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Studies on the Properties of PP/ POSS Melt-Blown Nonwoven Fabric with Permanent Electret Yuan-feng Wang 1 Xiao-yan Song 2 Wei-min Kang 1 Bo-wen Cheng 2 1 School of textileTianjin Polytechnic UniversityTianjin300160China2 State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University, Tianjin, 300160, China Email: [email protected] AbstractNovel PP/POSS nonwoven fabrics with permanent electret were prepared by melt-blown process and Corona charging. The effect on structure of the fibercrystallinitythermal stability and properties of surface charge storage were researched. The results show that diameter of the fiber decreases with increasing POSS and POSS is well dispersed in PP matrix. POSS has a heterogeneous nucleation effect on PP as α nucleating agents and accelerate the crystallization process during nonisothermal cooling. The effects of POSS on the thermal stability of PP nonwoven fabrics, however, are not obvious. The charge density of PP/POSS melt-blown fabrics is obviously higher than that of PP after Corona charge. KeywordsPOSS;nonwoven;electret 耐久驻极 PP/POSS 熔喷非织造布的性能研究 王元峰 1 ,宋晓艳 2 ,康卫民 1 ,程博闻 2 1 天津工业大学纺织学院,天津,中国,300160; 2 中空纤维膜材料与膜过程省部共建国家重点实验室培育基地 ,天津,中国, 300160 Email: [email protected] :制备了新型的耐久驻极 PP/POSS 体熔喷非织造布。研究了 POSS 对其纤维形态、结晶性能、 热稳定性及表面电荷储存能力的影响。结果表明,加入 POSS 后纤维直径减小,且 POSS 均匀分散在 聚丙烯基体中;POSS 作为 α-成核剂起到异相成核的作用,加速了结晶过程,提高了结晶温度;随着 POSS 含量增加,聚丙烯非织造布的热稳定性稍有提高;加入 POSS 后的 PP 熔喷非织造布电晕驻极后 电荷密度明显高于 PP关键词POSS ;非织造;驻极体 1 前言 国际上一致认为熔喷非织造布(无纺布) 是制作 空气过滤器驻极体的最佳材料, 国内主要采用的熔喷 非织造布是熔喷聚丙烯纤维。特别是经过驻极工艺处 理后,能大幅度的提高其过滤效率 [1-3] 。但现有聚丙烯 驻极体熔喷非织造布存在电荷储存性能较差的缺点, 特别是在较高温度或较大湿度的环境下电荷很快就会 衰减,甚至消失,驻极耐久性差,很大程度上影响了 产品的使用寿命加入添加剂作为电荷诱捕陷阱是提 高其驻极体性能 [4] 的有效途径之一。 J Hillenbrand [5] 制备了含有 α-成核剂 NA11CaCO 3 Al 2 O 3 的聚 丙烯驻极体,研究表明添加剂含量达到 10%时,其电 荷储存性能最好。Nico Behrendt [6] 加入 NA11 和玻 璃微球通过双轴拉伸制备了多孔聚丙烯薄膜,其电荷 储存稳定性增加,并且具有压电作用,其压电系数在 17 - 170 pC/N 之间与玻璃微球的粒径、含量及其拉 伸比有关。康卫民等 [7] 发明了一种电气石改性聚丙烯 复合驻极熔喷超细纤维非织造布,该复合驻极体聚丙 烯熔喷非织造布的表面电荷密度明显提高。本文用多 面体倍半硅氧烷(POSS)改性聚丙烯熔喷非织造布, 并对该非织造布电晕充电,制得了一种新型的复合驻 极体熔喷非织造布,并对其结晶性能、热性能及电荷储 存特性进行了详细的研究。 Figure 1. The spatial structure of octavinyl-POSS 图1 8 乙烯基 POSS 的空间结构图 基金项目:科技部 863 项目(2007AA03Z359) 325 The 7th National Conference on Functional Materials and Applications 978-1-935068-41-9 © 2010 SciRes.

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Page 1: Studies on the Properties of PP/ POSS Melt-Blown Nonwoven ... · Studies on the Properties of PP/ POSS Melt-Blown Nonwoven Fabric with Permanent Electret Yuan-feng Wang1, Xiao-yan

Studies on the Properties of PP/ POSS Melt-Blown

Nonwoven Fabric with Permanent Electret

Yuan-feng Wang1, Xiao-yan Song2, Wei-min Kang1, Bo-wen Cheng2

1 School of textile,Tianjin Polytechnic University,Tianjin,300160,China; 2 State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University, Tianjin, 300160, China

Email: [email protected]

Abstract:Novel PP/POSS nonwoven fabrics with permanent electret were prepared by melt-blown process and Corona charging. The effect on structure of the fiber,crystallinity,thermal stability and properties of surface charge storage were researched. The results show that diameter of the fiber decreases with increasing POSS and POSS is well dispersed in PP matrix. POSS has a heterogeneous nucleation effect on PP as α nucleating agents and accelerate the crystallization process during nonisothermal cooling. The effects of POSS on the thermal stability of PP nonwoven fabrics, however, are not obvious. The charge density of PP/POSS melt-blown fabrics is obviously higher than that of PP after Corona charge.

