甲基丙烯酸缩水甘油酯对大豆蛋白塑料改性作用研究

用模压的方法制备了甲基丙烯酸缩水甘油酯(GMA)改性大豆分离蛋白质(SPI)塑料。表征了GMA改性SPI塑料的力学性能、耐水性,并分析了GMA与SPI之间的相互作用。结果表明GMA在模压过程中,环氧基与蛋白质分子间发生接枝和交联反应,同时自聚,在GMA含量较低时可以同时对SPI塑料起到增强和增塑作用,但是随着GMA含量增加,交联作用增强,塑料的断裂伸长率下降。     

AMPS对PEO/PMMA固态聚合物电解质电导率的影响

针对固态聚合物电解质室温电导率较低的问题,采用刮膜法制备了PEO/PMMA/LiClO_4/AM PS共混聚合物电解质,考察了2-丙烯酰胺-2-甲基丙磺酸(AM PS)的端基磺酸基团对电解质性能的影响.结果表明,添加AMPS后,红外图谱中出现了由C—O的拉伸振动和SO_3~(2-)的络合作用所引起的尖峰.PMMA与PEO共混后,大大降低了PEO的结晶度,且添加AMPS后,电解质形成了完全均相体系.AMPS的添加使得电解质的电导率明显提升了两个数量级.当AMPS的质量分数为1.3%时,电解质的室温电导率达到最大值.添加同样含有端基磺酸基团的液晶离聚物(LCI)后,电解质的电导率无明显提升,因而可以选择磺酸基团质量比更高的AMPS作为添加剂.     

聚合松香HEMA酯化物与苯乙烯的共聚研究

以聚合松香(PR)与甲基丙烯酸-β-羟乙酯(HEMA)的酯化物(PRH)为单体,采用自由基溶液聚合方法制备了PRH与苯乙烯(St)的共聚物(PRHS)。探讨了单体比例、反应温度、引发剂用量和反应时间对共聚反应的影响。用红外光谱、热重分析和差示扫描量热分析对产物的结构、热稳定性和玻璃化转变温度进行了测试表征。结果表明:成功合成了酯化物PRH与St的共聚物PRHS;共聚物的热稳定性高于酯化物,苯乙烯用量越多,共聚物热稳定性和玻璃化转变温度越高;PRH与St共聚较佳的反应条件为:mPRH∶mSt=1∶2;反应温度为110℃;m(引发剂)∶m(单体)=1%;反应时间为8 h,在此条件下,产率达70.14%。     

Effect of tacticity of poly(methyl methacrylate) on interfacial region with silica in polymer nanocomposite

The effect of tacticity on the interfacial region between poly(methyl methacrylate) (PMMA) and silica in a PMMA/silica nanocomposite was investigated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The glass transition temperature (T_g) values of the syndiotactic (st-) and atactic (at-) PMMA/silica nanocomposites are higher than those of the neat PMMA. Conversely, the T_g of the isotactic (it-) PMMA/silica nanocomposite is slightly higher than that of the neat it-PMMA. DSC and XRD results suggest that the restriction of the PMMA chain mobility in the silica nanoparticle interfacial region heightens as the syndiotactic content increases. FT-IR results show that this phenomenon is caused by the interaction between the carbonyl group of PMMA and the silanol group on the silicon dioxide surface. Therefore, it can be concluded that the syndiotactic-rich PMMA has a significantly different molecular mobility from that of the neat PMMA in the interfacial region with silica nanoparticle surface than isotactic-rich PMMA.     

聚酯型双键封端聚氨酯预聚物的合成及其在团状模塑料中的应用

以高附着力耐温二元醇（XC-488）、甲苯二异氰酸酯（TDI）、甲基丙烯酸羟乙酯（HEMA）为原料,合成了聚酯型双键封端的聚氨酯预聚物（HPU）,然后将不同含量的HPU与不饱和聚酯树脂、短切玻璃纤维、碳酸钙、阻燃剂等进行共混,用于团状模塑料（BMC）的制备。通过傅里叶变换红外光谱、差示扫描量热仪、力学性能、吸水率、熔体流动性、耐酸碱性、耐老化测试和扫描电子显微镜进行测试。结果表明,当HPU的含量为6 %（质量分数,下同）时,BMC复合材料的综合力学性能最好,此时复合材料的拉伸强度、弯曲强度、冲击强度分别为（47.24 ±0.42） MPa、（117.76±0.65）MPa、（33.8±0.2） kJ/m²。     

Thermal degradation of foamed polymethyl methacrylate in the expendable pattern casting process

The thermal degradation of foamed polymethyl methacrylate (PMMA) patterns in the expendable pat-tern casting process has been studied. Various physical transitions that may occur during the degradation of PMMA have been determined using scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, and the effects of polymer density on the degradation characteristics have been investigated. The results indicate that, when exposed to elevated temperatures, the polymer beads collapse at about 140 to 200 °. The collapsed beads melt at 260 ° and begin to volatilize. Peak volatilization temperatures are on the order of 370 °. The end temperature for volatilization is between 420 and 430 °. The initial density of the polymer does not have a significant effect on the transition tem-peratures associated with degradation.     

