熔融法制备EPDM-g-GMA及其对PEN脆韧转变的研究

利用Haake流变仪对(乙烯／丙烯／二烯)共聚物(EPDM)进行熔融接枝甲基丙烯酸缩水甘油酯(GMA),考察了单体、引发剂(DCP)用量对接枝率的影响。结果表明,随着DCP用量的增加,接枝率增大;随着GMA用量的增加,接枝率趋于一个平衡值。聚萘二甲酸乙二酯(PEN)／EPDM-g-GMA共混物的脆韧转变主要受温度和EPDM-g-GMA用量的影响,增加EPDM-g-GMA用量可以降低PEN／EPDM-g-GMA共混物的脆韧转变温度。     

聚丙烯接枝衣康酸增容PA6／PP共混物性能及形态研究

采用反应型双螺杆挤出机和熔融接枝技术制备了一系列聚丙烯（PP）接枝物，包括单一单体接枝物PP接枝衣康酸（PP-g-ITA）和双单体接枝物PP接枝ITA和苯乙烯[PP-g-（ITA-co-St）]，通过红外光谱和热分析研究了PP接枝物的结构，并研究了PP接枝物的接枝率和熔体流动速率与单体和引发剂用量的关系。通过反应挤出制备了PP接枝物增容PA6／PP共混物，研究了增容共混物的力学性能和形态结构。结果显示：加入接枝物后，共混体系的冲击强度明显提高；SEM观察表明，接枝物的加入能明显改善增容共混物的两相界面结合状况，降低共混物的分散相尺寸，改善体系的分散状况，共混物的两相界面变得模糊，相容性得到明显提高；DSC测试表明，加入接枝物后，共混物中PA6组分的结晶度下降，PP组合的结晶度上升。表明PP-g-ITA是PA6／PP共混体系有效的增容剂兼增韧剂。     

PBT/EPDM/EPDM-g-GMA共混物的形态与性能研究

采用熔融接枝法,在三元乙丙橡胶(EPDM)上接枝甲基丙烯酸缩水甘油酯(EPDM-g-GMA),用作EPDM增韧聚对苯二甲酸丁二醇酯(PBT)的增容剂。通过红外光谱表征证实了接枝反应的发生。考察了EPDM-g-GMA的引入对PBT/EPDM/EPDM-g-GMA共混物力学性能、形态结构、动态力学性能的影响。结果表明,随着EPDM-g-GMA含量的增加,EPDM在PBT中的分散相粒径更加细化,两相玻璃化转变温度的差值减小,PBT与EPDM间的相容性增加,共混物的缺口冲击强度显著提高,PBT能够被有效增韧。PBT/EPDM/EPDM-g-GMA的质量比为75/15/10时,体系的韧性最好。     

聚丙烯/含氟聚丙烯层状共混物的制备

采用熔融接枝技术制备含氟聚丙烯（FPP），然后将聚丙烯（PP）与FPP共混造粒制备PP／FPP共混物。用锥板流变仪分析PP和FPP的流变行为，探讨PP／FPP共混物层状形态形成的条件；用扫描电子显微镜、紫外光测试仪和万能材料试验机分析PP／FPP共混物层状形态、抗紫外光辐射性能和力学性能。结果表明，在200℃．剪切速率为125s^-1时，PP和FPP的流变曲线相交于一点，此条件有利于PP／FPP共混物形成层状形态。与纯PP相比，PP／FPP共混物的力学性能和抗紫外光透过能力明显提高。     

丙烯酸和苯乙烯改性PP/PS结晶与熔融行为

制备了苯乙烯（St）、St与丙烯酸（AA）混合物、丙烯酸接枝聚丙烯（PP-g-AA）改性聚丙烯／聚苯乙烯（PP／PS）共混物以及AA，St改性PP（原位形成PP／PS共混物）。用差示扫描量热仪（DSC）研究了3种改性方法对共混物中PP结晶与熔融行为的影响。结果表明，PS对PP的结晶与熔融温度影响不大，PP-g-AA则提高共混物中PP的结晶温度。St以及St与AA混合单体对PP／PS中PP结晶温度影响不大，但AA改性提高PP／PS中PP结晶温度。St加入PP导致PP结晶温度下降，St与AA混合单体原位聚合则提高PP的结晶温度。改性对共混物中PP的熔融温度影响不大，但是熔融峰形与结晶温度高低有关。红外光谱证实St与AA混合单体改性PP中有PP-g-AA形成，但改性共混物中没有PP-g-AA形成。     

