PVC/HfA/MMA/nano-Al(OH)_3复合材料性能的研究

采用丙烯酸六氟丁酯(HfA)和甲基丙烯酸甲酯(MMA)在纳米Al(OH)3(nano-Al(OH)3)颗粒进行表面聚合,使nano-Al(OH)3表面成亲油性,从而与聚氯乙烯(PVC)颗粒的相容性得到提高。在PVC聚合后期加入这种改性剂,纳米粒子包覆在PVC颗粒表面,改性PVC的综合性能得到改善。最佳试验反应条件为:HfA/MMA/nano-Al(OH)3的配比为3∶5∶92,PVC聚合后期加入占改性PVC树脂含量8%的HfA/MMA/nano-Al(OH)3复合材料,制备出的改性PVC树脂混合料的力学性能和耐热抑烟性能均比空白样品大幅提高。     

表面聚合改性纳米碳酸钙增韧PVC的研究

采用丙烯酸六氟丁酯/丙烯酸丁酯对纳米碳酸钙颗粒进行表面聚合改性,在聚氯乙烯(PVC)聚合后期加入表面改性纳米碳酸钙,生产出增韧改性PVC。结果表明:丙烯酸六氟丁酯/丙烯酸丁酯/纳米碳酸钙质量比为2∶8∶90,PVC聚合后期加入10%的改性纳米碳酸钙,制备的PVC复合材料的韧性最好。     

掺杂氟和银的二氧化钛复合抗菌剂粉体的制备与性能研究简

介绍了一种掺杂氟和银的二氧化钛复合抗菌剂粉体的制备方法,包括如下步骤：①先将无水乙醇和乙酸混合后搅匀,得到混合液;取钛酸丁酯滴入上述混合液中,得到浅黄色溶胶;②将氟化银,四丁基氟化铵滴加入浅黄色溶胶中,得到新溶胶;③将放置2～3天后的溶胶用去离子水清洗,过滤;干燥,得到氟银共掺杂纳米二氧化钛塑料抗菌剂.在聚氯乙烯聚合后期加入这种抗菌剂,纳米粒子包覆在PVC颗粒表面,改性PVC的抗菌性能得到改善.掺杂氟和银的二氧化钛复合抗菌剂粉体的最佳组分为：Ag,5％;F,3.5％;SiO2,91.5％,改性PVC树脂中掺杂氟和银的二氧化钛复合抗菌剂粉体的含量为5％.可得到抗菌PVC树脂.     

掺杂氟和银的二氧化钛复合抗菌剂粉体的制备与性能研究

介绍了一种掺杂氟和银的二氧化钛复合抗菌剂粉体的制备方法,包括如下步骤:①先将无水乙醇和乙酸混合后搅匀,得到混合液;取钛酸丁酯滴入上述混合液中,得到浅黄色溶胶;②将氟化银,四丁基氟化铵滴加入浅黄色溶胶中,得到新溶胶;③将放置2～3天后的溶胶用去离子水清洗,过滤;干燥,得到氟银共掺杂纳米二氧化钛塑料抗菌剂。在聚氯乙烯聚合后期加入这种抗菌剂,纳米粒子包覆在PVC颗粒表面,改性PVC的抗菌性能得到改善。掺杂氟和银的二氧化钛复合抗菌剂粉体的最佳组分为:Ag,5%;F,3.5%;SiO2,91.5%,改性PVC树脂中掺杂氟和银的二氧化钛复合抗菌剂粉体的含量为5%。可得到抗菌PVC树脂。     

硅基抗菌粉体表面改性及对聚氯乙烯塑料抗菌性能影响

用硅烷偶联剂KH570对硅基抗菌粉体进行表面有机化改性,研究了偶联剂用量、反应时间及反应温度对表面改性效果的影响.通过润湿性和吸光度测定,确定了最佳表面改性条件:硅烷偶联剂KH570含量为2份(100 g粉体中加入的改性剂量),反应温度为80℃,反应时间为5 h.通过红外光谱(FTIR)、热重(TG)和透射电镜(TEM)等对改性前后的粉体表面结构、热性能及在聚氟乙烯(PVC)中分散性分析表明:KH570以化学键形式接枝到粉体表面,形成了有机包覆,改变了粉体表面的极性;改性后的抗菌粉体在PVC中的分散性得到了提高,使其抗菌性增强.     

