有光和半消光尼龙6切片的非等温结晶动力学研究

采用差示扫描量热仪研究了尼龙6(PA 6)有光切片和半消光切片的非等温结晶行为,用Jeziorny法和Liu法对其动力学进行了分析,并用Friedman方程计算了非等温结晶活化能(E)。结果表明:二氧化钛的加入对PA 6切片的结晶起到促进作用,提高了其结晶速率;少量二氧化钛的加入对PA 6切片的晶体生长方式没有很大影响,PA 6半消光切片的E的平均值较有光切片的低约13.1 k J/mol。     

聚四氟乙烯双向拉伸膜生化隔离防护服的研究

介绍了聚四氟乙烯双向拉伸膜的制备工艺、成孔机理、隔离防护机理和透湿机理,综述了聚四氟乙烯双向拉伸膜生化隔离防护服的研究,并对发展前景进行了展望。     

索氏萃取折光法测锦纶6切片中热水可萃取物含量

锦纶6切片在特制的索氏萃取器中经热水萃取后可在折光仪上测定萃取液的折光率,从而可计算得到热水可萃取物的含量。分析了PA6切片质量和萃取时间对热水可萃取物含量的影响。结果表明,PA6切片经热水萃取时,当切片质量为20 g、萃取8 h时可获得较好的萃取效果,且测试结果准确。     

11-氨基十一酸改性PA6的制备及性能研究

以己内酰胺、水、己二酸为原料,11-氨基十一酸作为改性剂聚合得到改性尼龙6(PA6),随后通过熔融纺丝成形后制备了改性PA6纤维,并对改性的PA6切片、纤维和织物进行了表征。结果表明:经11-氨基十一酸改性后,PA6切片中热水可萃取物的质量分数降低了3%,切片的饱和吸水率下降了大约5%,熔融温度从221.50℃下降到206.20℃,结晶温度从184.11℃下降到165.26℃,PA6纤维的模量和断裂伸长率下降,断裂强度有所提高;织物的硬挺度、弯曲刚度和弯曲滞后矩减小,说明改性后PA6织物的柔软性能变好,手感更活络。     

国外聚丙烯薄膜应用

聚丙烯薄膜是聚丙烯树脂消耗的主要用途之一。日本是消费聚丙烯薄膜最多的国家。1979年,日本消耗了21.31万吨,比1978年增长23.9%;其次是西欧市场,消耗14.5万吨,比1978年增长20%;美国消耗12.3万吨,比1978年增长13%。聚丙烯薄膜分双向拉伸膜、单向拉伸膜、未拉伸膜及复合膜。双向拉伸膜由于     

改性多壁碳纳米管／PA6纤维的制备及力学性能

将多壁碳纳米管(MWNT)氧化后,酰氯化处理,在氨基封端的PA6聚合时加入,制备PA6／MWNT母粒,将母粒同PA6切片熔融共混纺丝,制备PA6／MWNT纤维。用INSTRON 1122型万能材料试验机测定纤维的力学性能。结果表明,改性MWNT的加入提高了PA6纤维的断裂强度,纤维中MWNT质量分数仅为0．05％时,纤维的断裂强度和初始模量最大,分别增加了60％和86％。用扫描电镜观察复合纤维的结构,发现MWNT均匀地分布在PA6中,并与PA6基体间有相互作用,沿纤维轴向取向。     

TiO_2表面改性对聚酰胺6纤维强度及染色性能的影响

将TiO2表面包覆无定形TiO2,再经复配偶联剂改性后,分散在己内酰胺-水体系中乳化,于聚合釜中水解开环聚合,得到全消光聚酰胺6(PA6)切片。PA6切片经熔融纺丝制得PA6全消光纤维,并织成PA6全消光织物。用热重分析仪、纳米激光粒度仪、沉降试验等研究了改性TiO2的性能及在己内酰胺-水体系中的分散性;用差示扫描量热仪、扫描电子显微镜等研究了PA6全消光纤维结晶性能和截面形貌。结果表明:经复配偶联剂改性的TiO2在树脂基体中有很好的分散性;PA6全消光纤维的可纺性好;加入改性的TiO2后,PA6纤维的强度提高了25%,但对PA6纤维的熔融温度没有影响;改性PA6全消光织物的上染率提高了10%。     