一步法反应共混就地生成PP／AS合金的研究

在布拉本达中进行PP／AS熔融共混时加入小分子过氧化物DCP,希望发生接枝反应。通过研究DCP加入量、反应共混温度对共混中接枝反应的影响,设定了反应共混的工艺条件。共混物相形态观测及分离PP、AS两相后的红外测定表明,在设定的工艺条件下加入DCP进行共混,的确有效引发了共混过程中的接枝反应,生成一定量的接枝物并显著改善了共混物的相形态。另外,根据红外测定结果和反应共混物的熔体流动速率的测定,得到PP／AS配比对反应共混物熔融流变特性进而对接枝反应的影响。     

PP-g-GMA的制备及其增容PP/PA6共混物的性能

通过熔融接枝反应制备了甲基丙烯酸缩水甘油酯接枝聚丙烯（PP-g-GMA）,并将其作为聚丙烯/聚酰胺6（PP/PA6）共混物的相容剂,研究了PP-g-GMA对PP/PA6共混物的力学性能及形态结构的影响。结果表明,采用滴定法测得PP-g-GMA接枝率为3.35 %;当PP-g-GMA的添加量为4 %（质量分数,下同）和8 %时,PP/PA6/PP-g-GMA共混物的拉伸强度和缺口冲击强度分别较PP/PA6共混物提高了32.4 %和60.4 %;PP-g-GMA显著改善了PP/PA6 共混物的界面相容性,是PP/PA6共混物的有效增容剂。     

新型聚丙烯熔融接枝物增容PP／PA6共混物

本文研究了聚丙烯熔融接枝马来酸酐和不饱和羧酸混合单体对PP／PA6共混物的增容作用。研究结果表明,该接枝物是PP／PA6共混物的有效增容剂,能显著提高共混物的力学性能;接枝物的接枝率和用量影响增容共混物的力学性能;用接枝物增容后,PP／PA6表现更强的假塑性行为。溶融粘度增加,粘流活化能增加;随着接枝物用量的增加,共混物的MFI下降。     

MAH熔融接枝LDPE及其产物在PC／HDPE共混物中的应用研究

利用熔融接枝的方法对于马来酸酐（MAH）接枝低密度聚乙烯（LDPE）的反应规律进行了研究，并对接枝产物（LDPE－g-MAH)在聚碳酸酯／高密度聚乙烯（PC／HDPE）（80／20）共混物的影响进行了研究。探讨了MAH用量在1.25-10份，DCP用量为0.125-1份范围内接枝产物中接枝率和凝胶的变化规律。接枝产物在PC／HDPE（80／20）共混物应用结果表明，接枝率为0.8%的接枝产物对PC／HDPE（80／20）共混物的增容作用优于0.3%的接枝产物。PC／HDPE（80／20）共混物的断裂伸长率和冲击强度随着接枝产物的用量的增加而增大。而拉伸强度在接枝产物用量为1.2份时出现极大值。扫描电子显微镜观察表明LDPE－g-MAH能够有效改善PC／HDPE（80／20）共混物的相分散形态。     

PP-g-(GMA-co-St)增容PVC/PP共混物的研究

制备了一种新型的多单体接枝PP[PP-g-（GMA—co—St）]，研究了其对聚氯乙烯／聚丙烯（PVC／PP）共混体系的增容作用。讨论了接枝PP用量对共混物的界面相互作用、力学性能、耐热变形性能和加工流变性能的影响，并通过扫描电镜（SEM）对共混物的微观相结构进行了观察。结果表明，该接枝PP对PVC／PP共混体系有较好的增容效果，接枝PP的加入使共混物的界面相互作用增强。共混物的力学性能在接枝PP用量为20份时最佳；熔体流动速率在其质量分数为20％后下降缓慢，共混物的耐热变形性能随PP—g-（GMA—co—St）用量的增加而增强。     

