PVC表面处理剂的研制

介绍了几种表面处理剂对PVC革剥离强度的影响 ,从中选择出最佳表面处理剂A ,并把处理剂A干燥时间对剥离强度的影响作一讨论 ,确定适宜的干燥时间     

表面处理方法对胶粘剂性能的影响

采用不同的表面处理方法处理粘接接头,在湿热老化条件下通过元素分析法测定了样品中碳、硅、氧的含量,以及对胶粘剂粘接接头剥离强度、吸水率,玻璃化温度等湿热老化性能进行了考查,得出最佳处理粘接接头的方法。     

Effects of different surface treatments of zirconia on the bond strength of self-adhesive resinous cement

Purpose: The aim of this study was to evaluate the effects of different zirconia surface treatments on the bond strength of two self-adhesive resinous cements (SARC).

Methods: Two hundred and eight cylindrical specimens were obtained from Y-TZP zirconia (half with diameter 3.2 mm and half with 4.8 mm). After sintering and polishing, specimens were divided into four groups (n = 26), according to surface treatment: Control (no treatment); Sandblasting (Al₂O₃ particles); Rocatec (Al₂O₃ particles, tribochemical silica coating and silane application); Laser (Nd: YAG laser: 20 Hz, 100 mJ, 0.2 J/cm²). The surface roughness (Ra) was evaluated after the surface treatments, and the groups were divided into two subgroups (n = 13), according to the SARC tested: RelyX U200 and Bifix SE. The 2.2-mm cylinders were bonded to 4.8-mm cylinders and stressed until failure under shear using a universal testing machine. Bond strength and Ra were analyzed using ANOVA, and Tukey’s test (α = 0.05).

Results: Surface treatment was significant (p < 0.0001), but cement type (p = 0.73) was not. Related to roughness, significant differences were found for the treatment type (p < 0.0001), with laser being the treatment with higher Ra values.

Conclusions: Nd:YAG laser produced a rougher surface and a higher bond strength compared with sandblasting, silicatization, and control groups.     

Influence of different surface treatments on zirconia/resin shear bond strength using one-bottle universal adhesive

ABSTRACT

This study was designed to evaluate the effect of different treatments on the zirconia/resin shear bond strength (SBS) using commercial one-bottle universal adhesive. Zirconia discs with different surface treatments (blank control; airborne-particle-abrasion; glazing) were bonded to the bovine enamel surfaces using one-bottle universal adhesive. All specimens were tested for SBS (MPa) before and after 10000 thermocycles. Statistically analysis were conducted by using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). Airborne-particle-abrasion group showed higher SBS (36.19 ± 11.86) than control group (14.98 ± 5.90) and glazing group (10.63 ± 5.39) (p < 0.05). After thermocycling test, the SBS significantly decreased for control group (8.84 ± 2.55) and glazing group (6.18 ± 2.78) while not for airborne-particle-abrasion group (41.5 ± 7.95). One-bottle universal adhesives combined with airborne-particle-abrasion showed quite high SBS of zirconia/resin, which was appropriate for bonding of zirconia restoration.     

响应面法优化复合酶提取牛皮胶原多肽的工艺

以实验室自制的牛皮胶原蛋白为原料,探讨复合酶提取牛皮胶原多肽的工艺。以牛皮胶原蛋白的水解度为评价指标,确定木瓜蛋白酶和胰蛋白酶的添加顺序和添加比例,同时单因素法获取酶解工艺参数的优化区间,响应面法优化复合酶酶法提取胶原多肽的工艺参数,实验结果表明,从牛皮胶原蛋白中提取胶原多肽的最优条件为：木瓜蛋白酶和胰蛋白酶按酶活力比3:1同时添加,加酶量650u/ml,酶解介质pH7.0,酶解温度50℃,酶解时间7h,在此工艺条件下得到的牛皮胶原蛋白的水解度可达到32.02%。     

表面粗糙度对镍镀层结合性能的影响

对玻璃基双层镍表面进行阳极活化以提高镍层之间的结合强度。阳极活化液组成和工艺条件为:NiCl2·6H2O 100 g/L,H3BO3 25 g/L,pH 4.0,温度45°C,阳极电流密度10~30 mA/cm2,时间5~15 min。研究了电流密度和处理时间对镍镀层表面形貌、孤岛结合力、表面粗糙度和界面结合强度的影响,探讨了双层镍表面粗糙度和界面结合强度的关系。结果表明,在30 mA/cm2下阳极活化10 min后,双层镍的界面结合强度为629.8 MPa,比盐酸活化试样高了近2倍。镍层表面粗糙度与界面结合强度之间有明显的对应关系,表面粗糙度越大,界面结合强度越高。采用阳极活化法可有效提高微机电系统微器件的可靠性。     

