聚甲基乙撑碳酸酯/氯化聚乙烯共混材料的制备与性能

通过熔融共混制备了不同比例的聚甲基乙撑碳酸酯/氯化聚乙烯共混材料(PPC/CPE),通过红外光谱分析仪(FTIR)、扫描电子显微镜(SEM)、热重分析仪(TG)、万能测试机、以及动态热机械分析(DMA)分别研究了共混材料的微观结构、相容性、热稳定性以及力学性能。结果表明:CPE和PPC具有良好的相容性;CPE能够有效增韧PPC,20%CPE添加量的共混材料断裂伸长率达到556%,冲击强度是纯PPC的140%,且拉伸强度还能保持17.5 MPa。     

聚碳酸亚丙酯和聚氨酯弹性体复合材料制备及其性能的研究

本实验采用熔融共混的方式制备了聚碳酸亚丙酯(PPC)/聚氨酯弹性体(TPU)复合材料。通过红外光谱分析(FT-IR)、微机控制电子万能试验机、悬臂梁冲击试验机、差示量热扫描分析仪(DSC)、热重分析仪(TG)、扫描电子显微镜(SEM)、熔体质量流动速率仪、转矩流变仪对共混物的微观形态、相容性、热稳定性、力学性能等进行了研究。结果表明:共混体系中材料的相容性较好,聚氨酯弹性体的引入提高了复合材料的热稳定性和力学性能,当聚氨酯弹性体的质量分数为40%时,共混物的拉伸强度达到23.5 MPa,提高了约13 MPa;5%分解温度Tb5为353.3℃,较PPC提高了104.6℃。     

马来酸酐接枝聚乳酸增容聚碳酸亚丙酯/聚乳酸共混体系的结构与性能研究

采用熔融接枝技术将马来酸酐(MAH)接枝到聚乳酸(PLA)上,制备不同MAH含量的PLA-g-MAH接枝共聚物,将聚碳酸亚丙酯(PPC)、PLA、PLA-g-MAH熔融共混,制备PPC/PLA/PLA-g-MAH共混物,分析接枝物中MAH含量对PPC/PLA/PLA-g-MAH共混体系的热学性能以及力学性能的影响。结果表明:PLA-g-MAH可以改善PPC与PLA二者的相容性,使PLA在降温过程中更容易结晶。引入接枝物后,共混物的起始分解温度及完全分解温度分别提高30℃和60℃。共混物的力学性能随着接枝物中MAH含量的增加呈现先增加后减小的趋势,当MAH的加入量为3%,共混体系力学性能最佳,冲击断面塑性形变程度更加显著,呈现褶皱状韧性断裂特征,拉伸强度达到42.8 MPa,断裂伸长率为120%左右,同时冲击强度最大。     

完全生物降解塑料PLA/PPC合金的结构与性能研究

利用机械共混法,将聚乳酸(PLA)与聚丙撑碳酸亚丙酯(PPC)熔融共混,制备了完全生物降解塑料PLA/PPC合金,并用FTIR、流变仪等手段研究了其结构、力学性能和流变性能。结果表明该共混体系具有良好的相容性、力学性能和熔体流动性,PLA与PPC之间存在着较强的相互作用,PPC的加入使体系拉伸强度下降幅度不大,断裂伸长率升高到23.8%,比纯PLA提高近20倍。共混体系的黏度亦随着PPC的加入逐渐增大,PLA/PPC(50/50)体系的黏流活化能为37.1kJ/mol,同时在一定的温度范围内,提高切应力也会使体系黏度下降。     

聚碳酸亚丙酯/聚乙烯醇共混复合材料的性能

采用熔融共混挤出的方式制备了可生物降解的聚碳酸亚丙酯(PPC)/聚乙烯醇(PVA)复合材料。运用差示扫描量热仪(DSC)、热失重分析仪(TGA)、扫描电子显微镜(SEM)和万能试验机分别研究了复合材料的相容性、热稳定性、微观形态以及力学性能。结果表明:复合体系中材料的相容性较好,改性PVA的引入提高了复合材料的热稳定性和拉伸强度,当改性PVA的质量分数为50%时,拉伸强度达到39.2 MPa,提高了约177%。     

加料顺序对PLA/PBS/PEG共混物的力学性能及耐热性影响

通过熔融开炼共混法制备了聚乳酸(PLA)/聚丁二酸丁二酯(PBS)/聚乙二醇(PEG)共混物,考察了不同加料顺序对共混物的影响。利用电子拉力试验机测试共混物的力学性能,同步热分析仪分析其热稳定性。实验证明,PLA和PBS熔融混合均匀后,再加入PEG的加料顺序,可以提高PLA/PBS/PEG共混物的韧性;PEG加入可以提高共混物的热稳定性。通过扫描电子显微镜、X射线衍射仪、偏光显微镜进一步证明,PLA和PBS熔融混合均匀后,再加入PEG的加料顺序,可以更有效地均化分散相尺寸,细化结晶粒度,降低体系的界面张力,提高两相的相容性。     

