PBAT/PLA薄膜的制备及性能研究

将聚乳酸（PLA）和聚对苯二甲酸-己二酸-丁二醇酯（PBAT）共混制备成共混材料,探讨了不同PLA含量对材料性能的影响。结果表明,PBAT/PLA共混材料中,随着PLA含量的增加,拉伸强度先降低后升高,当PLA含量为90 %时,拉伸强度达到60.12 MPa,而其断裂伸长率从703 %降低至8 %,由韧性材料逐渐转变为脆性材料;PLA含量为30 %时,性能变化出现拐点;PLA含量为50 %时出现明显相分离,且PLA的加入可以加速PBAT材料的结晶,使结晶温度由38 ℃提高至82 ℃;PBAT/PLA共混材料在PLA含量低于70 %时,都可以实现较好的吹膜过程,且薄膜材料的拉伸强度为39.59 MPa,断裂伸长率不低于137 %。     

PGA/PBAT复合材料的性能及应用研究

采用熔融共混法制备了一系列不同组分含量的聚乙醇酸（PGA）/聚对苯二甲酸-己二酸丁二醇酯（PBAT）复合材料,对复合材料的耐热性能、力学性能和水气阻隔性能进行了表征。结果表明,当PGA含量为80 %（质量分数,下同）时,注塑样条的拉伸强度为68.80 MPa、断裂伸长率为72.15 %、冲击强度为16.00 kJ/m²、负荷变形温度为120 °C,表明该复合材料可用于制备一次性餐具;当PGA含量为20 %时,吹塑薄膜的纵横向拉伸强度均在25 MPa以上,纵横向断裂伸长率均在600 %以上,表明该复合材料可用于生产膜袋产品;此外,随着PGA含量的增加,PGA/PBAT材料的水气阻隔性能也逐渐增加,其中含20 %PGA的PGA/PBAT复合膜的水蒸气透过率为纯PBAT薄膜的1/7。     

复合偶联剂改性碳酸钙对PBAT性能的影响

以聚对苯二甲酸己二酸丁二醇酯(PBAT)为基材,以改性碳酸钙(CaCO₃)为填料,采用熔融共混吹膜方式制备PBAT/改性CaCO₃复合材料,研究改性CaCO₃对PBAT薄膜性能的影响。结果表明：改性CaCO₃的加入提高复合材料的结晶温度、熔融温度以及结晶度。采用2%硅烷偶联剂和2%硬脂酸复配改性CaCO₃,PBAT/改性CaCO₃复合材料(M-4)结晶度最高且力学性能优异,横纵向拉伸强度分别为26.51 MPa和36.07 MPa;横纵向断裂伸长率分别为839.33%和462.44%;横纵向直角撕裂负荷分别为2.10和3.07;横纵向直角撕裂强度分别为101.40和136.01。2%铝酸酯和2%硬脂酸复配改性的CaCO₃提升复合材料的水蒸气阻隔性能,复合材料的水蒸气透过率较纯PBAT降低40.09%,水蒸气透过系数降低47.54%。加入改性CaCO₃,复合材料的储能模量、损耗模量和复数黏度均有所提高。     

PBAT的制备与性能

采用3种不同的制备方法合成聚(己二酸丁二醇酯/对苯二甲酸丁二醇酯)(PBAT),通过研究反应时间、温度以及不同合成方法对共聚物相对分子质量的影响,得出制备方法-(M1)为制备聚(己二酸丁二醇酯/对苯二甲酸丁二醇酯)的最佳工艺路线.利用FTIB、NMR研究PBAT共聚酯结构,及共聚物的热性能和流变性能.     

