丙烯酸微波低温等离子体引发PET接枝改性的研究

用丙烯酸微波低温等离子体对聚酯膜进行接枝改性,并通过依次改变丙烯酸微波低温等离子体处理气体压力、功率和时间三因素优化出了处理聚酯膜的最佳工艺条件,并用此工艺条件对涤纶织物进行了水洗效果测试,同时用红外谱图和电镜照片进行了表征。研究表明,丙烯酸微波低温等离子体对聚酯膜有刻蚀作用,处理后可将丙烯酸接枝到聚酯膜上,证明将丙烯酸气体的微波低温等离子体直接作用于材料进行表面改性是可行的。     

低温等离子体在PET纤维接枝甲基丙烯酸中的应用研究

用辉光放电空气低温等离子体法处理涤纶长丝,液相接枝甲基丙烯酸(MAA),对纤维进行了改性.探讨了空气等离子体处理条件及接枝工艺条件对接枝率的影响.结果表明:空气低温等离子体引发最佳工艺条件为气压20 Pa、功率60 W、时间20 s;接枝最佳工艺条件:ψ(甲基丙烯酸)为15%(对溶液体积)、80℃反应1.5 h,接枝率可达2%左右.通过红外图谱和扫描电镜表征纤维表面接枝了甲基丙烯酸.     

低温等离子体处理对苎麻织物的深染性研究

本文采用等离子体表面处理、等离子体引发接枝聚合处理及化学整理与等离子体联合处理三种方式,对苎麻织物的氧等离子体改性及深染性进行了研究,系统探讨了等离子体放电时间、功率、真空度与苎麻织物失重率、吸湿性、上染率及深染性的关系.     

等离子体接枝丙烯酸PTT织物的染色性能

利用低温等离子体技术对PTT织物进行改性,在氧气存在下经等离子处理后接枝丙烯酸.通过对处理后试样进行染色性能测试,系统地研究了各处理方法所涉及的实验参数,如放电功率、放电时间、工作压强、接枝反应时间等对PTT织物染色效果的影响,通过Datacolor测色配色仪测定K/S值.研究结果表明:采用等离子体处理方法并进行接枝可以使试样表面引入极性基团,PTT织物的染色性明显改善,在放电功率70 W、丙烯酸浓度80％、工作压强30 Pa、处理时间7 min、反应时间6h的条件下,染色性能较好.     

半胱氨酸改性聚丙烯中空纤维膜的制备及表征

 采用紫外光接枝法在聚丙烯膜表面接枝甲基丙稀酸缩水甘油酯,再在碱性条件下,使环氧基与半胱氨酸发生开环反应,得到半胱氨酸改性聚丙烯膜PP-g-Cys。通过红外与X光电子能谱分析表明:改性膜表面新增了羧基、酯羰基、羟基等基团,且膜表面C元素含量下降,O元素含量增加,并出现S、Na元素。改性膜具有明显的两性荷电特征,接枝率为7.6%的改性膜等电点为7.2,而接枝率为16.1%的改性膜等电点为6.5。改性膜的电镜照片显示,随着接枝率的增加,膜表面微孔逐渐出现堵塞现象。改性膜的水通量随接枝率的增加而增加,但在较高的接枝率下,由于膜表面微孔大量堵塞,水通量下降。     

玄武岩长丝表面低温等离子体处理及其浆丝集束性能

针对玄武岩纤维表面光滑、集束性差且呈化学惰性,纤维浸润性差导致其与浆液黏附力不足的缺陷,采用低温等离子体技术改性玄武岩长丝表面,以改善玄武岩长丝浆丝时集束性能。探讨放电功率、放电气压及放电时间对玄武岩长丝表面形态、静摩擦因数、动摩擦因数及力学性能的影响,借助扫描电子显微镜对改性玄武岩长丝的表观形貌进行表征,分析改性玄武岩长丝与纺织浆料黏附性能的关系。结果表明：低温等离子体改性后玄武岩长丝表面粗糙程度提高,比表面积增大,摩擦因数增加,玄武岩长丝与纺织浆料的黏附性增强,集束性明显改善;当放电功率为300 W,放电气压为30 Pa,放电时间为7 min 时,改性玄武岩长丝上浆率高,浆丝集束性好。     

螺旋波等离子体发射光谱研究

为了解螺旋波等离子体的光学行为及特性,对螺旋波等离子体氩气放电进行了发射光谱(OES)测量,结果显示:谱线强度在模式转换时出现大幅增加。研究了不同气压下谱线强度随功率的变化关系,并采用发射光谱强度比值法对电子激发温度进行了计算,结果表明:在螺旋波放电阶段对应的电子激发温度随着功率增加呈下降趋势。     