MCC对PLA/PPC复合材料力学性能与热稳定性的影响

以微晶纤维素(MCC)作为改性剂,马来酸酐接枝聚乳酸(PLA g MAH)为界面相容剂,聚乳酸(PLA)、聚碳酸亚丙酯(PPC)为基体,通过熔融共混法制得PLA/PPC/MCC三元复合材料。采用控温拉伸、动态热分析、扫描电子显微镜以及热失重分析等方法研究了MCC对PLA/PPC的力学性能和热稳定性。结果表明,PLA/PPC/MCC三元复合材料的拉伸强度提高了12.7 %,玻璃化转变温度（Tg）提高了9.8 ℃;PLA g MAH的加入可以改善PLA/PPC/MCC三元复合材料的界面性质,从而提高力学性能和热稳定性;当PLA g MAH的添加量为5 %（质量分数,下同）时,三元复合材料在常温下的拉伸强度、弯曲强度和冲击强度分别提高了53.7 %、43.1 %和18.5 %;在60 ℃下三元复合材料的断裂强度提高了80 %;热降解温度以及最大失重温度与PLA/PPC相比分别提高了25.31 ℃和61.83 ℃。     

聚丁二酸丁二醇酯与聚乳酸共混型全生物降解材料的结构和性能研究

通过机械共混法,使聚丁二酸丁二醇酯(PBS)、聚乳酸(PLA)熔融共混,制备了一种完全生物降解塑料。用红外光谱(FTIR)法、DSC(DifferentialScanningCalorimetry)法、扫描电镜法(SEM)及力学测试等手段研究了不同组分配比情况下共混物的结构、热性能以及力学性能变化。并研究了聚丙撑碳酸亚丙酯(PPC)的加入对共混体系性能的影响。结果表明:随着PBS含量的增加,PBS/PLA共混体系的拉伸强度降低不多,而断裂伸长率显著提高。而PPC的加入能够提高共混体系的相容性并显著提高体系的韧性。     

聚乳酸/聚乙醇酸共混合金界面改性研究

用熔融共混挤出法制备了不同配比的聚乳酸(PLA)/聚乙醇酸(PGA)共混合金,并分别加入环氧型扩链剂ADR 4370F进行对比分析,通过拉伸性能测试、弯曲性能测试、缺口冲击强度测试、扫描电子显微镜(SEM)和差示扫描量热(DSC)仪研究了共混合金力学性能、相容性和结晶性能。结果表明:与纯PLA和纯PGA相比,PLA/PGA共混合金的相容性差,导致力学性能降低,纯PLA、纯PGA和70%PLA/30%PGA合金的拉伸强度、弯曲强度、断裂伸长率和缺口冲击强度分别为58.6 MPa,123.5 MPa,8.52%,9.0 J/m;91.9 MPa,157.6 MPa,7.9%,5.2 J/m;41.2 MPa,91.2 MPa,3.8%,2.0 J/m。PLA和PGA可以互相加快结晶速度,加入环氧型扩链剂可以改善合金的相容性,上述四个力学性能可相应提高到49.2 MPa,96.0 MPa,4.5%,4.3 J/m,而且降低了PLA和PGA的结晶度。另外,向PLA中加入1%PGA时,PGA可以充当PLA的成核剂,使PLA的冷结晶温度降低10℃左右,结晶度提高1.3%。     

胺端基型超支化乙二胺三嗪聚合物对PLA/PPC的增韧改性研究

以乙二胺和三聚氯氰作为原料,以丙酮为溶剂,通过“一步法”合成了胺端基型的超支化乙二胺三嗪聚合物(HBETP)。以HBETP作为改性剂,采用双螺杆挤出机熔融共混和注射成型法制备了聚乳酸(PLA)/聚碳酸亚丙酯(PPC)共混物,并用差示扫描量热仪(DSC)、 热失重分析仪(TGA)、电子万能试验机、扫描电字显微镜(SEM)等测试手段对共混物的热性能、力学性能以及断面形貌等进行表征与测试。结果表明,与PLA/PPC共混物相比,当HBETP含量为0.6份时,PLA/PPC/HBETP共混体系在保持拉伸强度基本不变的基础上,断裂伸长率和冲击强度分别提高了266.0 %和122.9 %;HBETP是一种增韧PLA/PPC共混物的有效助剂。     

