黄原胶辐射接枝NVP及其对酚类物质吸附的研究

VIP免费

3.0 牛悦 2024-11-19 4 4 2.84MB 77 页 15积分

侵权投诉

摘要

本文以黄原胶为基材，N-乙烯基吡咯烷酮为接枝单体，利用辐射法制备了黄

原胶-N-乙烯基吡咯烷酮接枝共聚物（XG-g-NVP），研究了影响接枝共聚反应的

因素，利用红外光谱分析，热重分析，扫描电镜和 X射线衍射对接枝共聚物进行

了结构表征。利用流变仪分析了可溶性接枝共聚物的流变特性；并测定了不溶性

水凝胶的溶胀特性。通过静态吸附实验，测定了接枝共聚物吸附苯酚和多酚物质

的能力，并对其应用于茶饮料和苹果汁澄清做了初探。

研究表明吸收剂量对接枝率的影响极为显著，在黄原胶浓度及 NVP/XG 质量

比一定的情况下，接枝率随剂量的增加而增加，并逐步达到平衡；在吸收剂量和

NVP/XG 质量比一定时，接枝率在黄原胶浓度为 10 g/L 达到最大；在吸收剂量和

黄原胶浓度一定时，接枝率在质比为 10:1 达到最大值。

红外光谱研究表明接枝反应发生在 NVP 乙烯基部位，接枝共聚物保留了 NVP

的内酰胺结构。热重分析表明接枝共聚物的热稳定性得到了增强，碳化温度显著

升高。XG-g-NVP 接枝共聚物的电镜扫描图片表明，接枝后黄原胶由片状逐步变为

颗粒状，且接枝共聚物的内部为层状结构。XG-g-NVP 接枝共聚物的 X射线衍射

图谱表明接枝反应发生在黄原胶分子的侧链，且结晶度随着接枝率的增加而增加。

在低接枝率下，XG-g-NVP 共聚物保留了水溶特性，接枝共聚物的流变分析表

明接枝后黄原胶的抗高温和抗剪切的能力得到了提高。高接枝率下，XG-g-NVP

可形成水凝胶，接枝率为 623%时，其吸水能力越强，吸水速率最快，25℃下的最

大溶胀度为 62.1g/g。接枝率高于 623%时，随着接枝率的增加 XG-g-NVP 的溶胀

度逐渐下降。

XG-g-NVP 与酚类物质作用的部位发生在 NVP 的内酰胺基团。接枝共聚物吸

附苯酚的最适 PH 值为 5；吸附多酚类物质的 PH 值应控制在弱酸性环境中，PH 值

在4~6 之间。在接枝率为 623%时，XG-g-NVP 吸附酚类的量最多。苯酚和茶多酚

的浓度为 10mg/mL 时，XG-g-NVP 对其的吸附量分别为 0.76g/g 和2.85g/g。相对

于苯酚，XG-g-NVP 更容易吸附茶多酚。XG-g-NVP 对酚类的吸附符合 Freundlich

方程，吸附属于单分子层吸附，吸附过程属于物理吸附。添加少量 XG-g-NVP 即

可达到对茶汤和苹果汁澄清的目的。

关键词：黄原胶 N-乙烯基吡咯烷酮辐射接枝苯酚多酚吸附

ABSTRACT

In this paper, Xanthan gum-N-vinylpyrrolidone graft copolymer (XG-g-NVP) was

prepared by irradiation. Xanthan gum was taken as the base material and NVP was

taken as the single body. The effects of different reaction conditions on the grafting

yield were explored. The structure of the grafted copolymers was characterized by

Fourier-Transform Infrared Spectroscopy (FT-IR), Thermo gravimetric analysis (TGA),

Scanning electron microscopy (SEM) and X-Ray Diffraction (XRD). The viscosity

behavior of solution was investigated by the rheometer; and the swelling property of

XG-g-NVP copolymer was also measured. Under static conditions, grafting copolymer

property of adsorbing pHenols was studied, which could be applied in tea beverage and

apple juice's clarification.

The research showed that the absorbed dose had the significant effect on the

grafting yield. Under the certain xanthan gum concentration and NVP/XG mass ratio

situations, the grafting yield increased with absorbed dose and gradually achieved to the

balance; under the certain absorbed dose and mass ratio conditions, the grafting yield

reached maximum at the xanthan gum concentration of 10g/L; under certain irradiation

and xanthan gum concentration situations, grafting yield reached the maximum at

NVP/XG mass ratio of 10:1.

FT-IR picture showed that grafting reaction occurred in NVP vinyl part and lactam

structure was retained. Thermo gravimetric analysis showed that XG-g-NVP enhanced

thermal stability of xanthan gum and the carbonization temperature of xanthan gum

went up. SEM pHotograpHs showed that after grafting, the structure of xanthan gum

gradually became grain-like in shape from flake-like, of which the inner part was

slice-like in shape. XRD showed the crystallinity increased after grafting and the

grafting reaction may be occurred at the side chain of XG.

