染料、糖化酶的亲合力大为提高 .     

聚丙烯——马来酸酐／聚己内酯三元接枝物的合成及其热分析研究

采用熔融法合成了聚丙烯—马来酸酐／聚己内酯（ＰＰ－ｇ－ＭＡＨ／ＰＣＬ）三元接枝共聚物。用富里叶红外光谱（ＦＴＩＲ）表征了接枝共聚物的化学结构,用峰高法测定了产物的接枝率。同时,考察了接枝反应时间和ＰＣＬ的分子量对接枝率的影响。并以示差扫描量热法（ＤＳＣ）对其热性能进行了分析。结果表明,ＰＣＬ的引入及其接枝率对ＰＰ－ｇ－ＭＡＨ的热性质有一定的影响,但分子量较低时将导致此接枝共聚物的结晶度和熔融温度进一步下降。     

PP–PP‐g‐MAH–Org‐MMT nanocomposites. I. Intercalation behavior and microstructure

The melt‐direct intercalation method was employed to prepare poly(propylene) (PP)–maleic anhydride grafted poly(propylene) (PP‐g‐MAH)–organic‐montmorillonite (Org‐MMT) nanocomposites. X‐ray diffractometry (XRD) was used to investigate the intercalation effect, crystallite size, and crystal cell parameter in these composites. Two kinds of maleated PP, with graft efficiencies of 0.6 and 0.9 wt %, and two sorts of manufacturing processes were used to prepare nanocomposites and then to investigate their effects on intercalation behavior. The results showed that the intercalation effect was enhanced by increasing the content of PP‐g‐MAH, using maleated PP with higher graft efficiency, and adopting the mold process. The crystallite size of nanocomposites perpendicular to the crystalline plane, such as (040), (130), (111), and (041), reached the minimum value when the content of PP‐g‐MAH was 20 wt %. This result indicated that the crystallite size of PP in nanocomposites decreased by proper addition of PP‐g‐MAH. Maximum values in tensile strength (40.2 MPa) and impact strength (24.3 J/m) were achieved when the content of PP‐g‐MAH was 10 and 20%, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3225–3231, 2003     

超声波作用下PP固相接枝马来酸酐研究

本实验利用超声波的分散原理,利用固相法粉末状聚丙烯接枝马来酸酐,以水为分散剂,丙酮为相面相溶剂,过硫酸氨[（NH）42S2O8]为引发剂,制备MAH固相接枝PP。研究了引发剂ASP用量、单体MAH用量、反应时间和比表面积等对接枝物接枝率的影响。结果表明,MAH的接枝率随引发剂APS用量的增加而先增加后下降;随MAH用量的增大,产物的接枝率先增大,当达到一个最高值后随着MAH用量的进一步增大,接枝率反而下降,但下降得并不明显。     

Improvements of polypropylene grafted maleic anhydride with ultrasonication, pre-irradiation and co-irradiation methods

This paper presented many improvements of polypropylene (PP) grafted maleic anhydride (MAH), including how to increase graft degree (G) and graft efficiency (G _E ) of MAH onto PP and how to reduce side reactions during grafting. Three grafting methods ultrasonication, pre-irradiation and co-irradiation were employed, and a lot of additives were adopted in our research, such as styrene (St), ethyl benzoate, dibutyl phthalate (DBP), 2,2′-bipyridine, divinylbenzene (DVB), benzoyl peroxide (BPO) and p-hydroquinone. The effects of the different grafting methods and additives were determined by G and G _E values, viscosity, FTIR and DSC. Experimental results showed that the highest G value was obtained in co-irradiation method in the presence of St, and side reactions could be also reduced. The best reflux time for G value measuring, the storage time on G and batch feeding times of MAH on G in pre-irradiation method, and the mechanism of PP grafted MAH were all studied.     

Styrene‐assisted free‐radical graft copolymerization of maleic anhydride onto polypropylene in supercritical carbon dioxide

The free‐radical graft copolymerization of maleic anhydride (MAH) onto polypropylene (PP) with the assistance of styrene (St) in supercritical carbon dioxide (CO₂) was studied. The effects of the St concentration and initiator concentration on the functionality degree of the grafted PP in supercritical CO₂ were investigated. The addition of St drastically increased the MAH functionality degree, which reached a maximum when the molar ratio of MAH and St was 1:1. St, an electron‐donating monomer, could interact with MAH through charge‐transfer complexes to form the St–MAH copolymer (SMA), which could then react with PP macroradicals to produce branches by termination between radicals. There was SMA in the grafting reaction system characterized by Fourier transform infrared and differential scanning calorimetry. Furthermore, the highest MAH functionality degree was obtained when the concentration of 2,2′‐azobisisobutyronitrile (AIBN) was 0.6 wt % based on PP. The effects of the temperature and pressure of supercritical CO₂ on the functionality degree of the grafted PP were analyzed. An increase in the temperature accelerated the decomposition rate constant of AIBN, thereby promoting the grafting reaction. In addition, an increase in the temperature increased the diffusion of monomers and radicals in the disperse reaction system of supercritical CO₂. The highest degree of functionality was found at 80°C. Also, the functionality degree of grafted PP decreased with an increase in the pressure of supercritical CO₂ within the experimental range. The morphologies of pure PP and grafted PP were significantly different under polarizing optical microscopy. The PP spherulites were about 38 μm in size, and the grafted PP spherulites were significantly reduced because of heterogeneous nucleation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 853–860, 2003     

三单体接枝共聚物对PP/云母填充体系性能的影响

将固相法接枝合成的聚丙烯与甲基丙烯酸甲酯／马来酸酐／丙烯酸丁酯的接枝共聚物PP-g-MMA/MAH/BA应用于PP／云母填充体系。研究接枝物对体系的力学性能、微观形态、热性能、加工性能及表面性能等的影响。结果表明，在PP／云母填充体系中加入适当的三单体接枝共聚物，可提高体系的拉伸强度、弯曲强度、维卡软化点及表面极性，并降低制品的成型收缩率；同时，体系的加工性能也得到改善。     

PP熔融接枝MAH的研究

以PP（EPS30R）为基体树脂,过氧化二异丙苯DCP为引发剂,在反应体系中加入少量的DMF（N,N-二甲基甲酰胺）,在双螺杆挤出机中于175℃-190℃进行了PP熔融接枝MAH的反应。用红外光谱表征了接枝反应的存在,并考察了引发剂用量、N,N-二甲基甲酰胺（DMF）的用量、单体用量对接枝反应的影响。研究表明：DMF能抑制PP的降解,并且确定了较佳的原料配比为m（PP）：in（MAH）：m（DMF）：In（DCP）：100：3：0．6：0．4,其接枝率可达2．95％。