苯乙烯在POE接枝GMA中的作用及其对增韧PBT效果的影响

采用苯乙烯(St)为辅助接枝单体,在聚烯烃弹性体(POE)上熔融接枝甲基丙烯酸缩水甘油酯(GMA),制备了POE-g-GMA,通过红外光谱表征证实了接枝反应的发生,考察了St的引入对POE-g-GMA接枝率、熔体流动速率以及POE-g-GMA增韧聚对苯二甲酸丁二醇酯(PBT)的影响。结果表明,在m(St)/m(GMA)为1时POE-g-GMA接枝率达到最大值,为1.057%;随着St用量的增加,接枝物的熔体流动速率持续降低;St的引入使POE相区尺寸明显减小,POE分散相与PBT基体间的相容性明显改善,共混物的冲击强度显著提高,PBT得到有效增韧。     

原位熔融接枝制备POE-g-GMA相容剂及在PA6/POE共混体系中的应用

采用原位熔融接枝法制备了接枝率为0.45%的POE-g-GMA相容剂,并熔融挤出制备了PA6/POE-g-GMA/POE共混物。同时利用DSC、XRD、TG、SEM以及微机控制万能电子试验机测试了共混物的微观结构、热性能及力学性能。结果表明,当POE-g-GMA、POE用量均为10%时,共混体系的结晶温度有所降低,分解峰温度升高,拉伸强度为58.4 MPa,简支梁缺口冲击强度为14.2 kJ/m²。相比纯PA6和PA6/POE的冲击强度分别提升了132.8%、71.1%,拉伸强度小幅降低。自制相容剂可显著降低POE在PA6基体中的分散性,降低POE分散相尺寸,共混物呈现“韧窝”态的韧性断裂特征。     

POE熔融接枝GMA的制备及其与PBT共混增韧

在双螺杆挤出机上采用熔融接枝法制备了POE-g-GMA和POE-g-(GMA-co-St),考察了POE、POE-g-GMA和POE-g-(GMA-co-St)对聚对苯二甲酸丁二醇酯(PBT)的增韧作用.结果表明POE和单组分接枝的POE-g-GMA对PBT的缺口冲击韧性的改善作用都不大;而双组分接枝的POE-g-(GMA-co-St)对PBT具有显著的增韧作用.当弹性体POE-g-(GMA-co-St)用量为15%时,共混物的缺口冲击强度为45.84 kJ/m2,是缺口冲击强度为1.28 kJ/m2的纯PBT的35倍多.SEM显示,PBT/POE-g-(GMA-co-St)共混体系中分散相比PBT/POE-g-GMA共混体系的分散相具有更好的分散性.同时对比了几种外来增韧剂对PBT性能的影响.     

环氧官能化弹性体增韧PET的研究

通过熔融接枝反应,分别在弹性体乙烯/辛烯共聚物(POE)、三元乙丙橡胶(EPDM)、苯乙烯-乙烯-丁二烯-苯乙烯共聚物(SEBS)上成功接枝了甲基丙烯酸环氧丙酯(GMA),制备出SEBS-g-GMA、EPDM-g-GMA、POE-g-GMA,考察了3种弹性体对聚对苯二甲酸乙二醇酯(PET)的增韧效果。结果表明:熔融接枝GMA后,在弹性体与PET之间引入了化学反应,明显减小了三种弹性体在PET中的分散相尺寸,降低了共混物的熔体质量流动速率,增加了PET与弹性体间的相容性。SEBS-g-GMA不能有效增韧PET,而POE-g-GMA与EPDM-g-GMA是PET的有效增韧剂。     

POE接枝MA增韧PBT的研究

用熔融接枝法制备的马来酸酐接枝乙烯-1-辛烯共聚物(POE-g-MA)对聚对苯二甲酸丁二醇酯(PBT)的增韧改性,研究了不同接枝率的POE-g-MA对PBT/POE-g-MA共混物力学性能、结构以及熔融结晶行为的影响。结果表明,POE接枝MA后可明显提高POE与PBT的相容性及PBT的冲击性能,但接枝率过高反而会影响界面黏结,使冲击性能降低。     

PBT与官能化POE共混过程中的增容反应研究

采用带流变槽的HAAKE流变仪研究了乙烯-辛烯共聚物（POE）和甲基丙烯酸缩水甘油酯接枝乙烯-辛烯共聚物（POE-g-GMA）与聚对苯二甲酸丁二醇酯（PBT）共混物的黏度随共混时间的变化过程，并对这两种共混物的断面形貌和力学性能进行对比分析。结果表明，由于POE-g-GMA能够与PBT发生原位增容反应，使得POE-g-GMA颗粒的粒径小、分散均匀，体系黏度随共混时间先长时间持续上升，然后保持不变，体系最终黏度也随着POE-g-GMA浓度升高而升高；然而在不发生反应的PBT／POE体系中，POE颗粒分散性差，颗粒粒径大，体系黏度受POE的浓度影响相对较小且随时间基本上保持不变。由于POE-g-GMA与PBT之间的增容反应使得PBT／POE-GMA的力学性能优于PBT／POE，并且冲击强度随POE-g-GMA浓度呈现两个阶段变化，即低于临界浓度时冲击强度缓慢升高，高于临界浓度时冲击强度快速升高。     