TiO2表面改性对聚酰胺6纤维强度及染色性能的影响

将TiO2表面包覆无定形TiO2,再经复配偶联剂改性后,分散在己内酰胺-水体系中乳化,于聚合釜中水解开环聚合,得到全消光聚酰胺6(PA6)切片。PA6切片经熔融纺丝制得PA6全消光纤维,并织成PA6全消光织物。用热重分析仪、纳米激光粒度仪、沉降试验等研究了改性TiO2的性能及在己内酰胺-水体系中的分散性;用差示扫描量热仪、扫描电子显微镜等研究了PA6全消光纤维结晶性能和截面形貌。结果表明：经复配偶联剂改性的TiO2在树脂基体中有很好的分散性;PA6全消光纤维的可纺性好;加入改性的TiO2后,PA6纤维的强度提高了25 %,但对PA6纤维的熔融温度没有影响;改性PA6全消光织物的上染率提高了10 %。     

纳米复合金属氧化物/聚酰胺6复合纤维的制备及性能

用共沉淀法制备了锌铝、锌镁铝及镁铝层状双氢氧化物(LDHs),将LDHs经过500℃煅烧后,得到相应的纳米复合金属氧化物(MMO)。MMO经偶联剂表面改性后,与聚酰胺6(PA6)切片共混造粒、熔融纺丝制备MMO/PA6复合纤维,并织造了MMO/PA6织物。用差示扫描量热仪(DSC)、扫描电子显微镜(SEM)以及红外成像仪等研究了MMO/PA6复合纤维的热性能、横截面形貌及MMO/PA6织物的红外辐射性能。结果表明:MMO/PA6复合纤维的可纺性好;加入MMO后,PA6复合纤维的强度下降约10%,但对PA6纤维的熔融温度没有影响;MMO的加入显著提高了PA6纤维的红外辐射性能,60℃保温的MMO/PA6织物,当MMO的质量分数为2.0%时,其温度高于空白PA6织物约2.0℃,具有优异的远红外辐射性能。     

固相增黏环境氧含量对超高黏尼龙6薄膜晶点的影响

以相对黏度为3.3的尼龙6(PA 6)切片为原料,在不同氧含量环境下,通过固相增黏制备超高黏尼龙6(PA 6)切片,并利用小型实验室吹膜机制得相应超高黏PA 6薄膜,研究了环境氧含量对超高黏PA 6切片熔融结晶行为、紫外性能,以及相应超高黏PA 6薄膜晶点数和晶点形貌的影响。结果表明：超高黏PA 6切片的结晶起始温度、结晶峰温度、结晶焓随环境氧含量的提高先增大后下降;超高黏PA 6薄膜的晶点数随着环境氧含量的提高而增多,当环境氧含量大于10 mg/kg时,超高黏PA 6薄膜的晶点数超过3个/cm²,无法满足使用要求;室温下超高黏PA 6切片薄膜的晶点呈带状,当温度升至300℃,晶点周围PA 6完全融化,但晶点仍保持形态不变;PA 6切片在热氧的作用下发生交联反应形成凝胶物质是导致晶点形成的主要原因。     

The linear tearing properties of biaxially oriented PA6/MXD6 blending films

The main purpose of this work was to investigate the linear tearing properties of PA6/MXD6 films prepared by simultaneous biaxial stretching. The compatibility between PA6 and MXD6 and the thermal properties of the PA6/MXD6 composites were also investigated. The results showed that the tearing deviation of the blending films decreased from 100 to 3.8% when the MXD6 blend ratio increased from 0 to 25%, but the deviation increased when the MXD6 blend ratio continue to increase. It means that the PA6/MXD6 films with addition of 25 wt% MXD6 exhibited the best linear tearing properties. The differential scanning calorimetry results revealed that the addition of MXD6 reduced the melting temperature from 227.5 to 224.8°C and crystallization temperature of PA6 from 179.3 to 175°C due to the benzene ring structure of MXD6. The dynamic mechanical analysis results indicated that MXD6 exhibits favorable compatibility with PA6. In addition, it was found that the barrier properties of the biaxially oriented PA6/MXD6 films were extremely improved with the increase of MXD6 content.     