At low grafting yield, the XG-g-NVP copolymer's water dissolvable characteristic

was remained and viscosity behavior analysis of XG-g-NVP showed that temperature

and shear resistance of grafting copolymer was better than xanthan gum. At grafting

yield of 623%, XG-g-NVP had the best swelling property and the fastest velocity of

absorbing water, of which the swelling degree was 62.1 g/g at 25 ℃. When grafting

yield was higher than 623%, the swelling degree of XG-g-NVP was decreased as the

increase of grafting yield.

The reaction of pHenols with XG-g-NVP was taken place at the lactam group of

NVP. The most suitable pH of absorbing phenol was at pH5.0. The PH value of

adsorbing polyphenol material should be controlled in the weak acidity environment,

which pH value was at 4.0~6.0. At grafting yield of 623%, XG-g-NVP had the

maximum adsorption capacity of pHenol and tea polypHenol, which adsorption amount

were 0.76g/g and 2.85g/g respectively at the pHenols concentration of 10 mg/mL.

Compared with phenol, tea polyphenol was more easily absorbed by XG-g-NVP. The

isotherm data of absorbing phenols were fitted to Freundlich model, which means that

the adsorption was a single molecule layer adsorption and the process was a physical

adsorption. Adding a little amount of XG-g-NVP can immediately attain the purpose of

clarifying the tea soup and apple juice.

Key Word：Xanthan gum，NVP，Irradiation grafting，Phenol，

PolypHenol，Adsorption

摘要

ABSTRACT

第一章绪论.................................................................................................................1

§1.1 黄原胶的结构、性质与应用..............................................................................1

§1.1.1 黄原胶的结构 .............................................................................................. 1

§1.1.2 黄原胶的性质 .............................................................................................. 2

§1.1.3 黄原胶的应用 .............................................................................................. 2

§1.2 黄原胶接枝改性方法及研究现状......................................................................4

§1.2.1 黄原胶的化学接枝改性 .............................................................................. 4

§1.2.2 黄原胶的化学接枝改性研究现状 .............................................................. 4

§1.2.3 黄原胶的物理接枝改性 ............................................................................... 6

§1.2.4 黄原胶的物理接枝改性研究现状 .............................................................. 6

§1.3 辐射接枝简介......................................................................................................7

§1.3.1 辐射接枝基本概念 ...................................................................................... 7

§1.3.2 共辐射接枝 .................................................................................................. 8

§1.3.3 预辐射接枝 .................................................................................................. 8

§1.3.4 辐射接枝应用现状及研究成果 .................................................................. 9

§1.4 NVP 及其聚合物性能与应用...........................................................................10

§1.4.1 NVP 的结构与性质 .................................................................................... 10

§1.4.2 NVP 聚合物的性能与应用 ........................................................................ 11

§1.5 本文研究目的与研究内容...............................................................................13

第二章 XG-g-NVP 接枝共聚物的制备与表征........................................................... 14

§ 2.1 引言...................................................................................................................14

§ 2.2 材料与方法.......................................................................................................14

§ 2.2.1 实验装置与材料 ........................................................................................ 14

§ 2.2.2 实验方法与内容 ..................................................................................... 14

§ 2.2.2.1 影响接枝率的因素 ................................................................................. 14

§ 2.2.2.2 不同接枝率 XG-g-NVP 水凝胶的制备 ............................................ 15

§ 2.2.2.3 接枝共聚物结构表征 ..........................................................................15

§ 2.3 实验结果与分析 ..............................................................................................16

§ 2.3.1 影响黄原胶接枝的因素 ........................................................................... 16

§ 2.3.1.1 吸收剂量对接枝率的影响 ..................................................................16

§ 2.3.1.2 NVP/XG 质量比对接枝率的影响........................................................16

§ 2.3.1.3 XG 浓度对接枝率的影响.....................................................................17

§ 2.3.2 不同接枝率 XG-g-NVP 水凝胶的制备 ...................................................18

§ 2.3.3 接枝共聚物结构表征................................................................................................ 18

§ 2.3.3.1 接枝共聚物红外图谱扫描 .................................................................18

§ 2.3.3.2 接枝共聚物电镜扫描 .........................................................................19

§ 2.3.3.3 接枝共聚物热重分析 .........................................................................21

§ 2.3.3.4 接枝共聚物 X射线衍射分析 ............................................................ 22

§ 2.4 本章小结 ..........................................................................................................23

第三章 XG-g-NVP 接枝共聚物的物理性能 ..................................................................24

§ 3.1 引言...................................................................................................................24

§ 3.2 材料与方法.......................................................................................................24

§ 3.2.1 实验装置与材料 ........................................................................................ 24

§ 3.2.2 实验方法与内容 ..................................................................................... 24

§ 3.2.2.1 接枝共聚物表观粘度的测定 .............................................................24

§ 3.2.2.2 接枝共聚物溶胀速率曲线的测定 .....................................................25

§ 3.2.2.3 接枝共聚物溶胀度的测定 .................................................................25

§ 3.2.2.4 接枝共聚物持水能力的测定 .............................................................26

§ 3.3 实验结果与分析 ..............................................................................................26