PLA/PBAT薄膜的制备及其降解性能研究

以过氧化二苯甲酰(BPO)为界面相容剂,采用熔融挤出、吹塑成型的方法制备了聚乳酸/己二酸-对苯二甲酸-丁二酯共聚物(PLA/PBAT)薄膜。通过力学性能检测和碱液加速降解试验研究了PBAT含量对PLA/PBAT薄膜力学性能及降解速率的影响;并运用红外光谱(FTIR)及动态力学分析(DMA)探究了降解机理。结果表明:随着PBAT含量的增加,PLA/PBAT复合薄膜的拉伸强度、拉伸模量及直角撕裂强度减小,断裂伸长率增大。PLA/PBAT复合薄膜的降解实质是酯键的水解。与降解前相比,降解后薄膜的储能模量大幅度降低,玻璃化转变温度略微下降。     

可生物降解TPS/PBAT复合材料的制备

将热塑性淀粉(TPS)与聚(对苯二甲酸丁二醇酯-己二酸丁二醇酯)(PBAT)熔融共混并挤出,制备了可完全生物降解的TPS/PBAT复合材料.采用X射线衍射仪和扫描电子显微镜研究了复合材料的微观结构与形态,测试了不同组分复合材料的性能.结果表明:加入PBAT后,复合材料的熔体流动性明显提高;拉伸强度从6.36 MPa先下降到3.31 MPa, 然后升高到12.98 MPa; PBAT的加入抑制了支链淀粉分子的重结晶, 降低了复合材料的吸水率.     

PBAT/磷石膏复合薄膜的制备与性能

采用熔融挤出流延法制备聚己二酸/对苯二甲酸丁二酯(PBAT)/磷石膏(PG)复合薄膜,利用热重分析仪、X射线衍射仪及扫描电子显微镜(SEM)等对PBAT/PG复合薄膜的性能与微观形貌进行表征.结果表明,PG微粉的加入量为40％ 时,PBAT/PG复合薄膜的拉伸强度高达19.4 MPa,与纯PBAT薄膜的拉伸强度相比提高...     

碳酸钙含量对PBAT薄膜性能的影响

用HAAKE双螺杆对聚己二酸/对苯二甲酸丁二醇酯(PBAT)与碳酸钙粉体共混挤出造粒,再进行吹膜.用热失重分析(TGA)、差示扫描量热仪(DSC)、万能材料试验机等表征了薄膜的力学性能.结果表明:碳酸钙加入后,PBAT薄膜的热降解反应活化能降低,熔点(Tm)升高;拉伸强度随碳酸钙含量的增加先升后降,综合考虑成本与性能问...     

MMA-co-GMA增容PBAT/PLA共混材料结构与性能

利用甲基丙烯酸甲酯-甲基丙烯酸缩水甘油酯无规共聚物(MG)为相容剂,采用熔融共混法制备了聚对苯二甲酸-己二酸丁二醇酯(PBAT)和聚乳酸(PLA)生物降解共混材料。MG中的环氧官能团与PBAT和PLA中的端基之间的增容反应生成PBAT-co-MG-co-PLA大分子相容剂提高二者之间的相容性。MG的加入导致PLA相的最大分解速率温度明显向高温方向移动,耐热性提高,而PBAT相最大分解速率温度几乎没有变化。MG的增容作用促进了PBAT相的均匀分散、较小的粒子尺寸和窄的分布。动态流变测试结果表明,PBAT/PLA/MG共混材料比PBAT/PLA共混物具有更高的复数黏度和储能模量,增容反应增加了界面相互作用和熔体强度。同PBAT/PLA共混材料相比,MG的增容作导致PBAT/PLA/MG共混物表现出更高的冲击韧性、断裂伸长率和拉伸强度。     

Preparation and properties of polyamide 6/polypropylene–vermiculite nanocomposite/polyamide 6 alloys

Polypropylene–vermiculite nanocomposites can be achieved by simple melt mixing of maleic anhydride‐modified vermiculite with polypropylene. Maleic anhydride acts either as a compatibilizer for the polymeric matrix or as a swelling agent for the silicate. Compatibilized blends are injection molded directly from polyamide 6 and polypropylene–vermiculite nanocomposites. Scanning electron microscopy observation reveals that a two‐phase structure consisting of polypropylene–vermiculite nanocomposite and polyamide 6 is formed in the blends. The absence of vermiculite reflections in the X‐ray powder diffraction patterns indicates that the polypropylene–vermiculite phase exhibits nanocomposite characteristics. Tensile test shows that the tensile modulus of the polymer alloy tends to increase with increasing polypropylene–vermiculite nanocomposite content. The tensile strength of composite containing 8 wt % vermiculite is higher than that of pure polyamide 6. Finally, the thermal properties of the nanocomposites are determined by dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetric measurements. The effects of maleic anhydride addition on the formation of polypropylene–vermiculite nanocomposite reinforcement and on the mechanical properties of composites are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2330–2337, 2002     