Preparation of biaxially oriented polyamide 6/polyketone/graphene oxide films with enhanced barrier and mechanical behaviors

In this study, biaxially oriented polyamide 6/polyketone/graphene oxide (PA6/PK/GO) films were prepared by melt blending then simultaneously biaxially stretched process, with the aim of obtaining high barrier properties films and improvements in their mechanical properties. The oxygen transmission rate of biaxially oriented PA6/PK/GO film significantly decreased with addition of polyketone and GO. It is surprising that the biaxially oriented process can excellently improve the barrier properties of biaxially oriented PA6/PK/GO film. For example, there was 94.7% OTR reduction of the film containing 20 wt% PK and 0.08 wt% GO compared with PA6 film at a stretching ratio of 3.3 × 3.3. It is due to more tortuous permeation path of oxygen molecule owing to molecular orientation during biaxially stretching, and higher relative crystallinity with addition of GO. The tensile strength of film was remarkablly improved by stretching orientation and increase GO concentration. However, the elongation at break of film was considerably reduced by increase of stretching ratio. Although addition of GO may slightly improve the elongation at break of film at low stretching ratio, there was dramatic decline of elongation at break with increasing the content of GO at a stretching ratio of 3.3 × 3.3.     

Trichroic infrared analysis of the strain-induced structural changes in the PA6 layer of PA6/PE multilayer films under biaxial drawing

This work deals with the structural evolution under biaxial drawing of PA6/tie/PE multilayer films as a function of composition. The occurrence of plastic instabilities in the PA6 layer in the multilayers is strongly reduced with respect to the PA6 monolayer film and the maximum biaxial drawability of PA6 is considerably improved with increasing PE layer thickness. Quantitative evaluation by trichroic infrared analysis of the various crystal forms of the PA6 component shows that the strain-induced β-α crystalline phase transition is delayed in the multilayers, i.e. equivalent level of phase transformation is reached at higher strains. Similar phenomenon is observed regarding the orientation within the film plane of the PA6 chains in the strain-induced α-crystals, i.e. equivalent chain orientation is reached at higher strains in the multilayers. The deformation synergism between the PA6 and PE layers is discussed in terms of benefiting effect from the PE layer that prevents plastic instabilities and promotes homogeneous deformation accompanied with orthotropic extension of the chains in the PA6 layer. This is the driving force to the delay of the detrimental β-α phase transition of PA6, the mechanically anisotropic α-crystals being highly crack-prone in contrast to the ductile isotropic β-crystals. Film rupture is shown to occur when the PA6 strain-induced α-crystals reach a constant content of about 10%, irrespective of film composition and draw temperature in the range 80-110 °C. This kind of critical phenomenon is assigned to a percolation process of the crack-prone α-crystals.     

双轴取向聚乙烯薄膜晶体取向的二维X光衍射分析

聚乙烯膜的晶体取向决定着薄膜的多种力学性能和热力学性能。因此,针对薄膜晶体取向的表征显得非常重要,尤其是具有双轴取向的聚乙烯薄膜。通过二维广角衍射研究了单轴和双轴高取向聚乙烯薄膜的取向度。建立表征取向度的三种方法,包括Herman取向分析法、局部积分法和环向积分法。结果发现,上述方法均适用于所有的双轴取向的高分子薄膜,包括非晶态高分子薄膜。Herman取向分析法可以通过取向因子定量计算简单取向材料取向度;局部积分的方法能分析出衍射较弱方向晶体信息,更适用于取向度较复杂的样品;环向积分法能更直观地分析薄膜的取向特点、取向强度。     

高速BOPP专用料的开发

利用4个反应器串联的Hypol工艺进行高速BOPP专用料的研制开发，通过聚合工艺参数的调整，生产高速BOPP专用料YF3003；从常规物性、热行为、核磁共振谱、相对分子质量及其分布、加工性能等几方面对YF3003试验料和进口高速BOPP料A，B进行分析表征。结果表明．YF3003的物理性能及加工性能与进口料相当，同时，YF3003的加工应用试验也证明它能满足高速BOPP薄膜的生产，且薄膜的热收缩性能特别优异。     