氨气处理碳纤维 第II报 碳纤维表面和复合材料的性能

常压下,使碳纤维通过以氨气为气体介质的600℃热反应炉,反应停留时间为30s。采用三点短梁法和界面评价装置研究处理前后复合材料的层间剪切强度(ILSS)和界面剪切强度(IFSS),经氨气处理后二者分别提高了13.2%和32.1%。接触角测试结果表明:处理后碳纤维与水和环氧树脂的浸润性得到很大改善。采用扫描电子显微镜(SEM)研究处理前后碳纤维表面和复合材料断裂面形貌的变化,发现氨气处理对碳纤维表面形貌没有影响。力学性能测试数据表明,氨气处理不影响碳纤维的强度。     

聚酯型水性聚氨酯的交联对T剥离强度的影响

用自制的聚氨酯乳液加入各种交联剂,研究了交联剂的种类、用量及热处理对复合薄膜的T剥离强度的影响。     

Surface modification of polyvinyl chloride with biodegradable monomers

Graft copolymerization of sucrose acrylate (SA) onto 55 μm films of poly(vinyl chloride) (PVC) was investigated with benzophenone or 2,2′-azoisobutironitrile as the initiator. The grafting reactions were carried out in a closed cell containing the films to be treated with a solution of the sensitizer and the monomer. In this system, ultraviolet light through a quartz window initiated the reaction by exciting the initiator used. The grafting took place on a PVC surface layer, from the solution. The homopolymer formed during copolymerization was removed by washing. The percentage of grafting was determined by gravimetric measurements and by dye adsorption (crystal violet), and the characterization of PVC(g)SA was carried out by the use of infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis. The weathering behavior of PVC(g)SA was studied with microorganisms in a growing medium, and the degradation was monitored by the weight loss of the films, FTIR, and SEM. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1195–1201, 1997     

木质素筛余物对物料黏度及聚氨酯合成革剥离强度的影响

木质素是聚氨酯合成革中优良的填充剂,其赋予了聚氨酯合成革特殊的物理性能和加工性能,可降低成本。不同的木质素筛余物对木质素/聚氨酯共混体的黏度及聚氨酯合成革的剥离强度有一定的影响,当木质素筛余物质量分数控制在5.5%～6.5%,能得到较佳的作用效果。     

Curing of crust leather by ultraviolet radiation with urethane acrylate: Role of pigment

Eight different formulations were developed with four diacrylate reactive monomers such as tripropylene glycol diacrylate (TPGDA), 1,4‐butanediol diacrylate (BDDA), 1,6‐hexanediol diacrylate (HDDA), and 2‐ethylene glycol dimethacrylate (EGDMA) and aromatic urethane diacrylate (M1100) in order to modify the crust leather surface. To study the effect of pigment on the performance of ultraviolet (UV)‐cured leather surface, 1% pigment (congored) was incorporated in the formulations. Irgacure 369 (2%) was also used in the formulation as photoinitiator. The gel content, tensile strength, elongation at break, and pendulum hardness of UV‐cured thin films with and without pigment was studied. The films without pigment produced better properties. Among all the diluents, BDDA‐containing films showed the best performance. Different properties of UV‐coated leather surface such as pendulum hardness, tensile strength, elongation, gloss (at 20° and 60°), adhesion, and abrasion were studied. Effect of gloss on simulating weathering was also performed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 692–697, 2002     

环保型阻燃湿法合成革的研制

用液态的磷酸酯阻燃剂对涤/棉配比基布进行浸渍处理,处理量占基布质量的5 %（干重比）,可使基布达到美国FMVSS-302阻燃标准的B级阻燃效果。通过6种阻燃剂在聚氨酯树脂中的不同配比试验,考察了不同阻燃剂组合及其用量对聚氨酯树脂阻燃性能的影响。结果表明,氢氧化铝/间苯二酚双/磷酸酯（12/2/2,质量份,下同）复合阻燃剂配方体系所制试样燃烧速度为0 mm/min,阻燃效果可达到A级;将其涂覆于阻燃处理的基布上即可制得环保型阻燃合成革,阻燃性能可以通过多国的阻燃标准。     

Peel strength improvement of foam core sandwich beams by epoxy resin impregnation on the foam surface