聚乳酸溶液接枝丙烯酸及与淀粉共混研究

通过溶液聚合法,合成了聚乳酸（PLA）与丙烯酸（AA）的接枝共聚物PLA-g-AA,用以改善PLA与淀粉熔融共混物的相容性。研究了不同的接枝工艺条件对共聚物接枝率的影响,并考察了接枝聚乳酸与淀粉共混物的力学性能和结晶性。结果表明,最佳工艺条件是淀粉含量70%、接枝物含量15%、反应温度170℃、反应时间10min。在此条件下共混物的拉伸强度可达到27.35MPa,弹性模量728.22MPa,断裂伸长率达到3.59%。     

植物油多元醇与L赖氨酸乙酯二异氰酸酯原位单体反应型增韧聚乳酸

以可生物降解的植物油多元醇（HM10100）和L-赖氨酸乙酯二异氰酸酯（LDI）作为反应性增韧单体,熔融共混过程中原位形成与聚乳酸（PLA）基体相容性良好、且分散均匀的交联聚氨酯弹性体增韧相,最终制备出一种新型全生物降解的增韧PLA材料,分别研究了2种反应型增韧单体总质量含量和它们之间异氰酸酯基团与羟基的等当量比（nNCO/nOH）对PLA共混物力学、结晶性能及冲击断面形貌的影响规律。结果表明,当2种增韧单体总含量为40 %（质量分数,下同）且nNCO/nOH =1:0.8时,共混物的缺口冲击强度最高,约为纯PLA的3.5倍;随着2种增韧单体总含量和官能团摩尔比的增加,共混物中PLA组分的冷结晶温度(Tcc)和玻璃化转变温度(Tg)增加。     

POE接枝衣康酸增容PA6/POE共混物性能及形态研究

以衣康酸（ITA）为接枝单体,采用双螺杆挤出机和熔融接枝技术制备了一系列乙烯-辛烯共聚物接枝物（POE-g-ITA）,通过红外光谱对接枝物的结构进行了表征,研究了引发剂和单体用量对POE-g-ITA接枝率和熔体流动速率的影响,当POE/ITA/过氧化二异丙苯（DCP）=94/6/0.36时,接枝率达到1.36 %;通过双螺杆挤出机将相容剂POE-g-ITA引入到聚酰胺6/乙烯-辛烯共聚物（PA6/POE）共混物中,研究了共混物的力学性能和形态结构。结果表明,加入5份（质量份数,下同）POE-g-ITA后,PA 6/POE共混物的冲击强度提高到纯PA 6的12.78倍,PA6与POE两相界面变得模糊,分散相尺寸明显减小,界面相互作用明显增强,相容性得到显著提高。     

POE-g-MAS增韧SAN树脂及其相容性

合成了乙烯-辛烯共聚物(POE)和甲基丙烯酸甲酯-丙烯腈-苯乙烯的接枝共聚物(POE-g-MAS).用POE-g-MAS与苯乙烯-丙烯腈共聚物(SAN)树脂共混制备了具有高抗冲击性能的SAN,POE-g-MAS共混物,研究了接枝链极性、接枝率和POE含量对共混物冲击性能的影响,当m(St)/m(MMA)/m(An)为10:70:20,接枝率为45.1%,w(POE)为25%时,共混物的缺口冲击强度达到56.1kJ/m2.用扫描电子显微镜和差示扫描量热仪研究表明,POE-g-MAS与SAN树脂有良好的相容性.     

Influence of Grafting Degree on the Morphology and Mechanical Properties of PA6/POE-g-GMA Blends

Poly(ethylene-1-octene) (POE) was functionalized to varying degrees with glycidyl methacrylate (GMA) by melt grafting processes. Fourier transform infrared spectra (FT-IR) and ¹H NMR spectra confirmed that glycidyl methacrylate was successfully grafted onto the POE. The data from GPC measure demonstrated that POE chains degraded during grafting process. The POE-g-GMA elastomers were used to toughen nylon. The mechanical properties, fracture surface morphology and the dispersal phase size were investigated. Results showed that the grafting degree strongly influenced the morphology, mechanical properties and the dispersal phase size of PA6/POE-g-GMA blends.     

