Modification of Montmorillonite with Poly(Oxypropylene) Amine Hydrochlorides: Basal Spacing, Amount Intercalated, and Thermal Stability

Abstract

Few studies have explored the change in thermal stability of poly(oxypropylene) (POP) ammonium ions after intercalation, even though several studies have focused on the modification of montmorillonite (Mt) with POP amine hydrochloride. The purpose of the present study was to understand the effect of chain length of POP amine hydrochlorides on the basal spacing of modified Mt, and the amount and thermal stability of the ammonium ions intercalated. The relations between basal spacing, organic fraction, and thermal stability of the ammonium ions intercalated were also explored. Series of modified Mt were prepared via ion-exchange between Na+-montmorillonite (Na+-Mt) and POP diammonium ions or POP triammonium ions with different chain lengths, and were then characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, and simultaneous differential scanning calorimetry-thermogravimetric analysis. The results revealed that the basal spacing of modified Mt increased with the hydrophobic chain length of the POP ammonium ions. The amount of triammonium ions intercalated was close to the theoretical amount, while the organic fraction of modified Mt was directly proportionalto the basalspacing of modified Mt. The intercalated ammonium ions were, therefore, contained within the interlayer space ofMt. After intercalation, the thermal stability of the POP ammonium ions with various chain lengths was reduced; i.e.Tonset was reduced by 7–60°C for short-chain POP ammonium ions (D400 and T403) and by 177–192°C for long-chain ions (D2000, D4000, T3000, and T5000).

Study on the effect of poly(oxypropylene)diamine modified organic montmorillonite on curing kinetics of epoxy nanocomposties

“…Similarly, POP ammonium ion to Na + is also at the molar ratio of 1:1. More detailed procedure was described in previous work [13]. The modified MMT were labeled according to the poly(oxypropylene) diamine as given below: D400-MMT and D2000-MMT.…”

“…Among various organic chemicals used in modification of MMT, a number of studies have been carried out on the use of poly (oxypropylene) amine as an intercalating agent in the last decades [9][10][11][12]. Compared to the most common surfactants of alkylammonium salts, the application of poly(oxypropylene) amine to modify MMT could further expand the basal spacing and the modified MMT with a basal spacing of up to 8.5 nm have been obtained [13]. On the basis of the significantly expanding interlayer spacing and improving compatibility with polymer matrix, the exfoliated nanocomposites can be prepared readily, including epoxy/MMT nanocomposites [14] .…”

Modification of Montmorillonite with Alkyl Silanes and Fluorosurfactant for Clay/fluoroelastomer (FKM) Nanocomposites

“…Considering a mass loss of 5% as the onset degradation point, silane modification clearly brought about an increase in the thermal stability of the CPN, relative to Cloisite 20A. The use of ammonium ions as a surfactant for clay treatment, however, has a negative effect on the thermal stability of the CPN (Wang et al, 2011). Moreover, the use of carbon black as the second filler caused a decrease in the temperature at which degradation began.…”

Co-intercalation of Montmorillonite by Poly(oxypropylene) Amine Hydrochlorides with Different Chain Length

“…图 7 D400-MMT, T5000-MMT 和 D400-T5000-MMT 的 XRD Figure 7 XRD curves of D400-MMT, T5000-MMT and D400-T5000-MMT 由图 6 和图 7 可知, 当一种聚醚铵盐插层 MMT 时, 随插层剂聚醚铵阳离子链长的增加, 改性 MMT 的层间 距依次增加 [12,13] . 然而, 当两种不同链长的聚醚铵阳离 子(D2000 和 D400, 或 T5000 和 D400)协同插层 MMT [12,13] , 同时也说明了 插层剂阳离子与 MMT 中的 Na ＋ 之间的离子交换较为完 全. 进一步分析, 发现一个有趣的现象, 即协同插层蒙 脱土 D400-D2000-MMT 的有机含量小于 D2000-MMT, 而 D400-T5000-MMT 的有机含量大于 T5000-MMT.…”

“…进一步分析, 发现一个有趣的现象, 即协同插层蒙 脱土 D400-D2000-MMT 的有机含量小于 D2000-MMT, 而 D400-T5000-MMT 的有机含量大于 T5000-MMT. 分 析其原因, 一方面, 可能是由于 T5000 吸附于 MMT 层 间, 不仅使层间距扩大, 而且由于其支链结构, 比长链 的 D2000(倾斜排布 [13] )更有利于提高改性 MMT 的层间 空隙, 从而使更多的 D400 短链聚醚铵阳离子通过离子 …”