EPDM增韧PET的研究

在引发剂过氧化二异丙苯(DCP)的作用下，通过添加少量界面增容剂苯乙烯(St)提高接枝率，使甲基丙烯酸缩水甘油酯(GMA)与(乙烯／丙烯／二烯)共聚物(EPDM)反应，得到接枝物EPDM—g—GMA，将EPDM—g—GMA与PET共混，以提高共混体系的冲击强度。探讨了不同含量的EPDM—g—GMA对共混体系力学性能的影响。结果表明，随着EPDM—g—GMA含量的增加，共混体系的缺口冲击强度显著提高，当其含量为50％时，材料的缺口冲击强度为344．9J／m，约为纯PET的12倍；拉伸强度、弯曲强度和弯曲弹性模量出现一定程度的下降；EPDM—g—GMA含量为20％～30％时．材料的综合力学性能较好。     

PP／PET／EPDM-g-GMA共混物结构与性能研究

通过反应共混制备了PP／PET／EPDM—g-GMA共混物。用扫描电镜和图像处理软件对共混物形貌进行定性和定量分析，用偏光显微镜观察共混物等温结晶形态，最后测量共混物的力学性能。结果表明：在PP／PET共混物中加入EPDM-g—GMA后，两相相容性改善，进一步加入成核剂后分散相尺寸更小、粒径分布更均匀；PP球晶随PET的混入而减小；在PP／PET体系中加入EPDM-g—GMA起到反应增容和橡胶增韧的协同效应，使缺口冲击强度由未加增容剂时的2．0kJ／m^2提高至6．6k．1／m^2，弹性模量较PP提高了38％；PP／PET共混物的拉伸强度随PET含量的增加下降，在相同PET含量的情况下，加入EPDM—g-GMA后，共混物的拉伸强度与未增容体系基本一致。     

Rheology and morphology of polypropylene in situ grafted and blended with methyl methacrylate/n‐buthylacrylate copolymer

The rheology and morphology of polypropylene (PP) modified by grafting and blending with vinyl monomers were studied in this work. The PP powder was impregnated by mixture of methyl methacrylate (MMA)/n‐buthylacrylate (n‐BA) and copolymerized with azobisisobutyronitrile (AIBN) initiator. The simultaneous grafting and blending of PP with MMA‐co‐n‐BA copolymers were performed in a corotating, 40 L/D, twin‐screw extruder in the presence of dicumyl peroxide. The Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to verify the grafting level and dispersion state of MMA/n‐BA copolymer on PP matrix, respectively, and their rheological properties were studied. It is observed that MMA/n‐BA copolymer is finely dispersed in the PP matrix. In this way, PP can be grafted, blended, and simultaneously compatibilized with polar copolymers, as is seen in SEM images. The results showed that by increasing acrylate monomers grafting on to PP increased. The same trend was observed for AIBN initiator. The gel content of samples with 25% monomers showed an increased from 0.7% to 3.5% by increasing AIBN from 0.2% to 0.4%. The grafting reaction took place with chain scission of PP molecules and also cross‐linking reactions. The optimum grafting of 7.3% with lowest chain scission and cross‐linking were obtained for samples containing 15 wt% monomer and 0.3% AIBN initiator. J. VINYL ADDIT. TECHNOL., 21:290–298, 2015. © 2014 Society of Plastics Engineers     

三元乙丙橡胶与尼龙树脂的增容共混

以甲基丙烯酸缩水甘油酯为接枝单体、过氧化二异丙苯为引发剂对三元乙丙橡胶（EPDM）进行熔融接枝。用傅里叶红外光谱（FTIR）对接枝产物进行了表征,分析测试了共混硫化胶的力学性能和微观结构。结果表明,随着共混体系中接枝EPDM用量的增加,EPDM与尼龙树脂的相容性不断改善,尼龙颗粒作为分散相在EPDM中分散得更加均匀和细致化,共混硫化胶的力学性能得到进一步提高,尼龙树脂原位生成的短纤维可明显提高共混硫化胶的撕裂强度,同时使其保持了弹性体高伸长率的特性。     

