胺基化反应增容PC/ABS共混物

采用熔融共混方法制备了ABS树脂接枝马来酸酐接枝共聚物(ABS-g-MAH),将接枝共聚物与1-(2氨乙基)哌嗪反应制备了增容剂,通过红外光谱表征确定了预期反应的发生.将增容剂部分替代聚碳酸酯(PC)/ABS共混物中的ABS树脂,考察了增容剂对PC/ABS共混物的力学性能的影响.结果表明,加入增容剂后,PC/ABS共混...     

增容剂对聚对苯二甲酸丁二酯/聚丙烯共混体系相形态、热稳定性与流变性能影响研究

为了丰富聚对苯二甲酸丁二酯(PBT)纤维品种,以乙烯-醋酸乙烯共聚物接枝马来酸酐(EVA-gMAH)、乙烯-辛烯共聚物接枝甲基丙烯酸缩水甘油酯(POE-g-GMA)和乙烯-丙烯酸酯-甲基丙烯酸缩水甘油酯(EMG)为增容剂,采用熔融共混法制备了不同组成比例的PBT/PP共混物,通过扫描电镜、差示扫描量热法、热失重分析法和毛细管流变仪等手段测试了共混物,考察增容剂种类和用量对共混物结构性能的影响。结果表明:共混物PBT/PP为不相容体系,选择共混物PBT/PP为70/30(质量比)时加入3种增容剂,发现增容剂对PBT/PP共混的增容效果为:EMGPOE-g-GMAEVA-g-MAH。共混物的熔点无明显变化,分解温度增加,耐热性增强。对比不同种类增容剂含量为1份的共混物,其表观黏度均随着剪切速率的增大而减小,说明改性共混物是假塑性流体。     

不同增容剂对POE增韧聚乳酸性能的影响

用双螺杆挤出机制备了聚乳酸(PLA)、聚烯烃弹性体(POE)和4种不同增容剂(马来酸酐接枝POE、马来酸酐、丙烯酸酯双官能化POE、丙烯酸酯与缩水甘油酯双官能化的POE、甲基丙烯酸缩水甘油酯接枝POE)的共混物,考察了不同增容剂对共混物力学性能和断面形貌的影响,分析了退火前后共混物力学性能的变化。结果表明,在使用自制的甲基丙烯酸缩水甘油酯接枝POE(POE-g-GMA)作为增容剂,三元体系PLA/POE/POE-g-GMA的质量比为80/15/5时,复合材料力学性能达到最佳,此时缺口冲击强度为12.3 kJ/m2,是纯PLA的3.7倍,拉伸强度为47.5 MPa。     

TPU与HDPE共混体系的γ-辐照增容

以乙烯醋酸乙烯共聚物接枝马来酸酐(EVA-g-MAH)做增容剂,采用双螺杆挤出机熔融共混法制备了热塑性聚氨酯(TPU)与高密度聚乙烯(HDPE)的共混物.研究了真空和空气中γ辐照对共混物力学性能的影响,结果表明适当剂量的辐照改善了TPU/EVA-g-MAH/HDPE的力学性能.     

聚乳酸固相接枝马来酸酐及与淀粉共混研究

通过固相接枝的方法,合成了聚乳酸与马来酸酐的接枝共聚物PLA-g-MAH,以改善其与淀粉共混物的相容性.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熔融共混物的力学性能和热性能.结果表明,在惰性气体环境中,聚乳酸可以和马来酸酐通过过氧化物引发而发生固相接枝反应.固定PLA100份,MAH 5份(质量比)不变,较好的工艺条件是引发剂用量为0.6份,120℃温度下反应1.4～1.6h.接枝聚乳酸与淀粉熔融共混,改善了聚乳酸和淀粉的相容性,提高了共混物的力学性能.     

CPE/P(AA-AM)吸水膨胀弹性体的研究

采用机械共混将氯化聚乙烯（CPE）与自制的吸水树脂丙烯酸－丙烯酰胺共聚物（P（AA－AM）共混，并且以合成的两亲聚合物为共混试样的增容剂实施增容，讨论了吸水树脂以及增容剂对共混试样的力党性溶胀性能的影响，结果表明简单共混时随吸水树脂量增大，共混试样的拉伸强度降低，其吸水率增大，CPE－g-PEG的加入改善了试样的力学性能，接技物的量为6份时，拉伸强度最大，添加不同量的接枝物，试样的平衡吸水率均增大，接枝物的加入，改善了共混试样的重复使用情况，降低了其质量损失率。     

熔融挤出HDPE/EVOH共混物的微观结构及性能

采用高密度聚乙烯(HDPE)接枝马来酸酐(MAH)或甲基丙烯酸缩水甘油酯(GMA)作为增容剂,熔融挤出制备HDPE/乙烯-乙烯醇共聚物(EVOH)共混物.通过扫描电镜观察、气体渗透试验以及力学性能试验,分析增容剂对共混物相容性的影响,并研究共混物的力学性能和阻隔性.结果表明:增容剂能显著提高共混物的相容性.与HDPE相...     