PES/PA6的共混纺丝及其性能研究

将不同质量比的聚醚砜(PES)与聚酰胺6(PA6)共混进行熔融纺丝制得PES/PA6共混纤维;研究了共混物的流动性及其纺丝工艺,以及PES/PA6共混纤维的热稳定性和力学性能。结果表明:PA6的加入显著提高了PES的流动性,降低了纺丝温度,改善了PES的可纺性;与纯PES纤维相比,PES/PA6共混纤维的起始热分解温度有所降低,PES/PA6质量比为70/30～30/70的PES/PA6共混物的纺丝温度为320～340℃,卷绕速度为100～400 m/min,纤维的断裂强度为0.71～2.25 cN/dtex。     

Biodegradable PPC/(PVA-TPU) ternary blend blown films with enhanced mechanical properties

Biodegradable films of poly(propylene carbonate)/poly(vinyl alcohol)-thermoplastic polyurethane [PPC/(PVA-TPU)] ternary blends were successfully prepared by melting blending method. The mechanical properties of poly(propylene carbonate) blown film were greatly improved by blending PPC with PVA-TPU. In order to afford the melt processing of PVA, the PVA-TPU binary blend was firstly prepared using thermoplastic polyurethane as a polymeric plasticizer. The rheological behavior, mechanical properties and morphology of these blends were studied. Considering its melt viscosity and thermally processing temperature, the PVA-50%TPU, as a modifier, was blended with PPC to prepare PPC/(PVA-TPU) ternary blend. SEM observation revealed a basic one-phase morphological structure with very good interfacial adhesion between the extremely blurred PPC and PVA-TPU two components. Meanwhile, the miscibility of the ternary components was verified by only one glass-transition temperature obtained from DMA tests. The tensile strength and tear strength of PPC/(PVA-TPU) blown films were determined at different temperatures. The results demonstrate that the mechanical properties of PPC/(PVA-TPU) films were enhanced dramatically at low temperature when compared with neat PPC. At room temperature, PPC/30 %(PVA-50%TPU) blown film exhibited a tensile strength of 26 MPa, and an elongation at break of 484.0 %. Its tear strength in the take-up direction is 124.1 kN/m, and the one in machine direction is 141.9 kN/m. At a low temperature of 0 °C, PPC/30 %(PVA-50%TPU) exhibited a tensile strength of 40.7 MPa and tear strength of 107 kN/m, which are 153 % and 142 % of those of neat PPC respectively. The blending of PPC with the PVA plasticized with TPU provides a practical way to extend the application of the new biodegradable polymer of PPC in the area of blown films.     

Effects of thermoplastic poly(ether-ester) elastomer and bentonite nanoclay on properties of poly(lactic acid)

This work presented the influence of thermoplastic poly(ether-ester) elastomer (TPEE) and bentonite (BTN) on improving the mechanical and thermal properties of poly(lactic acid) (PLA). PLA was initially melt mixed with TPEE at six different loadings (5–30 wt%) on a twin screw extruder and then injection molded. The mechanical tests revealed an increasing impact strength and elongation at break with increasing TPEE loading, but a diminishing Young's modulus and tensile strength with respect to pure PLA. The blend at 30 wt% TPEE provided the optimum improvement in toughness, exhibiting an increase in the impact strength and elongation at break by 3.21- and 10.62-fold over those of the pure PLA, respectively. Scanning electron microscopy analysis illustrated a ductile fractured surface of the blends with the small dispersed TPEE domains in PLA matrix, indicating their immiscibility. The 70/30 (wt/wt) PLA/TPEE blend was subsequently filled with three loadings of BTN (1, 3, and 5 parts by weight per hundred of blend resin [phr]), where the impact strength, Young's modulus, tensile strength and thermal stability of all the blends were improved, while the elongation at break was deteriorated. Among the three nanocomposites, that with 1 phr BTN formed exfoliated structure and so exhibited the highest impact strength, elongation at break, and tensile strength compared to the other intercalated nanocomposites. Moreover, the addition of BTN was found to increase the thermal stability of the neat PLA/TPEE blend due to the barrier properties and high thermal stability of BTN.     

Studies on the blends of CO2 copolymer. IV. Natural rubber/poly(propylene carbonate) systems

The blends of a carbon dioxide copolymer, poly(propylene carbonate)(PPC) with natural rubber (NR), were prepared and their mechanical properties and morphology were studied. The optimum formulation blend was obtained by orthogonal experiments. The tensile strength of the blend containing 30 phr PPC was 18.9 MPa, with an elongation at break of 755%. The factors such as PPC and dicumyl peroxide content, PPC molecular weight, sulfur content, curing time, and curing temperature responsible for controlling the mechanical properties were discussed. Transverse electron micrographs showed a two‐phase structure for this blend. Gel content data revealed that PPC was crosslinked. The phase stability of PPC in the blend improved because of the interpenetrating new work structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2140–2144, 2002     