Preparation of organic vermiculite/polymethylmethacrylate nanocomposite featuring excellent mechanical and thermal properties via ultrasonic in situ polymerisation

To improve the dispersion of organically modified vermiculite (OVMT) in polymethylmethacrylate (PMMA), the method of ultrasonic in situ polymerization was introduced, and a series of OVMT/PMMA nanocomposites were successfully prepared. The structure, morphology, and mechanical and thermal properties of as-prepared sample had been investigated. Results showed that the assistance of ultrasonic irradiation could be beneficial for the good homogeneous dispersion and strong interfacial interaction of OVMT in PMMA. Consequently, the obtained nanocomposites showed better mechanical and thermal properties than those prepared without the assistance of ultrasonic irradiation. When the OVMT content was 3 wt.%, the nanocomposite prepared by ultrasonic in situ polymerization exhibited the Young's modulus, tensile strength, elongation at break and degradation temperatures for 5% and 50% weight loss of 1177 MPa, 65 MPa, 14%, 219.82ºC and 373.91ºC, respectively. These results suggested the great potential application of ultrasonic in situ polymerization for the synthesis of polymer/clay nanocomposite.     

ABS／SMA及ABS／SMA／PMMA的性能研究

研究了ABS／SMA和ABS／SMA／PMMA共混体系,确定了配比与合金的拉伸强度、冲击强度、断裂伸长率、模量、热变形温度、熔体流动速率等关系。结果表明：①ABS中引入SMA可以显著提高耐热性能,但同时合金的缺口冲击强度严重降低;②ABS中引入SMA可使合金的流动性能提高;③ABS／SMA体系中引入第三组分PMMA可以大幅度提高共混物的缺口冲击强度,同时使合金的耐热性能有所提高。     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

Preparation of phenolic resin/organized expanded vermiculite nanocomposite and its application in brake pad

Phenolic resin (PF)/organized expanded vermiculite (OEVMT) nanocomposite was prepared via melt intercalation with EVMT organically treated using benzyldimethyloctadecylammonium. The results of the PF/OEVMT structure characterized by X‐ray diffraction and transmission electron microscopy showed that the PF/OEVMT nanocomposite formed exfoliated and intercalated mixed structure. Thermogravimetric analysis indicated that the thermal decomposition temperature of the PF/OEVMT nanocomposite (482.6°C) was higher than that of pristine PF (433.9°C) in air atmosphere. The brake pad based on PF/OEVMT nanocomposite were also prepared. The friction and wear tests illustrated that the brake pad based on PF/OEVMT had more stable friction coefficient and lower wear rate than that of the brake pad based on PF. Scanning electron microscopy also showed that the brake pad based on PF/OEVMT nanocomposite has excellent high temperature wear‐resistance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and Characterization of Polyester Based on bis- (2- hydroxypropyl terephthalate)

Polyester based on bis- (2-hydroxypropyl terephthalate) (BHPT) and maleic anhydride (MA) was prepared and its structure confirmed by spectral analysis. The kinetic of the condensation reaction was investigated at three different temperatures (180–200°C) in the presence and the absence of p-toluene sulphonic acid (PTSA) as a catalyst. The reaction order was found to be second and third order in the presence and absence of the catalyst, respectively. The activation energy was calculated in both cases and was found to be 15.7 and 145.5 kJ mol^–1 in the presence and absence of the catalyst, respectively. The polyester was mixed with styrene monomer, and with methyl ethyl ketone peroxide (0.5 wt.%) as initiator and cobalt naphthenate (0.25 wt.%) as accelerator to obtain a styrenated resin with good mechanical properties. N-phenyl maleimide (NPMI) was also used together with styrene in different ratios to form a copolymer. No pronounced improvement in the mechanical and the thermal properties was found after the introduction of NPMI.     