羊绒纤维等离子体氧化-低温交联剂接枝改性

选用3种阳离子染料(阳离子红X-GRL、阳离子金黄X-GL、甲苯胺蓝)对氧气等离子体辐射羊绒进行染色，结合纤维强力变化，确定等离子体预处理最优工艺。通过2种低温交联剂(氮丙啶交联剂、聚碳化二亚胺)分别将丝胶蛋白接枝在等离子体处理后的羊绒上，并对等离子体接枝羊绒纤维接枝效果与保健功能进行综合性评价。结果发现，氧气低温等离子体最佳处理工艺为：功率200 W,放电时间240 s,进气量300 mL/min;氧气等离子体处理后羊绒纤维大分子引入了羧基，接枝中低温交联剂与羊绒大分子及丝胶蛋白发生了架桥反应，丝胶蛋白在羊绒纤维表面成功固定。氮丙啶交联剂的架桥效果要优于聚碳化二亚胺，二者的最大接枝率分别为6.30%与5.89%。同时，丝胶蛋白-氮丙啶交联剂-等离子体改性羊绒能够赋予纤维抗氧化功能(抗氧化率50.18%)和抗菌功能(金黄色葡萄球菌、大肠杆菌的抗菌率分别为80.42%、77.54%)。     

PE/PP非织造布的次辉光放电接枝改性

采用常压次辉光等离子体对PE/PP非织造布进行预处理,然后与甲基丙烯酸接枝聚合改性.分析了等离子体处理时间,接枝反应时单体浓度、时间、温度、还原剂浓度等对接枝率的影响.结果表明,接枝后非织造布的润湿性能、染色性能和抗静电性能较未处理和仅用等离子体改性处理的织物有明显改善.     

真丝织物等离子体接枝聚合改性

把等离子体接枝共聚方法应用于真丝织物的改性研究了丙烯酰胺、丙烯酸接枝聚合条件对接枝率、抗皱性、染色性及力学性能的影响。实验结果表明，等离子体接枝聚合可在不影响真丝织物原有力学性能、光泽、手感的情况下，在１％左右丙烯酰胺接枝率时，使折皱回复角提高２０－３０％；在丙烯酸接枝时，可提高对阳离子染料的上染能力及色牢度。     

Effect of dual modification of banana starch and storage time on thermal and crystallinity characteristics of its films

Banana starch was oxidized at three different levels and subsequently acetylated. This double modified banana starch was used for film preparation with the addition of glycerol. Thermal and crystallinity properties were evaluated. Acetylation decreased the peak temperature and enthalpy of double modified banana starch. When the oxidation level and storage time increased in films elaborated with the double modified banana starch, both thermal parameters increased as well. The T_g showed slight changes in films prepared with the double modified banana starch compared to its oxidized counterpart, and similar patterns were found when oxidation levels increased in double modified films. However, a decrease in the T_g was determined with the storage time in films prepared with oxidized and double modified starches. Films prepared with the double modified banana starch presented lower percentage of crystallinity than its oxidized counterpart, nevertheless at higher storage periods, crystallinity levels increased. Thermal and crystallinity properties of films prepared with double modified banana starch could be used to understand the behavior during their application.     

低温氩等离子体表面改性提高PET亲水性

为了提高PET材料表面的亲水性,应用低温氩等离子体对PET进行表面处理。对不同等离子体处理工作参数(放电功率、放电时间、工作气压)下PET薄膜表面的水接触角变化进行了规律性和原理分析。用IR和SEM分析了处理前后PET薄膜表面形态的变化。实验结果表明:不同等离子体处理工作参数下PET薄膜表面的水接触角的变化呈现不同的规律性;经等离子体处理后PET薄膜表面CO和CC键的数量增加,酯基数量减少,显著提高了薄膜的亲水性;但是低温氩等离子体处理后的PET薄膜放置一段时间后时效性问题比较明显。     

Improved solubility of banana starch by dielectric barrier discharge plasma treatment

A novel technology for banana starch modification has been developed using dielectric barrier discharge (DBD) plasma, and the effect of DBD plasma treatment on the solubility and pasting behaviours of banana starch were evaluated. The solubility of treated starch significantly increased from 1.35 to 15.05 g 100 g⁻¹ at 55 °C as the treatment intensity increased. Rapid viscosity analyser examination showed a dramatic change in the pasting behaviours of modified starch, and the peak viscosity decreased from 5242.0 to 153.0 (cP) as the treatment intensity increased. Evidence of nonpenetrative damage caused by plasma etching was shown by scanning electron microscope micrographs. The results of X-ray diffraction and Fourier-transform infrared spectroscopy analyses indicated that the DBD treatment changed the granular structure of banana starch.     

Synthesis of Starch Copolymers by Silicon Tetrachloride Plasma‐Induced Graft Polymerization

Corn starch was surface‐functionalized by 13.56 MHz RF SiCl₄‐plasma, in situ reacted with ethylenediamine for stabilization, and subsequently graft‐polymerized using dichlorodimethylsilane as monomer. SiCl₄‐plasma treatment was studied and discharge parameters were optimized. X‐ray photoelectron spectroscopy (XPS/ESCA), Fourier transformed infrared spectroscopy (FTIR), scanning electron spectroscopy (SEM), gas chromatography/mass spectroscopy (GC‐MS), and differential thermal analysis/thermal gravimetry (DTA/TG) proved the presence of a polydimethylsiloxane (PDMS) graft‐copolymer layer on the modified starch‐granule surfaces. These analyses show that the surface morphology of starch granules, the thermal properties, the swelling characteristic, and the hydrophilicity of starch were all changed due to the existence of a protective hydrophobic PDMS layer. It is suggested that the starch graft‐copolymer might find its applications as reinforcing component in silicone‐rubber materials for starch‐based composites.     