可降解聚碳酸亚丙酯复合材料的性能

通过聚碳酸亚丙酯(PPC)与聚乳酸(PLA)的共混,提高PPC的热性能、力学性能、生物降解性。利用扫描电子显微镜(SEM)、多晶X衍射(XRD)、差示扫描量热(DSC)、热重分析(TG)、拉伸力学实验研究了复合材料的性能。实验结果表明,聚合物之间没有发生化学反应,共混物为部分相容的体系;复合材料的玻璃化转变温度最高比PPC提高30℃,分解温度Td5%最多比PPC提高42℃,Td50%最多比PPC提高67℃;PLA的加入使复合材料的降解性能优于PPC,40d降解后复合材料最大失重率为33.37%,是PPC的9倍;PPC-PLA复合材料有良好的成膜性,制备的薄膜透明均匀,复合薄膜材料拉伸强度为36～58MPa,杨氏模量最大为2943MPa。     

聚乳酸/聚酰胺弹性体/聚乙酸乙烯酯共混纤维的制备及性能研究

以聚乙酸乙烯酯(PVAc)为增容剂,采用熔融共混和熔融纺丝的方法制备了聚乳酸(PLA)/聚酰胺弹性体(PAE)/PVAc共混切片和共混纤维,研究了增容剂的加入对共混切片相容性的影响和共混纤维増韧改性效果的影响。结果表明,加入PVAc后,分散相粒子尺寸减小,两相界面模糊,相容性提高。随着PAE弹性体含量增加,初生纤维中PLA的结晶度提高;二级牵伸共混纤维在PAE含量为10%时,综合力学性能最优,断裂强度、模量、断裂伸长率和断裂功分别达412.7 MPa、6 345.4 MPa、22.3%和127.4 mJ,共混纤维的可纺性显著提高。     

热塑性淀粉/纤维共混物性能的研究

用甘油作为塑化剂，将糊化淀粉和溶胀纤维按不同配比进行熔融共混来制备完全可生物降解塑料。实验探讨了纤维质量分数对共混体系力学性能、耐水性及热性能的影响。扫描电镜显示了纤维较好地分散在热塑性淀粉(TPS)中，纤维和淀粉结合良好。纤维质量分数对共混体系力学性能影响的研究显示，纤维的加入可以明显地改善体系的力学性能。随着纤维质量分数由0提高到20％，共混体系的拉伸强度达到15．5MPa，杨氏模量达到81．4MPa；伸长率从104％降到7％。同时加入纤维后共混体系的耐水性明显提高。     

Effect of chain extrender on the compatibility,mechanical and gas barrier properties of poly(butylene adipate-co-terephthalate)/poly(propylene carbonate) bio-composites

Bio-composites consisting of poly(butylene adipate-co-terephthalate) (PBAT), poly(propylene carbonate) (PPC) and epoxy chain extender ADR 4468 were fabricated via melt blending using a torque rheometer. The relationship of the torque, melt viscosity, and molecular weight of the bio-composites was established via polymeric liquid theory to estimate the real-time chain extension reaction rate under different ADR contents. At the meantime, rheological behavior, thermal and mechanical properties, morphologies, gas barrier properties of the PBAT/PPC/ADR bio-composites were systematically characterized. The corresponding results revealed that the water vapor transmission rate (WVTR) reduced by 50% under 30 phr (parts per hundreds of resin) PPC content. The addition of ADR is beneficial to improve the mechanical properties, thermal stability and phase dispersion of PBAT/PPC without affecting the water barrier property. With 3 phr ADR, the tensile stress and elongation at break were increased from 19.5 MPa and 1184% to 26.9 MPa and 1443%, respectively. In addition, the data of the torque rheometer revealed that the chain extension reaction rate and the melt viscosity was increased with the increasing ADR content, but the reaction rate was reduced with the excessive viscosity.     

海藻酸钙/纳米TiO_2共混纤维的制备与表征

将含固体质量分数为5%的海藻酸钠纺丝原液与纳米二氧化钛(TiO2)水分散液均匀混合,制得海藻酸钠/纳米TiO2混合纺丝原液,采用湿法纺丝,通过氯化钙凝固浴,经拉伸、水洗,制备了海藻酸钙/纳米TiO2共混纤维,研究了纳米TiO2含量对共混纤维结构及性能的影响。结果表明:纳米TiO2的加入,提高了共混纤维的力学性能;加入质量分数为0.5%的纳米TiO2,海藻酸钙大分子链上的红外特征吸收峰峰形明显变宽,共混纤维的力学性能最佳,断裂强度为2.93 cN/dtex,断裂伸长率为7.34%,优于海藻酸钙纤维;添加纳米TiO2质量分数为3%时,纳米TiO2在共混纤维中仍能较好的分散,且纤维表面光滑。加入纳米TiO2后,共混纤维的热稳定性提高。