The interfacial adhesion characteristics between foam cores and faces affect much the structural integrity of foam core sandwich structures. The peel strength between the face plate and the foam core is one of the appropriate parameters for the interfacial characteristics of sandwich structures and its peel energy is also measured for the interfacial characterization. The peel strength is the first peak force per unit width of bondline required to produce progressive separation, and the peel energy is the amount of energy per unit bonding area associated with a crack opening. In this study, to improve the peel strength between the foam core and the face plate of foam core sandwich beams, the surfaces of foam core sandwich beams were resin-impregnated. Then the peel strength as well as peel energy of resin impregnated polyurethane foam core sandwich beams were measured by the cleavage peel test and compared with those of the same sandwich beams without surface resin impregnation on the foam surface.     

不同金属表面处理对高分子材料与金属连接强度影响

分别利用喷砂、氢氧化钠阳极氧化和激光毛化3种方法对钛合金板进行了表面处理,通过提高其表面粗糙度,来达到提高相应金属–高分子连接件连接强度的目的。其中激光毛化处理能有效提高相应连接件的拉伸性能,而氢氧化钠阳极氧化处理可以有效提高连接件的剥离强度。综合这两种处理方法所制备的金属–高分子连接件的连接强度得到明显提高,拉伸强度为322 MPa,断裂伸长率为5.1%,剥离强度为4.70 N/cm。     

Effect of surface treatments and aging on phase transformation and flexural strength of different Y-TZP ceramics

This study aimed to evaluate the influence of surface treatments and artificial aging on surface roughness (Ra), phase transformation, and flexural strength of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics. Two-hundred and eighty specimens from four types of Y-TZP were divided into seven groups, according to the surface treatments and aging used: control, air-abrasion, air-abrasion + aging, grinding, grinding + aging, erbium: yttrium-aluminum-garnet (Er:YAG) laser, Er:YAG laser + aging. The Ra values were measured using a profilometer. X-ray diffraction (XRD) analysis was performed to determine phase transformation. Specimens were subjected to a three-point bending test and loaded until fracture. Scanning electron microscope (SEM) and atomic force microscope (AFM) analyses were performed on one specimen per group. Grinding and air-abrasion groups exhibited higher Ra values than the others (P < 0.05). The differences in the roughness and flexural strength values between the laser and control groups were not significant. For all materials, the highest amount of monoclinic phase was found after air-abrasion. Grinding groups showed lower flexural strength values compared with the control groups (P < 0.05), while there was no significant difference between the control and air-abrasion groups. Aging did not affect the roughness and flexural strength (P > 0.05). The grinding process is not recommended in clinical usage for Y-TZP because of the remarkable decrease in flexural strength and reliability.     

Effect of different surface shapes formed by femtosecond laser on zirconia-resin cement shear bond strength

Objective: The purpose of this study was to evaluate the effect of different surface shapes formed by femtosecond (FS) laser on zirconia (Y-TZP)-resin cement shear bond strength (SBS). Background data: All ceramic restoration is used as an alternative to metal-ceramic restorations, due to its better aesthetics, strength, and toughness properties. However, bond strength of restoration to tooth and other materials is effective to long term success of the restoration, and to achieve it surface treatment is required on ceramic surface. Materials and methods: Forty square-shaped zirconia samples were prepared and assigned to four groups of 10. The details of the groups are as follows: Group A, square-shaped recessed surface; Group B, square-shaped projection surface; Group C, circular-shaped recessed surface; Group D, circular-shaped projection surface. The SBSs values were performed with a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed statistically using analysis of variance (ANOVA) and Tukey HSD multiple comparisons tests. Results: The one-way ANOVA results on SBSs of the zirconia material bonded with resin cement revealed significant differences among the groups (p < 0.05). The Tukey HSD test results revealed that Group B and D had significantly higher SBS values than other groups (p < 0.05), but there were no significant differences between each other (p > 0.05). Additionally, Group A and C had significantly lower values than other groups (p < 0.05). Conclusions: Different surface shapes formed by FS laser provided a significant increase in SBSs. The SBS values of projection surfaces of circular and square-shapes are greater than that of recessed surfaces of circular and square-shapes.     