ChMI/MMA/St/HfA提高PVC耐热性能研究

通过在N-环己基马来酰亚胺/甲基丙烯酸甲酯/苯乙烯(ChMI/MMA/St)三元共聚物聚合过程中加入微量的含氟单体丙烯酸六氟丁酯(HfA)进行共聚,在共聚物骨架上引入氟元素,生产出共聚物用于改性聚氯乙烯(PVC)树脂。试验证明,三元共聚物和四元共聚物均可提高PVC树脂混合物玻璃化温度(tg)和维卡软化温度(tVicat);耐热改性剂中HfA加入可提高PVC混合料的加工性能;四元共聚物加入量占PVC树脂混合物15%(质量分数,下同),相当于加入三元共聚物25%的效果,可大大降低PVC耐热制品的成本。     

新品开发

上海开发出新型抗菌PVC塑料华东理工大学超细材料制备与应用教授部点实验室和上海氯碱化工股份有限公司合作,开发成功纳米复合抗菌聚氯乙烯功能塑料制备技术,制备出抗菌性能优异的聚氯乙烯塑料。这一新技术日前通过上海市科委主持的专家鉴定。他们将纳米抗菌粉体研磨分散和湿法处理相结合,针对无机抗菌粉体,开发了湿法复合表面改性新技术。利用钛酸酯类偶联剂和硬脂酸对载银二氧化钛抗菌粉体进行复合改性,改善了抗菌粉体在聚氯乙烯基体中分散性能及界面相容性,提高了抗菌粉体聚氯乙烯的拉伸和冲击强度等力学性能。首次将载银磷酸锆纳米抗…     

国内外简讯

上海开发出新型抗菌PVC塑料华东理工大学超细材料制备与应用教授部重点实验室和上海氯碱化工股份有限公司合作 ,开发成功纳米复合抗菌聚氯乙烯功能塑料制备技术 ,制备出抗菌性能优异的聚氯乙烯塑料。这一新技术日前通过上海市科委主持的专家鉴定。他们将纳米抗菌粉体研磨分散和湿法处理相结合 ,针对无机抗菌粉体 ,开发了湿法复合表面改性新技术。利用钛酸酯类偶联剂和硬脂酸对载银二氧化钛抗菌粉体进行复合改性 ,改善了抗菌粉体在聚氯乙烯基体中分散性能及界面相容性 ,提高了抗菌粉体聚氯乙烯的拉伸性能和冲击强度等力学性能。首次将载银…     

纳米ZnO/PVC自粘保鲜膜抗菌性能的研究

采用纳米氧化锌((ZnO)与聚氯乙烯(PVC)复合制得纳米抗菌自粘保鲜膜,并对其抗菌性能和物理力学性能进行了研究。结果表明,纳米ZnO/PVC自粘膜具有长效抗菌和广普抗菌性,且当纳米ZnO的用量为2phr时,其抗菌率最高,同时自粘膜的力学强度和防雾性能也明显提高。     

多元纳米PVC材料的制备及其性能研究

采用原位聚合法将硅烷偶联剂(KH-570)包覆在纳米Ti O2和Mg(OH)2表面,并将其分散于聚氯乙烯(PVC)基体中。通过红外光谱、X射线衍射及扫描电镜对添加纳米颗粒前后的PVC材料进行表征。结果表明,Mg(OH)2的加入能够促使纳米Ti O2与其交联,从而减少纳米颗粒的团聚,提高纳米颗粒的分散性能。同时对PVC材料进行紫外屏蔽性能实验以及氧指数的测定实验,其结果表明,当纳米Ti O2和Mg(OH)2质量比为1∶2时,材料的紫外屏蔽性能与阻燃性能最佳。     