Keywords:POSS;nonwoven;electret

耐久驻极 PP/POSS 熔喷非织造布的性能研究

王元峰 1,宋晓艳 2,康卫民 1,程博闻 2 1天津工业大学纺织学院,天津,中国,300160;

2中空纤维膜材料与膜过程省部共建国家重点实验室培育基地 ,天津,中国, 300160

Email: [email protected]

摘 要:制备了新型的耐久驻极 PP/POSS 体熔喷非织造布。研究了 POSS 对其纤维形态、结晶性能、热稳定性及表面电荷储存能力的影响。结果表明,加入 POSS 后纤维直径减小,且 POSS 均匀分散在聚丙烯基体中;POSS 作为 α-成核剂起到异相成核的作用,加速了结晶过程,提高了结晶温度;随着POSS 含量增加,聚丙烯非织造布的热稳定性稍有提高;加入 POSS 后的 PP 熔喷非织造布电晕驻极后电荷密度明显高于 PP。

关键词:POSS ;非织造;驻极体

1 前言

国际上一致认为熔喷非织造布(无纺布) 是制作

空气过滤器驻极体的最佳材料, 国内主要采用的熔喷

非织造布是熔喷聚丙烯纤维。特别是经过驻极工艺处

理后,能大幅度的提高其过滤效率[1-3]。但现有聚丙烯

驻极体熔喷非织造布存在电荷储存性能较差的缺点,

特别是在较高温度或较大湿度的环境下电荷很快就会

衰减,甚至消失,驻极耐久性差,很大程度上影响了

产品的使用寿命。加入添加剂作为电荷诱捕陷阱是提

高其驻极体性能[4]的有效途径之一。J Hillenbrand 等[5]

制备了含有 α-成核剂 NA11、CaCO3 和 Al2O3 的聚

丙烯驻极体,研究表明添加剂含量达到 10%时,其电

荷储存性能最好。Nico Behrendt 等[6]加入 NA11 和玻

璃微球通过双轴拉伸制备了多孔聚丙烯薄膜,其电荷

储存稳定性增加,并且具有压电作用,其压电系数在

17 - 170 pC/N 之间,与玻璃微球的粒径、含量及其拉

伸比有关。康卫民等[7]发明了一种电气石改性聚丙烯

复合驻极熔喷超细纤维非织造布,该复合驻极体聚丙

烯熔喷非织造布的表面电荷密度明显提高。本文用多

面体倍半硅氧烷(POSS)改性聚丙烯熔喷非织造布,

并对该非织造布电晕充电,制得了一种新型的复合驻

极体熔喷非织造布,并对其结晶性能、热性能及电荷储

存特性进行了详细的研究。

Figure 1. The spatial structure of octavinyl-POSS 图 1 8 乙烯基 POSS 的空间结构图 基金项目:科技部 863 项目(2007AA03Z359)

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2 实验

将 0wt%、1wt%、3wt%的八乙烯基 POSS(结构

如图 1 所示)与 PP 切片高速混合,使用双螺杆挤出

机造粒(Brabender,Germany),然后通过熔喷法并进

行负电驻极(—25KV)制得驻极 POSS/PP 熔喷非织

造布,分别记作 PP、PP1/POSS 和 PP3/POSS。

3 结果与讨论

3.1 非织造布表面形态结构(SEM)