Efficacy of uncommon surface treatment methods on titanium in order to improve bond strengths for adhesive cementation

The aim of this study is to comparison of effects of uncommon surface treatments, especially new alternatives on the adhesive strength between resin and titanium surfaces. Fifty-five titanium disks were prepared and they were separated into 5 groups as follows: (1) Control group; (2) Tribochemical treatment group in the laboratory; (3) Tribochemical treatment group in the clinic; (4) Acid etch group; and (5) Nd:YAG Laser-irradiated group. Surface roughness of the specimens was measured using a profilometer, and the topographic patterns were observed by scanning electron microscope. After these tests, resin cement was applied to the titanium samples. Shear bond test was performed via a universal testing machine at a crosshead speed of 0.5 mm/minute. In addition, the correlation between the surface roughness and bond strength was checked using Spearman correlation test (0.01 level). The highest surface roughness value was observed for the acid etch group (1.53 μm). The highest mean shear bond strength was recorded with the tribochemical procedure group in the laboratory (13.74 MPa) and the lowest with the control group (3.69 MPa). A positive correlation was found between the bond strength and surface roughness for all groups. All of the surface treatment methods that were used in present study increased the bond strength between resin and titanium except for the laser group.     

Effect of chemical etching of resistance wire surface on the strength and failure mechanism of the resistance-welded joint of polyetherimide composites

The surface modification of stainless-steel (SS) mesh was carried out by chemical etching for different time, and then, the etched SS meshes were used as the interlayer heating element for resistance welding of glass fabric-reinforced polyetherimide (GF/PEI) composite laminates. The hydrophobicity and tensile strength of the etched and untreated SS wires and interfacial shear strength (IFSS) between SS wire and PEI resin were investigated by dynamic contact angle (DCA) analyzer and single fiber pull-out test to evaluate the influence of the degree of chemical etching on the bonding strength of PEI resin and SS surface. Tensile lap-shear strength (LSS) and scanning electron microscope (SEM) analysis were performed to investigate the welding interface strength and fracture morphologies of the resistance-welded joint of the GF/PEI laminates. The hydrophobicity and tensile strength of SS wires were increased and decreased respectively with etching time (t_e). The IFSS of SS wire/PEI resin showed an improvement with t_e. The LSS was increased first and then decreased with t_e, and the optimal t_e was 30 min when LSS reached the maximum. Fracture analysis showed the main failure mode of the welded joints was the interlayer debonding when welding time (t_w) was insufficient. With the extension of t_w, the failure mode gradually switched into the intralayer tearing of the SS implant. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47879.     

Effect of surface cold ablation on shear strength of CFRP adhesively bonded joint after UV laser treatment

Ultraviolet(UV) laser treatment on the surface of the carbon fiber reinforced polymer (CFRP) laminate becomes an effective method to benefit the bonding strength of adhesively bonded joint in aerospace industries. In the present research, homomorphic CFRP laminates with different resin distribution on the surface are bonded into single-lap joints. Their shear strengths are tested to evaluate the effect of surface resin distribution on bonding mechanical performance. The different resin distributions on the surface of CFRP laminate are obtained by UV pulse laser with different laser scanning speeds. The scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are conducted to analyze the laser treated surfaces and fracture surfaces of tested joints. The experimental results indicate that the residual resin of CFRP surface increases with the increase of scanning speed. Compared with both the reference surface without laser pre-treatment and that with no-residual resin for bonding, the surface with partial residual resin results in an enhancement of the shear strength of bonded joint. Moreover, the shear strength of the reference sample is higher than that bonded by the surface with no-residual resin. The research lays foundation for understanding the relationship between surface resin distribution and bonding strength.     

Effect of alcohol leachable chloride on strength of magnesium oxychloride cement

The major crystalline phases in magnesium oxychloride cement (MOC) have been extensively studied, but the other phases have not been studied due to the difficulty in identifying them. In the current study, we focused on the effect of chlorine-containing phases other than crystalline oxychlorides on the strength of cured MOC materials. The alcohol leachable chloride (ALC) was proposed to characterize the other phases containing chlorine, and the absolute ethanol leaching test was developed to determine ACL content in a cured MOC paste. The results showed that either decreasing MgO/MgCl₂ molar ratio or increasing H₂O/MgCl₂ molar ratio led to an increase in ALC content in cured MOC slurry, but adding a small amount of phosphoric acid resulted in very little or almost no ALC in the modified MOC slurry. In addition, increasing ALC content has been shown to significantly reduce the compressive strength of hardened MOC pastes. Thus, the modified MOC pastes had high strength, compared with the corresponding common MOC pastes. According to the experimental results, the relationship between the ALC content and the compressive strength of cured MOC materials was established. Therefore, a low ALC content was proposed as a characteristic index of high-quality MOC materials.