影响锦纶6拉伸变形丝染色性能的主要因素

从原料、工艺、设备等方面入手,对影响锦纶6拉伸变形丝(DTY)染色性能的主要因素进行分析和试验论证。实践证明:切片是影响DTY染色性能的关键因素,纺丝温度及速度、DTY热箱温度、拉伸比对DTY丝上染率影响较大,预取向丝(POY)、DTY质量稳定性对染色均匀性影响也较大。     

气相法工艺BOPP专用树脂的开发和生产

介绍了新一代适宜高速膜生产线的双向拉伸聚丙烯产品F3002，F2002，通过调整聚合工艺条件和对产品内在结构的性能分析，找到了提高膜专用树脂成膜性的技术关键，摸索出了生成超大分子量的可靠控制方法。F3002，F2002的熔体流动指数分别为2．4－3．0，2．0－2．4g/10min，屈服拉伸强度大于等于29MPa，等规指数为95．5％－97．5％，产品适宜于线速300m/min以上的双向拉伸薄膜生产线。     

Si/Ti的调节对生产BOPP专用树脂的影响

在Hypol工艺聚丙烯中试装置上，通过调节外给电子体与主催化剂的进料比例。探讨了Si/Ti对聚合物等规指灵敏，性能，灰分，流动性及催化剂活性等的影响。试验结果表明：用TK-240催化剂生产聚丙烯时，聚合物的等规指灵敏是可调的；等规指数大于95.0%时，粉料流动良好。该聚合物熔体流动指数（2.16kg负荷）为2-4g/10min。等规指数值为95.0%-97.5%。分子量分布宽度为6-8，具有良好的力学性能，并满足双向拉伸聚丙烯专用树脂的要求。     

Effects of the biaxial orientation on the mechanical and optical properties and shrinkage of polyamide 6-66–montmorillonite–nanosilica nanocomposite films

Polyamide 6–66 (PA6-66)–montmorillonite (MMT)–nanosilica (NS) nanocomposite films were fabricated through a cast film process and then biaxially stretched on a laboratory stretcher. Uniaxial or biaxial stretching induced the elongated conformation of MMT and NS. The b axis of the α crystals and the amorphous phase were revealed to align along the machine direction (MD) after stretching, with the uniaxial orientation playing a more significant role. Furthermore, the crystallinity of PA6-66 stretching increased with the stretching ratio. Uniaxial stretching gave rise to a significantly enhanced tensile strength along the MD, whereas it slightly decreased the mechanical properties along the transverse direction (TD). In contrast, the films subjected to biaxial stretching exhibited more balanced mechanical properties. Uniaxial and biaxial stretching led to decreased transmittance and increased haze in the PA6-66–MMT–NS films; this could have been due to the elongated nanostructure of the two nanofillers, which inhibited the transmission and facilitated the scattering of visible light. The thermal shrinkage of the films increased with increasing stretching ratio, and the biaxially oriented films presented nearly equal shrinkage in the MD and TD. The addition of nanofillers decreased the shrinkage attributed to the mobility inhibition of the polymer chains during heating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47504.     

22 dtex/35 f超细旦PA6 FDY高速纺工艺探讨

采用自制的专用母粒与尼龙6(PA6)切片共混纺丝,通过调整工艺参数,在高速纺设备上纺制了规格为22 dtex/35 f超细旦PA6全拉伸丝(FDY);对PA6及专用母粒的干燥、纺丝温度、组件压力、侧吹风速度等工艺条件对超细旦PA6 FDY生产的影响进行了研究。结果表明:在纺制超细旦PA6 FDY时,选择孔径为0.22 mm,长径比为2.5的喷丝板,纺丝温度为260℃,纺丝速度为4 200 m/min,侧吹风温度约为28℃,速度约为0.30 m/s,相对湿度为75%时,生产稳定,产品质量优良,纤维断裂强度为4.92 cN/dtex,断裂伸长率为36.3%,条干不匀率为1.21%。