PVC/竹粉复合材料制备

在固相反应器中对竹粉进行机械活化乙酰化改性,将改性竹粉与聚氯乙烯(PVC)混合均匀,热压成型制备PVC/竹粉复合材料。考察催化剂浓硫酸用量、乙酸酐用量、机械活化时间和温度对复合材料力学性能的影响,并对改性前后的竹粉及其复合材料断面进行表征。结果表明,当乙酸酐与改性竹粉的物质的量之比为3.5︰1、机械活化温度为80℃、机械活化时间为60 min、催化剂浓硫酸用量为乙酸酐质量的0.5%时,复合材料的弯曲强度为41.29 MPa,拉伸强度为20.87 MPa;傅立叶变换红外光谱分析表明,竹粉被成功进行乙酰化改性。X射线衍射分析表明,机械活化降低了竹粉结晶度,无定形区增加,提高了反应活性;扫描电子显微镜分析表明,在机械力作用下,竹粉纤维束被打断,比表面积增加;改性竹粉复合材料的断面形貌分析表明,竹粉在PVC中分散较均匀,无团聚现象,复合材料断面上没有空隙,改性竹粉与PVC粘结性较好。     

PVC干混料粉体流动性的影响因素

介绍了与粉体流动性有关的理论,分析了PVC树脂、CPE、碳酸钙和冷混工艺对PVC干混料粉体流动性的影响,结果表明:①乙烯法PVC树脂的粉体流动性一般优于电石法PVC树脂,且波动较小;②某些厂家的冲击改性剂CPE可改善PVC干混料的粉体流动性,并且随着CPE用量的增加,PVC干混料的粉体流动性增加;③不同生产厂家的PVC/CPE体系对PVC干混料粉体流动性的影响规律不同,应不断摸索,找出最佳组合;④随着碳酸钙用量的增加,PVC干混料的粉体流动性降低,特别是在料斗上的表现更为突出;⑤充分冷却后的PVC干混料粉体流动性较好。     

硫酸钡表面改性及其在PVC中的性能研究

使用γ-氨丙基三乙氧基硅烷(KH-550)、γ-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)、γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH-570)以及硬脂酸(SA)对沉淀硫酸钡(BaSO4)粉末进行表面处理,并使用接触角测试仪、管式炉和红外光谱仪对改性BaSO4进行表征。进一步将改性BaSO4添加到聚氯乙烯(PVC)中,研究了它们对PVC/BaSO4复合材料基本力学性能的影响,并分析了复合材料冲击截面的断裂面形貌。结果表明,改性BaSO4的表面接触角显著增大,红外光谱显示有基团峰出现,质量损失率明显变大,其中SA的改性效果最佳,接触角为134.5°,质量损失率为4.65%。和添加未改性BaSO4的PVC复合材料相比较而言,添加改性BaSO4的PVC复合材料的拉伸性能和撕裂性能均有所增强,硬度变化不大,其中,总体上SA的表面改性效果最佳,PVC/BaSO4复合材料的拉伸强度、撕裂强度和邵氏D硬度分别达到28.68 MPa、151.03 N/mm、70.2。复合材料断裂表面的扫描电子显微镜分析表明,经过改性的BaSO4粉末在复合材料中的分散性变得更好。     

Low pressure rheology of granular powders using a drawing plate technique

An analysis of a drawing plate test for easily monitoring the low-pressure frictional characteristics of powders is presented. The test is performed by measuring the force required to withdraw a plate from a cylindrical bed of dry powder. The characteristics of the drawing force profile are analyzed using Janssen's classical differential element approach to relate the product μK of powders as a function of packing of powder medium, where μ is the coefficient of friction of the powders against the solid drawing plate, and K is Janssen's constant, an anisotropic pressure distribution factor of a powder bed. The packing arrangement, expressed as the external void fraction, due to tapping, significantly alters the μK value and the effective sustaining strength of a powder bed. Experimental results on spherical glass beads having mono- and bimodal size distributions, and on three different poly (vinyl chloride) (PVC) powders are discussed. A spherical, high bulk density PVC powder has the combination of low μK and high, bulk density desirable for rigid powder compounding applications.     