PA6/MBS/PP反应共混体系的相形态和力学性能

通过扫描电镜、热分析、熔体流动速率和力学性能等测试方法研究了马来酸酐(MAH)和苯乙烯(St)多单体熔融接枝VERSIFY2300(V-2300-g-(MAH-co-St))对PA6/MBS/PP共混物的结晶行为、相形态和力学性能的影响。结果表明,在熔融共混过程中,V-2300-g-(MAH-co-St)中的酸酐基团与PA6的端氨基原位生成的接枝共聚物有效降低了共混物的界面张力,接枝物中苯乙烯基团与甲基丙烯酸甲酯(M)-丁二烯(B)-苯乙烯(S)三元共聚物(MBS)作用,有助于提高共混物的相容性。当PA6/MBS/PP共混物加入V-2300-g-(MAH-co-St)质量分数为20%时,共混物分散相的尺寸明显减小,力学性能得到较大提高。     

PBA-g-PS对ACR/PS共混体系性能的影响

采用大单体技术合成聚苯乙烯和丙烯酸丁酯的规整接枝共聚物PBA-g-PS.研究了共聚合反应条件:聚苯乙烯大单体的投料质量分数,引发剂用量,反应温度对接枝效率的影响;PBA-g-PS可以作为ACR/PS体系的共混增容剂,研究共混物的组成,接枝物的用量,接枝物的组成对共混物物理机械性能的影响.用SEM,DSC表征共混物的变化,结果表明,接枝共聚物确实能促进两组分相容,起到增容剂的作用.     

聚丙烯酸丁酯接枝共聚物的可控合成及作为相容剂的应用

结合电子转移再生催化剂原子转移自由基聚合(ARGET ATRP)和普通自由基聚合,制备了一系列聚丙烯酸丁酯接枝共聚物,详细研究了其作为苯乙烯-丙烯腈共聚物树脂/丙烯酸酯橡胶(SAN/ACM)共混体系的相容剂,在制备丙烯腈-苯乙烯-丙烯酸酯树脂(ASA树脂)时,不同主链结构、侧链相对分子质量、接枝密度及用量对增容效果的影响。通过傅里叶变换红外光谱仪和凝胶渗透色谱仪对聚合物结构进行测试和表征;采用动态力学分析仪(DMA)和冲击试验机研究了共混物的力学性能。结果表明,成功制备了不同结构的聚丙烯酸丁酯接枝共聚物,以苯乙烯-丙烯腈共聚物(SAN)作为主链比聚丙烯酸丁酯(PBA)作为主链的接枝共聚物具有更好的增容效果。此外,侧链PBA的相对分子质量较小时,侧链与主链摩尔比为3∶1及相容剂用量为3%(质量分数)时,接枝共聚物的增容效果最佳。DMA分析表明添加接枝共聚物后SAN和ACM两组分的玻璃化转变温度相互靠近,聚丙烯酸丁酯接枝共聚物起到了明显的增容作用。     

不同核结构复合胶乳的制备及压敏特性

采用半连续乳液聚合法制备了三种不同核结构的复合乳液:P(BA-co-AA)、PMMA/P(BA-co-AA)和MPS-SiO2/P(BA-co-AA)复合胶乳,乳液聚合反应转化率高,乳胶粒最终粒径控制得基本相同.将此三种乳液涂布在PET薄膜上,测定了核结构对压敏胶粘接性能(如初粘、180°剥离和耐剪切等)的影响.热失重分析、动态机械热分析表征了热性能和动态力学性能.结果表明,丙烯酸酯聚合物中加入纳米二氧化硅有助于改善其耐热性能,而压敏胶的耐剪切性能显著提高.     

Mechanical and Barrier Properties of LLDPE/Chitosan Blown Films for Packaging

The blends of linear low‐density polyethylene and chitosan were prepared by using a two‐step melt‐compounding process and then were made into blown films for packaging. LLDPE‐g‐MAH was used as compatilizer to enhance the dispersing effect of chitosan in the matrix. Fourier transform infrared spectra and scanning electron microscope images of the blown films confirmed that there were new amide bonds formed between chitosan and LLDPE‐g‐MAH. The mechanical and barrier properties of the LLDPE/chitosan blown films were investigated. The result indicated that the breaking strength and elongation decreased as the chitosan content increased. In addition, the water vapour permeability of the blend films could be improved up to 200% with the increment of chitosan content, and the oxygen permeability decreased about 20% compared with the films without chitosan. It was found that LLDPE‐g‐MAH had obvious effects on the mechanical properties and oxygen permeability apart from the water vapour resistance. Copyright © 2015 John Wiley & Sons, Ltd.     

PP镁盐晶须复合材料的性能研究

研究了镁盐晶须填充改性聚丙烯(PP)材料的力学性能以及PP-g-MAH和PP-g-GMA为相容剂对复合材料的影响等.结果表明:镁盐晶须能明显改善PP材料的拉伸强度、弯曲强度和弯曲模量等力学性能;PP-g-MAH和PP-g-GMA作为相容剂改善镁盐晶须对PP的增韧补强作用.     