Ultrastructural investigation of intact orbital implant surfaces using atomic force microscopy

This study examined the surface nanostructures of three orbital implants: nonporous poly(methyl methacrylate) (PMMA), porous aluminum oxide and porous polyethylene. The morphological characteristics of the orbital implants surfaces were observed by atomic force microscopy (AFM). The AFM topography, phase shift and deflection images of the intact implant samples were obtained. The surface of the nonporous PMMA implant showed severe scratches and debris. The surface of the aluminum oxide implant showed a porous structure with varying densities and sizes. The PMMA implant showed nodule nanostructures, 215.56 ± 52.34 nm in size, and the aluminum oxide implant showed crystal structures, 730.22 ± 341.02 nm in size. The nonporous PMMA implant showed the lowest roughness compared with other implant biomaterials, followed by the porous aluminum oxide implant. The porous polyethylene implant showed the highest roughness and severe surface irregularities. Overall, the surface roughness of orbital implants might be associated with the rate of complications and cell adhesion. SCANNING 33: 211–221, 2011. © 2011 Wiley Periodicals, Inc.     

PolyHIPE块体中甲基丙烯酸甲酯的ATRP溶液聚合

将用高内相比乳液(HIPE)聚合法得到的多孔聚合物块体(poly HIPE)作为聚合的反应器,在其内部进行甲基丙烯酸甲酯(MMA)的原子转移自由基聚合反应(ATRP),通过扫描电镜、凝胶渗透色谱、红外光谱、热重分析、核磁共振和差示扫描量热等测试手段对块体内聚合的PMMA进行了分析测试。研究表明,MMA在poly HIPE块体内部按照ATRP聚合机理发生聚合;poly HIPE块体对MMA的ATRP溶液聚合影响不同于受限空间内部进行的传统自由基聚合及反向原子转移自由基聚合(RATRP);相较于普通的ATRP溶液聚合,块体内部ATRP聚合所得PMMA的数均相对分子质量有所降低,相对分子质量分布变窄,热稳定性有所提高,间同立构比例有所下降,但全同立构比例明显增加,玻璃化转变温度有所下降。     

聚甲基丙烯酸甲酯/二氧化硅复合材料的热性能

聚甲基丙烯酸甲酯/二氧化硅(PMMA/Si O_2)复合材料可以通过简便的单体浇铸、本体聚合方法制备,二氧化硅用硅烷偶联剂3-(异丁烯酰氧)丙基三甲氧基硅烷(γ-MPS)进行表面修饰,并用红外光谱表征其甲苯抽提后的组成。当加入量为11.76%时,PMMA/Si O_2复合材料的导热率达到0.23 W/(m·K),比基体PMMA提高了27.78%。用PMMA红外光谱的侧甲基弯曲振动峰(δCH3)与羰基(νC=O)的伸缩振动峰比值可以表示PMMA大分子的偶合终止与歧化终止的比例,随着二氧化硅含量的增加,歧化终止比例升高,从而使PMMA/Si O_2复合材料的热稳定性提高,与热重分析结果一致。     

两亲性PP-g-(NVP-co-PEGMA)抗污染改性剂的制备及改性聚丙烯亲水微孔膜的表征

以乙烯基吡咯烷酮(NVP)和聚乙二醇甲基丙烯酸酯(PEGMA)为共聚单体,采用熔融接枝法制备了两亲性改性剂PP-g-(NVP-co-PEGMA);利用红外光谱、X射线光电子能谱对制得的改性剂进行表征,研究了PEGMA单体用量对熔融接枝聚合PVP接枝率的影响。利用熔融共混和拉伸成孔工艺制备了聚丙烯亲水微孔膜。利用接触角、热失重分析、扫描电镜和水通量测试对改性剂及膜性能进行表征。结果表明,亲水性支链成功接枝到PP大分子链上,少量PEGMA的加入提高了NVP的接枝率,相比NVP作为唯一单体的情况提高了5.66%;改性PP微孔膜的热稳定性能提高,亲水性也得到很大改善,起始接触角从96.0°下降到57.5°。膜的平均孔径在0.15μm左右,孔径分布相对均匀,孔隙率为32.7%。改性后的PP膜水通量随时间的延长下降缓慢,亲水性和抗污染性能得到大幅度提高。