图 2 分别是 PP、PP1/POSS 和 PP3/POSS 的 SEM

照片。纤网呈三维网状结构,纤维之间互相纠缠,纤

网中空隙较多,透气、透湿性好,适合做过滤材料。

从图中可以看出,纯 PP 的熔喷布纤维粗细比较均匀,

纤维之间的空隙比较大,而加入了 POSS 后,纤维平

均直径减小。在 PP1/POSS 中有少量 POSS 聚集在纤

维表面,而 PP3/POSS 中有较多 200-500nm 的 POSS

聚集体且分散比较均匀。

PP

PP1/POSS

PP3/POSS

Figure 2. The surface structure of nonwovens

图 2 非织造布表面结构

3.2 热失重分析

Figure 3. The thermo-gravimetric curves of Polypropylene/POSS

melt-blown nonwovens

图 3 聚丙烯/POSS 熔喷非织造布的热失重曲线

在氮气保护及升温速度 10ºC /min 条件下对聚丙

烯/POSS 复合材料进行了热失重测试,所得到的 TG

曲线如图 3 所示, 随着 POSS 含量的增加,聚丙烯

/POSS复合材料的起始分解温度比纯聚丙烯的稍微有

所提高(5-10 ºC),并且随着 POSS 含量增加残碳量

增加。复合材料热稳定性的提高可能是由于在聚丙烯

表面形成一种坚硬 Si 的保护膜,延缓了聚苯乙烯的分

解和热变形。但是研究表明,纳米粒子需达到一定的

mol%含量,复合材料的热性能才会有大幅度的提高[8],

我们所加的纳米粒子的 mol%含量是非常低的,因此

POSS 对聚丙烯的热稳定性影响不明显。

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3.3 POSS 对聚丙烯非织造布结晶性能的影响

Table 1.The DSC parameters of Polypropylene/POSS melt-blown

nonwovens

表 1 聚丙烯/POSS 熔喷非织造布 DSC 参数

试样 PP PP1/POSS PP3/POSS

结晶峰温度 Tp(℃) 110.2℃ 117.2℃ 118.7℃

熔融热焓△H (J/g) -110.8 J/g -108.7 J/g -107.2J/g

Figure 4.The DSC curves of Polypropylene/POSS melt-blown

nonwovens

图 4 聚丙烯/POSS 熔喷非织造布的 DSC 曲线

图4为降温速度为10℃/min时的纯聚丙烯和聚丙

烯/POSS的非等温结晶曲线,从图中可以看出,纯聚

丙烯在113.8℃和110℃处有两个结晶峰,分别对应PP

α晶和β晶且以β晶为主,相对纯聚丙烯而言,所有

PP/POSS材料在较高温度均出现了一个α结晶峰,但随

POSS含量增加,结晶温度增加不明显,PP3/POSS的

结晶温度比纯聚丙烯提高了8.5 ℃。这说明POSS在聚

丙烯基体中作为α-成核剂起到异相成核的左右,提高

了结晶温度,但限制了β晶的生成。熔融热焓(△H)可

以表征体系的结晶度, POSS的加入对聚丙烯的结晶

度影响不明显。

3.4 表面电荷密度分析

图5是纯聚丙烯和聚丙烯/POSS 熔喷非织造布平

均表面电荷密度在室温下空气中的衰减曲线。可以看

出,驻极熔喷非织造布表面电荷密度的衰减主要发生

在初始阶段(0.5 小时内),后来基本上保持不变。

Figure 5.The Surface charge attenuation curves of melt-blown

nonwovens

图 5 非织造布表面电荷衰减曲线

随着 POSS 含量增加,驻极聚丙烯熔喷非织造布的表

面电荷密度增加,表面电荷耐久性变好。

4 结论

(1) 制备了新型的驻极 PP/POSS 熔喷非织造布,加入

POSS 后,聚丙烯纤维平均直径减小,并且 POSS

在聚丙烯基体中的分散比较均匀。

(2) 加入 POSS 后,聚丙烯熔喷非织造布的热稳定性

稍有提高,POSS 作为成核剂起到异相成核的作

用,加速了结晶过程,结晶温度提高。

(3) 加入 POSS 后,聚丙烯纤网表面电荷密度明显增

加,电荷贮存能力也有所增强。

References(参考文献)

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[2] M Nifuku, Y Zhou, A.K Kisel,et al. Charging characteristics for electret filter materials [J]. Journal of Electrostatics, 2001, 51:200-205.

[3] Z Z Yang, J H Lin, I S Tsai, T Y Kuo,Particle filtration with an electret of nonwoven polypropylene fabric,Textile Research Journal[J], 2002, 72: 1099~1104.

[4] N Mohmeyer, N Behrendt, X Zhang, P Smith, V Altstädt. Additives to improve the electret properties of isotactic polypropylene [J], Polymer, 2007, 48:1612 ~ 1619.

[5] J Hillenbrand, N Behrendt, V Altstädt, H-W Schmidt, G M Sessler, Electret properties of biaxially stretched polypropylene films containing various additives[J], J. Phys. D: Appl. Phys., 2006, 39:535~540.

[6] N Behrendt, V Altstädt, H W Schmidt, X Zhang, Sessler G M., Development of Porous Polypropylene Blends with NA11 Particles and Glass Hollow Spheres by Biaxial Stretching for Electret Applications[J], IEEE Transactions on Dielectrics and Electrical Insulation, 2006, 13: 992~1000.

[7] Bowen Cheng,Weimin Kang,Xiaoning Jiao. Studies on

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melt2blown polypropylene composite fabric containing electret.[J]. Journal of Textile Research,2005,26(5):8-13. 程博闻,康卫民,焦晓宁. 复合驻极体聚丙烯熔喷非织造布的

研究[J]. 纺织学报 26 卷第 5 期. 2005. 8-13. [8] Romo-Uribe A, Mather P T, Haddad T S and Lichtenhan J D

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