复合改性淀粉膜材料工艺优化与性能分析

本文研究了酶解脱支和醚化复合改性淀粉为基材制备了淀粉膜,在此基础上添加其他助剂逐渐提升淀粉膜材料的性能,利用现代分析仪器解析其结构特征并初步探讨相关机理。通过优化实验确定了淀粉膜材料工艺参数：复合改性淀粉材料浓度为3%,甘油含量为30%,料液温度为95 ℃,柠檬酸含量为10%时,制备的复合改性淀粉膜材料性能较好,此时淀粉膜的抗拉强度为4.11 MPa,断裂伸长率为38%,提高了45%,水蒸气透过系数为0.51 g?mm/(m2?h?kPa),降低了39%。结构分析结果表明淀粉膜体系具有较为开放的交联网络结构,淀粉链优先与柠檬酸与甘油形成的酯结合,此外柠檬酸的水解作用会导致体系网络结构减弱。因此,添加柠檬酸可有效改善复合改性淀粉膜材料的机械性能和阻隔性能,制备出综合性能优良的复合膜,为淀粉基食品包装应用研究提供了理论依据。     

氧气等离子体预处理对UHMWPE/PANI复合纤维导电性能的影响

采用原位聚合法制备了UHMWPE/PANI复合导电纤维。为提高复合纤维的电导率,采用了氧气等离子体对UHMWPE纤维进行预处理,研究了处理时间、反应功率和氧气压强等因素对复合纤维导电效果的影响,并用扫描电镜观察了等离子处理对UHMWPE纤维表面形貌的影响。结果表明：氧气等离子预处理增大了UHMWPE纤维的粗糙度,提高了其表面能,UHMWPE/PANI复合纤维的电导率增大,在功率90W,压强40Pa的处理条件下处理2min,复合纤维的电导率可以达到0.18S/cm。随着等离子体处理时间的延长、反应功率的提高及氧气压强的增大,复合纤维的电导率均呈现先增大后减小的趋势。     

Functional and tableting properties of acetylated and oxidised finger millet (Eleusine coracana) starch

The functional and tableting properties of native (NaFM) and chemically modified (by acetylation, AcFM; and oxidation, OxFM) finger millet starches were investigated. The tablet formation properties of the starches were assessed by Heckel and Kawakita analysis. The swelling power and solubility of the starch increased with increase in temperature with AcFM having the highest swelling power, while OxFM had the highest solubility. X‐ray diffractometry showed that the starches had the characteristic ‘A’ pattern with strong peaks at 3.78, 4.37, 4.87, and 5.17 Å. Chemical modification causes rupture of some starch granules as revealed by the Scanning Electron Micrograph. Chemical modification also leads to improved gelatinisation profile, with reduction in ΔH_gel from 9.64 J/g (NaFM) to 3.88 J/g (AcFM) and 8.76 J/g (OxFM). The bulk density and Hausner's ratio increased after chemical modification of the starch. Chemical modification reduced the mean yield pressure, P_y (Heckel analysis) but increased the deformability P_k (Kawakita analysis) of the starch compacts. Chemical modification also increased the crushing and tensile strength of the starch compacts, but lowered its disintegration time and friability.     

等离子体处理对聚四氟乙烯膜粘接性能的影响

为提高聚四氟乙烯(PTFE)膜的粘接性能,研究了氧气等离子体处理对PTFE膜剥离强度和水接触角的影响, 并比较了氧气、氮气和氩气等离子体处理PTFE膜粘接强度的差异,借助X射线光电子能谱仪、扫描电子显微镜和原子力显微镜测试了等离子体处理前后PTFE膜表面元素、形态和粗糙度的变化。结果表明:氮气等离子体处理的PTFE膜,其剥离强度较未处理的PTFE膜提高了539.8%,水接触角提高了11.4°,达120.4°;当放电量低于36 kJ 时,经氧气等离子体处理的PTFE膜剥离强度随放电量的增加呈指数增加,继续增加放电量时,PTFE膜表面形成了凹凸沟槽的荷叶形貌,该荷叶形貌决定了膜粘结性和疏水性的强弱。     

微波对高链玉米淀粉颗粒抗消化性能的影响

高链玉米淀粉颗粒通过微波改性,调节不同的水分质量分数、微波温度、微波时间和微波功率可以改变淀粉颗粒的抗消化性能。采用扫描电镜和生物体外(invitro)降解方法,对不同微波作用条件下的高链玉米淀粉的颗粒形貌和抗消化性能进行了研究。结果表明,高链玉米淀粉经微波改性后,颗粒形貌发生改变,表面出现凹凸、小孔,当抗消化淀粉质量分数达到22.0%时,大部分淀粉颗粒已经发生破损、崩裂。在微波场中,水分质量分数和微波温度对高链玉米淀粉抗消化性能的影响较大,而微波功率和时间对其影响较小。