Processing and properties of carbon nanotube/poly(methyl methacrylate) composite films

A systematic study of the reinforcement of single‐walled carbon nanotubes (SWNTs), multiwalled carbon nanotubes, and vapor‐grown carbon nanofibers (VGCNFs) in poly(methyl methacrylate) (PMMA) is reported. SWNT/PMMA composite films with various SWNT concentrations (from 0.5 to 50 wt % with respect to the weight of PMMA) were processed from nitromethane. Two types of SWNTs were used: SWNT‐A, which contained 35 wt % metal catalyst, and SWNT‐B, which contained about 2.4 wt % metal catalyst. Properties of different nanotubes containing composites were compared with 15 wt % carbon nanotubes (CNTs). Property enhancement included electrical conductivity, mechanical properties, and solvent resistance. The thermal degradation of PMMA in the presence of CNTs in air and nitrogen environments was studied. No variation in the thermal degradation behavior of PMMA/CNT was observed in nitrogen. The peak degradation temperature increased for the composites in air at low CNT loadings. Dynamic and thermomechanical properties were also studied. At a 35 wt % SWNT loading, a composite film exhibited good mechanical and electrical properties, good chemical resistance, and a very low coefficient of thermal expansion. Property improvements were rationalized in terms of the nanotube surface area. Composite films were also characterized with Raman spectroscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

马来酸酐和苯乙烯接枝改性对天然橡胶/聚丙烯共混物物理机械性能的影响

用动态硫化法制备了天然橡胶(NR)/聚丙烯(PP)热塑性弹性体(TPV)。研究了马来酸酐/苯乙烯/过氧化二异丙苯(MAH/St/DCP)多单体熔融接枝交联改性及纳米二氧化硅用量对NR/PP TPV物理机械性能的影响,讨论了NR/PP TPV的重复加工性能。结果表明,当MAH/St/DCP用量为3.750/1.875/0.375质量份、纳米二氧化硅用量为3质量份时,NR/PP TPV的物理机械性能最好,达到了国内外有关通用橡胶/PP TPV的水平,并且具有较好的重复加工性能。     

Preparation and balanced mechanical properties of solid and foamed isotactic polypropylene/SEBS composites

This study presents a self-designed foaming apparatus and routes to manufacture foamed isotactic polypropylene (iPP) blends with uniform and dense cells, using styrene-ethylene-butadiene-styrene (SEBS) block copolymer as toughening additive. The addition of SEBS can clearly enhance the impact strength of solid iPP, iPP blends with a 20 wt% SEBS has obtained high notched impact strength of 75 kJ/m², which is ca. 16 times larger than that of neat iPP. Relatively fine microcellular iPP-SEBS foams with the average cell size of several micrometers, and the cell density of 10⁹ cells/cm³ were fabricated using a batch foaming procedure. Moreover, using our self-designed mold and compression foaming method, iPP-SEBS foams with balanced mechanical properties were produced. With the increasing of SEBS, tensile strength and flexural strength were slightly decreased, but the impact strength was increased clearly. The balanced mechanical properties between stiffness and toughness were achieved after compression foaming.     

Preparation of flexible and transparent SMA films by simple composite with MBS potential for negative birefringence compensator

The brittleness of poly(styrene maleic anhydride) (SMA) was improved by compositing with elastic poly(methyl methacrylate‐butadiene‐styrene) (MBS) to develop it into optical film. Transparent and flexible SMA films were prepared, and the flexibility of them was checked by folding endurance test and folding bend. The transparence of SMAMBS films were proved by the transmittance and haze measurements. In actual view, the letters could be clearly observed while they were covered by prepared films. The thermal stability of them was confirmed by DSC and TGA analysis. These physical properties of films are comparable to that of polycarbonate which is widely used as optical film. Besides of these, mechanical and fracture properties of them were found to be also suitable for this purpose. Furthermore, negative birefringence could be obtained by orientationally stretching them. Such results indicate that, films prepared from composites are competent for negative birefringence optical compensator in the field of liquid crystal display. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011