Effect of poly(vinyl chloride) resin type in the preparation process of slush powder

During the preparation of the poly(vinyl chloride) (PVC) slush powder, we found that PVC resins obtained by different polymerization methods affected many properties of slush powder and its products. Two types of commercial PVC resins were used for slush powder preparation: mass poly(vinyl chloride) (M‐PVC) and suspension poly(vinyl chloride) (S‐PVC). We used the Haake rheomix test to characterize the absorption of plasticizers into PVC resins, and the results showed that M‐PVC absorbed the plasticizers more quickly than S‐PVC. The fusion behavior of the two slush powders was studied by the thermal plate test and Haake rheomix test, and the results showed that the slush powder of M‐PVC was easier to fuse than that of S‐PVC. The different properties of the two resins and slush powder could be explained by the morphology, average size, and size distribution. Due to the “skin” of the particles' surfaces, the wider size distribution, and the large size of particles, S‐PVC absorbed the plasticizers more slowly and was more difficult to fuse. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3331–3335, 2002     

Plasticizer diffusion into PVC particles as studied by ESR spin probe method

Summary The spin probe technique of electron spin resonance (ESR) spectroscopy has been applied for studying the plasticizer diffusion, migration, and redistribution processes in suspension polymerized PVC particles. In the first series of experiments six PVC powder samples with different K values (58, 61, 64, 67, 70, and 72) were mixed with diisooctyl phthalate (DOP) containing 10^–4 M 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) as stable free radical spin probe. In the second run TEMPO-doped dry PVC powders were mixed with DOP plasticizer. Finally we studied the plasticizer transport phenomena between plasticized and non-plasticized polymer particles in powder mixtures. The observed diffusion properties of different samples were interpreted in terms of the different porosities of powders.     

PVC powder extrusion. Melting properties and particle morphology

The extrusion of unplasticized PVC powder has been studied. Powder blends with low amounts of lubricants have been used in order to observe differences between structurally different PVC powders. Experiments with varying screw speeds indicate that resins consisting of agglomerated, small, globular primary particles are more sensitive to shear and deformation in the extruder channel than more compact particles. Frictional heat seems to be dissipated inside loosely agglomerated resin particles, possibly because of a larger internal surface. This additional heat, which depends on the shear rate, influences the melting behavior considerably. Scanning electron microscopy shows that PVC particles seem to melt without first breaking into smaller particles. A comparison between bulk-polymerized and suspension-polymerized PVC with nearly the same particle structure reveals a close similrity in melting properties. The results obtained in this work indicate that structural differences may explain the differences in melting behavior often observed when rigid PVC blends are extruded.     

不同处理工艺的滑石粉对PVC/ABS合金性能的影响

研究了滑石粉的不同处理工艺对聚氯乙烯(PVC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)合金的力学性能和耐热性能的影响,用SEM观察PVC/ABS合金的冲击断面微观形貌和滑石粉的分散情况。研究表明,经偶联剂改性后的滑石粉对PVC/ABS合金的力学性能要好于未改性的。但是,经偶联剂改性后滑石粉制备的PVC/ABS合金维卡软化温度反而低于未经表面处理的。     

Enhanced the antifouling and antibacterial performance of PVC/ZnO-CMC nanoparticles ultrafiltration membrane

Inorganic nanoparticles (NPs) have been employed in modification for polyvinyl chloride (PVC) membrane intrinsic hydrophobicity. Carboxymethyl chitosan (CMC), a natural organic matter, was used to relieve the agglomeration of zinc oxide (ZnO) NPs in the membrane matrix. In this paper, ZnO-CMC NPs were successfully prepared via co-precipitation approach, blended with PVC membranes, and the effect of ZnO-CMC NPs for the membrane properties was studied. The SEM and EDX confirmed excellent dispersion of ZnO-CMC NPs on the membrane surface. The enhanced hydrophilicity, porosity and inter-connected finger-like strcture of modified membranes confirmed by water contact angle and SEM. In addition, pure water flux of PVC/ZnO-CMC composite membrane was 107.36 L m⁻² h⁻¹ (PVC/ZnO-CMC (0.25 wt%)), which was higher than that of neat PVC membrane (83.11 L m⁻² h⁻¹). Importantly, the modified membranes exhibits lower static BSA adsorbtion because of the improved hydrophilicity, and a higher flux recovery rate (>90%) after three sequential filtration cycles. The antibacterial behavior of PVC/ZnO-CMC membrane was tested simply using Escherichia coli, and the results indicated that all composite membranes possess excellent antibacterial properties. Our work presents PVC/ZnO-CMC NPs composite membrane a promising future in wastewater treatment and antibacterial application.