酰胺链硅烷界面结合剂对尼龙66/玻纤复合材料性能的影响

采用熔融挤出共混制备了尼龙66(PA66)/玻璃纤维(GF)复合材料,比较了常用硅烷偶联剂KH550与不同有机酸封端的酰胺链硅烷界面结合剂(ASI)对复合材料的力学性能、动态力学性能及界面层结构的影响,探究了复合材料中界面层形成的机理。结果表明,ASI与玻纤表面反应发生了化学反应,ASI添加量为1.5%时,对PA66/GF复合材料的力学性能改善效果最明显,其中,以对苯二甲酸封端,相对分子质量为2000左右的PTA-ASI使PA66/GF复合材料的界面能力提升最高,拉伸强度提高了54.8%,复合材料的综合性能提高最为显著。     

Microstructure-mechanical properties relationship in conducting polypyrrole films

In this paper, the microstructures of electrochemically synthesized conducting polypyrrole (PPy) films were studied by scanning electron microscopy (SEM). It was found that the polymer film growth condition has strong effects on mechanical properties of the polymer film. The relationship between mechanical properties (such as tensile strength and brittle—tough properties) and the microstructures of PPy films was described for the first time. The effect of electrochemical polymerization condition including temperature and electrolyte composition on the strength and brittle—tough properties was also studied. Films deposited both on the surface of the anode facing the counter electrode and on the back surface were characterized. In order to improve the mechanical properties of PPy films, an optimal condition of electrochemical synthesis of conducting PPy films has been recommended.     

细乳液法制备有机硅氧烷改性苯丙乳液

采用细乳液法制备γ-甲基丙烯酰氧基正丙基三甲氧基硅烷(MPS)改性苯丙乳液。研究了引发剂、pH值、MPS的用量等对乳胶膜凝胶含量、溶胀比及动态力学性能的影响。溶胀实验表明,乳胶粒子和乳胶膜凝胶含量及溶胀比主要受体系的pH值影响比较大。动态力学分析表明,在中性条件下使用过硫酸钾(KPS)引发剂得到的乳胶膜的储存模量要高于偶氮二异丁腈(AIBN)乳胶膜的储存模量;增加MPS的用量以及对乳胶膜进行酸化处理或热处理可以提高乳胶膜的储存模量。     

Mechanical characterization and drug permeation properties of tetracaine-loaded bioadhesive films for percutaneous local anesthesia

In the development of bioadhesive patch devices for percutaneous local anesthesia, the tensile properties of the films produced after the casting of the gel intermediates is of key importance to the clinical compliance of the product, and its effective delivery of the local anesthetic agent. A range of bioadhesive patches were formulated and their mechanical and in vitro permeation properties determined. Altering formulation significantly altered the mechanical properties of films. The tensile properties of the films could be modified to allow concomitant benefits in the mechanical and drug permeation properties of the films, ensuring that patches not only exerted clinically beneficial effects, but are also mechanically robust. Tetracaine was found to plasticize films and while this effect was weak, it was significant both statistically and potentially also in the effect it has on the clinical use of these devices. Drug release from tetracaine patches demonstrate the same trends as found previously across polydimethylsiloxane films. By altering the formulation of the patch device, the drug release from the device to the skin is readily and accurately controlled, and was not solely a function of the stratum corneum barrier properties but additionally of the formulation.     

Microtensile tests of mechanical properties of nanoporous Au thin films

The mechanical properties of nanoporous Au (NPG) thin films were investigated by uniaxial microtensile tests. Such mechanical parameters as Young’s modulus, tensile strength, and breaking strain were obtained from the recorded force–displacement curves. Through observations on the microstructure and fracture surface morphology of the samples after the tension tests by a scanning electronic microscope (SEM) and an optical microscope, we analyzed the physical mechanisms underlying the mechanical behavior of NPG thin films. It was found that the NPG films exhibit mechanical properties distinctly different from its bulk counterpart.     

Mechanical Characterization and Drug Permeation Properties of Tetracaine-loaded Bioadhesive Films for Percutaneous Local Anesthesia

ABSTRACT

In the development of bioadhesive patch devices for percutaneous local anesthesia, the tensile properties of the films produced after the casting of the gel intermediates is of key importance to the clinical compliance of the product, and its effective delivery of the local anesthetic agent. A range of bioadhesive patches were formulated and their mechanical and in vitro permeation properties determined. Altering formulation significantly altered the mechanical properties of films. The tensile properties of the films could be modified to allow concomitant benefits in the mechanical and drug permeation properties of the films, ensuring that patches not only exerted clinically beneficial effects, but are also mechanically robust. Tetracaine was found to plasticize films and while this effect was weak, it was significant both statistically and potentially also in the effect it has on the clinical use of these devices. Drug release from tetracaine patches demonstrate the same trends as found previously across polydimethylsiloxane films. By altering the formulation of the patch device, the drug release from the device to the skin is readily and accurately controlled, and was not solely a function of the stratum corneum barrier properties but additionally of the formulation.