界面增容剂的结构对PLA/PP共混体系界面状态及性能的影响

通过在聚乳酸(PLA)和聚丙烯(PP)共混体系中分别引入马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)和甲基丙烯酸缩水甘油酯接枝乙烯-辛烯共聚物(POE-g-GMA),制备出具有不同结构及性能的共混材料(PLA/PP/POE-g-MAH,PLA/PP/POE-g-GMA),并采用转矩流变仪、扫描电子显微镜、差示扫描量热仪、平板流变仪及电子万能试验机等研究了不同界面增容剂的结构对PLA/PP共混体系界面状态及性能的影响。结果表明,POE-g-MAH和POE-g-GMA均可改善PLA与PP的相界面形态,但与POE-g-GMA相比,POE-g-MAH的界面催化效率更高,对PLA/PP共混体系增容效果更好,其可诱导PLA与PP在界面处形成微交联结构,增强PLA与PP的界面相互作用,改善材料的机械性能,当添加4wt%的POE-g-MAH时,PLA/PP/POE-g-MAH共混物的拉伸强度达29.7 MPa,断裂伸长率提升至39.3%,较PLA/PP样品提高了8倍;并且共混材料的冲击强度随着POE-g-MAH含量的增加而增加,当其添加量为6wt%时,材料冲击强度达30.1 kJ/m2,材料具有较好的刚韧平衡性。     

POE-g-GMA的制备及其对纳米CaCO_3／PA66的增韧

采用熔融法制备乙烯-1-辛烯共聚物(POE)接枝甲基丙烯酸环氧丙酯(GMA),利用红外光谱对其结构进行表征。考察了GMA和过氧化二异丙苯(DCP)用量以及反应温度和反应时间对接枝率的影响,结果表明,GMA用量增加,接枝宰逐渐增大,熔体流动速率逐渐下降；隨着引发剂用量的增加,接技率也隨之增加；同时隨著反应温度和反应时间的变化,接枝率随之变化。然后采用熔融共混法制备了纳米CaCO_3／POE-g-GMA／PA66复合材科,研究了该体系的力学性能,结果表明,纳米CaCO_3和POE-g-GMA对PA66具有一定的增韧作用。     

rPET/POE/LDPE-g-AA复合材料的制备及性能

以回收聚对苯二甲酸乙二酯( rPET)为基体材料,乙烯-辛烯共聚物(POE)为增韧材料,丙烯酸接枝低密度聚乙烯( LDPE-g-AA)为增容剂,制备了rPET/POE/LDPE-g-AA复合材料.分析了POE、LDPE-g-AA对rPET 玻璃化转变温度、断面相结构、结晶性能、力学性能的影响.结果表明,加入POE...     

复合引发GMA熔融接枝POE及其增韧PBT的研究

采用双螺杆加工过程中的机械力引发同时添加引发剂的双重引发方法,研究了引发剂的用量、螺杆转速和接枝反应温度对甲基丙烯酸缩水甘油酯（GMA）接枝乙烯-辛烯共聚弹性体（POE）产物的接枝率、熔融指数的影响。对于单纯采用引发剂引发方法和引发剂与机械力双重引发方法所得接枝产物增韧聚对苯二甲酸丁二醇酯（PBT）的效果也进行了比较。后者在接枝物含量为30％时,可使PBT／POE—g—GMA共混材料的缺口冲击强度达到原未改性材料的22倍左右。     

Influences of ethylene–butylacrylate–glycidyl methacrylate on morphology and mechanical properties of poly(butylene terephthalate)/polyolefin elastomer blends

Elastomer ethylene–butylacrylate–glycidyl methacrylate (PTW) containing epoxy groups were chosen as toughening modifier for poly(butylene terephthalate) (PBT)/polyolefin elastomer (POE) blend. The morphology, thermal, and mechanical properties of the PBT/POE/PTW blend were studied. The infrared spectra of the blends proved that small parts of epoxy groups of PTW reacted with carboxylic acid or hydroxyl groups in PBT during melt blending, resulting in a grafted structure which tended to increase the viscosity and interfere with the crystallization process of the blend. The morphology observed by scanning electron microscopy revealed the dispersed POE particles were well distributed and the interaction between POE and PBT increased in the PBT/POE/PTW blends. Mechanical properties showed the addition of PTW could lead to a remarkable increase about 10‐times in impact strength with a small reduction in tensile strength of PBT/POE blends. Differential scanning calorimetry results showed with increasing PTW, the crystallization temperature (T_c) and crystallinity (X_c) decreased while the melting point (T_m) slightly increased. Dynamic mechanical thermal analysis spectra indicated that the presence of PTW could improve the compatibility of PBT/POE blends. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40660.     