PP熔体接枝物改善HPVC/PP共混物的相容性

采用PP熔体接枝物改善HPVC/PP共混物的相容性。考察了共混比、不饱和极性单体、PP熔体挤出接枝物、增塑剂及EPDM用量对共混物力学性能的影响。     

PB-g-SAN接枝粉料的含胶量对ABS性能的影响

通过种子乳液聚合合成了一系列含胶量不同的聚丁二烯接枝(苯乙烯／丙烯腈)共聚物(PB-g-SAN)接枝粉料。考察了PB—g-SAN接枝粉料的含肢量对其接枝率的影响。将PB-g-SAN接枝粉料与SAN共混制备ABS，控制二者比例使每批ABS含胶量相同，均为15％。研究了PB—g—SAN接枝粉料的含胶量对ABS性能的影响。发现PB—g-SAN接枝粉料的含胶量在60％时，ABS的力学性能最好。     

PP-g-MAH对PP/PA6共混物的增容作用

采用熔融接枝法,考察了单体和引发剂用量对聚丙烯(PP)/马来酸酐(MAH)接枝物接枝率的影响。将PP-g-MAH作为PP/尼龙6(PA6)共混物的增容剂,并利用SEM、XRD、DSC-TGA和万能试验机等测试手段对PP-g-MAH增容改性PP/PA6共混体系进行了研究。结果表明,PP-g-MAH接枝物对PP/PA6共混物具有良好的增容效果,PP结晶得到细化,共混物的力学性能和耐高温性能得到改善。     

Influences of Grafted Side Chains on the Viscoelastic Behavior of Ternary Graft Copolymers

The novel ternary graft copolymers with long grafted side chains were prepared by solid phase grafting maleic anhydride (MAH), methyl methacrylate (MMA), and butyl acrylate (BA) onto polypropylene (PP). GPC was employed to show the length of the grafted side chains. The viscoelastic behavior was investigated by DMA. The results showed that the storage modulus and the loss modulus decreased with increase of the length of the grafted side chains but the α relaxation characterized by tanδ has no distinct change after various grafting. The distinct change of the internal damping of the graft copolymers was characterized by Cole-Cole curves. The storage modulus was successfully superposed according to the WLF and VFTH equations, which are suitable to describe the TTS principle for these ternary graft copolymers. When the weight percentage of MAH/MMA/BA was 6/6/2, the PP matrix had been overwhelmed by the grafted side chains, resulting in the change of the matrix properties and the dramatic increase of activation energy which was calculated by the Arrhenius equation. Meanwhile, the length of the grafted side chains was long enough to be discovered by TGA and DTG.     

Comparison of maleic anhydride grafting onto powder and granular polypropylene in the melt by reactive extrusion

The grafting of powder and granular polypropylene (PP) with maleic anhydride (MA) was investigated in a reactive extrusion process with dicumyl peroxide (DCP) as an initiator. The effects of the MA and DCP contents in the feed on grafting were investigated. Under the experimental conditions applied in this study, the grafted monomer unit content was varied from 0.023 to 0.5%. The MA grafting efficiency of powder PP was higher than that obtained for the granular form of PP. In general, the grafting degree first increased with the MA or DCP content in the feed, then reached a maximum value, and finally decreased because of several possible alternative reactions during the grafting. The grafting of powder PP was more successful because of better initial mixing and less diffusional resistance during the grafting. An increase in the MA content in the feed caused significant reductions in the melt‐flow index of the graft copolymers. The results obtained with Fourier transform infrared, differential scanning calorimetry, and X‐ray powder diffraction analyses indicated that the structure, macrotacticity, crystallinity, crystallization, and thermal behavior of PP changed with grafting and depended on the grafting degree. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3675–3684, 2004