不同增韧剂对PBT增韧改性的研究

利用双螺杆挤出机,采用聚乙烯-辛烯弹性体(POE)、聚乙烯-辛烯弹性体接技马来酸酐(POE-g-MAH)以及聚丙烯(PP)作为增韧剂与聚对苯二甲酸丁二醇酯(PBT)进行熔融共混,研究了不同增韧剂POE、POE-g-MAH和POE-PP对PBT共混物的力学性能、相容性和熔融结晶行为的影响。通过拉伸、冲击、熔体质量流动速率、硬度等性能测试以及红外光谱、X射线衍射仪(XRD)、差示扫描量热仪(DSC)等综合测试。结果表明,加入增韧剂对PBT具有良好的增韧效果,其中以PBT/POE/PP的增韧效果最明显。当PBT∶POE∶PP质量比为7∶3∶1时,共混物的缺口冲击强度增加8倍,红外表征显示,增韧改性可提高PBT的相容性,XRD测试表明,增韧剂对PBT复合材料的晶体结构没有影响,通过熔融增韧,提高其力学性能和加工性能。DSC图显示,增韧剂的加入可使共混物的结晶度降低。扫描电镜(SEM)表明,增韧剂的加入增加界面了结合力,提高了共混体系相容性。     

POE熔融接枝GMA的制备及其增韧PBT的应用研究

采用熔融接枝法制备聚烯烃热塑弹性体(POE)接枝甲基丙烯酸缩水甘油酯(GMA),将接枝物[POE-g-(GMA-g-St))]用于聚对苯二甲酸丁二醇酯(PBT)的增韧改性。研究了接枝物含量对共混物力学性能、结构以及熔融结晶行为的影响。结果表明:POE-g-(GMA-g-St)对PBT具有良好的增韧效果,当加入弹性体30%时,共混物的冲击强度为71.97 kJ/m2。SEM图像显示:作为分散相的接枝物在PBT基体中的尺寸更小且粒径分布更均匀。DSC图像显示出现两个熔融峰且随接枝物含量的增加其结晶度逐渐降低。     

High-toughening modification of polylactic acid by long-chain hyperbranched polymers

The hyperbranched polyester synthesized by “one-step method” was grafted with stearic acid to obtain long-chain hyperbranched polymers (LCHBPs) with a large number of long stearic acid chains at the end. By means of FTIR and ¹³C-NMR characterization, it was proved that stearic acids were grafted onto hyperbranched polyesters (HBPE) to yield LCHBPs successfully. It was determined by GPC and hydroxyl value titration that the number average molecular weight of HBPE was 4.86 × 10³ and the grafting rate of stearic acid was 47%. Polylactic acid (PLA)/LCHBPs blends were prepared by melt processing method. The results showed that comparing with neat PLA, the tensile strength of PLA/LCHBPs blends decreased slightly with the increase of LCHBPs, but still maintained a high level, while the elongation at break and the impact strength of the PLA with 3.0 phr LCHBPs were greatly improved by 1360.0% and 119.8%, respectively. In addition, the impacted fracture characteristics of PLA changed significantly from brittle fracture to ductile fracture after LCHBPs incorporation, with the formation of a large number of filamentous structures. Thus, LCHBPs was an excellent toughening modifier for PLA and the resulting blends with improved performance possess wider applications.     

Toughening of polylactic acid using styrene ethylene butylene styrene: Mechanical,thermal, and morphological studies

Polylactic acid, PLA, derived from renewable resources has gained great attention nowadays owing to their sustainability, biodegradability, superior property, and transparency. However, intrinsic brittleness and low toughness severely limits its variety of applications. Blending of PLA with other polymers is more economical and more flexible technique for the property improvement of PLA. In this study, Styrene Ethylene Butylene Styrene (SEBS) and Maleic Anhydride grafted SEBS (MA‐g‐SEBS) are used as toughening agents to study their effect for its toughness, high strength and heat resistance on PLA. PLA/SEBS and PLA/Maleic Anhydride grafted SEBS blends were prepared under four different compositions by melt mixing technique using a corotating twin–screw extruder after optimizing the mixing conditions. The mechanical properties of the blends such as tensile, flexural, and impact strengths were investigated using specimens prepared by injection molding process. The percentage elongation and impact strength of PLA/MA‐g‐SEBS blends were found to be increased significantly by 540 and 135%, respectively in comparison with virgin PLA and PLA/SEBS blends. However, tensile strength and modulus of PLA/SEBS and PLA/MA‐g‐SEBS blends decreased compared with pristine PLA. SEM behaviour supported the higher impact property of PLA with the incorporation of modified SEBS via multiple crazing and cavitation mechanisms. DSC study also supported greater compatibility between maleated SEBS and PLA. POLYM. ENG. SCI., 56:669–675, 2016. © 2016 Society of Plastics Engineers