§ 3.3.1 黄原胶-NVP 接枝共聚物流变性 .............................................................. 26

§ 3.3.1.1 接枝率对流变性的影响 .....................................................................26

§ 3.3.1.2 剪切速率对表观粘度的影响 .............................................................26

§ 3.3.1.3 温度对表观粘度的影响 .....................................................................28

§ 3.3.2 XG-g-NVP 的溶胀性能..........................................................................28

§ 3.3.2.1 接枝共聚物的溶胀速率 .....................................................................29

§ 3.3.2.2 接枝率对溶胀性能的影响 .................................................................29

§ 3.3.2.3 温度对溶胀性能的影响 .....................................................................30

§ 3.3.2.4 接枝共聚物耐盐性分析 .....................................................................30

§ 3.3.2.5 PH 值对 XG-g-NVP 溶胀性能的影响 ...................................................31

§ 3.3.3 接枝共聚物的持水能力 ........................................................................... 32

§ 3.4 本章小结 ..........................................................................................................32

第四章 XG-g-NVP 对苯酚的吸附 ..................................................................................34

§ 4.1 引言...................................................................................................................34

§ 4.2 材料与方法 ......................................................................................................34

§ 4.2.1 实验材料 ................................................................................................... 34

§ 4.2.2 仪器与设备 ............................................................................................... 34

§ 4.2.3 XG-g-NVP 对苯酚的吸附.........................................................................34

§ 4.2.3.1 苯酚标准曲线 .....................................................................................34

§ 4.2.3.2 时间对 XG-g-NVP 吸附苯酚的影响 ................................................ 34

§ 4.2.3.3 接枝率对 XG-g-NVP 吸附苯酚的影响 ............................................ 35

§ 4.2.3.4 PH 值对 XG-g-NVP 吸附苯酚的影响 ............................................... 35

§ 4.2.3.5 XG-g-NVP 吸附苯酚的红外图谱分析 .............................................. 35

§ 4.2.3.6 XG-g-NVP 吸附苯酚的热力学参数 .................................................. 35

§ 4.3 结果与分析 ....................................................................................................36

§ 4.3.1 标准曲线 ..................................................................................................36

§ 4.3.2 时间对 XG-g-NVP 吸附苯酚的影响 ..................................................... 36

§ 4.3.3 接枝率对 XG-g-NVP 吸附苯酚的影响 ................................................. 37

§ 4.3.4 PH 值对 XG-g-NVP 吸附苯酚的影响 ....................................................37

§ 4.3.5 XG-g-NVP 接枝共聚物吸附苯酚的红外分析....................................... 38

§ 4.3.6 温度对 XG-g-NVP 吸附苯酚的影响 ..................................................... 39

§ 4.3.7 吸附热力学 ..............................................................................................40

§ 4.4 本章小结 .........................................................................................................41

第五章 XG-g-NVP 接枝共聚物对多酚类物质的吸附 ..................................................43

§ 5.1 引言 ..................................................................................................................43

§ 5.2 材料与方法 ......................................................................................................43

§ 5.2.1 实验材料 ................................................................................................... 43

§ 5.2.2 仪器与设备 ............................................................................................... 44

§ 5.2.3 XG-g-NVP 对茶多酚的吸附.....................................................................44

§ 5.2.3.1 茶多酚标准曲线 .................................................................................44

§ 5.2.3.2 时间对 XG-g-NVP 吸附茶多酚吸附的影响 .................................... 44

§ 5.2.3.3 接枝率对 XG-g-NVP 吸附茶多酚的影响 ......................................... 44

§ 5.2.3.4 pH 值对 XG-g-NVP 吸附茶多酚的影响 ............................................44

§ 5.2.3.5 XG-g-NVP 吸附茶多酚的红外图谱分析 .......................................... 45

§ 5.2.3.6 XG-g-NVP 吸附茶多酚的热力学参数 .............................................. 45

§ 5.2.4 XG-g-NVP 对茶汤的澄清.........................................................................45

§ 5.2.4.1 茶汤的制备 .........................................................................................45

文档加载中……请稍候！
如果长时间未打开，您也可以点击刷新试试。

下载文档到电脑，查找使用更方便

15 积分 4人已下载

立即下载 VIP免费下载

摘要：

摘要本文以黄原胶为基材，N-乙烯基吡咯烷酮为接枝单体，利用辐射法制备了黄原胶-N-乙烯基吡咯烷酮接枝共聚物（XG-g-NVP），研究了影响接枝共聚反应的因素，利用红外光谱分析，热重分析，扫描电镜和X射线衍射对接枝共聚物进行了结构表征。利用流变仪分析了可溶性接枝共聚物的流变特性；并测定了不溶性水凝胶的溶胀特性。通过静态吸附实验，测定了接枝共聚物吸附苯酚和多酚物质的能力，并对其应用于茶饮料和苹果汁澄清做了初探。研究表明吸收剂量对接枝率的影响极为显著，在黄原胶浓度及NVP/XG质量比一定的情况下，接枝率随剂量的增加而增加，并逐步达到平衡；在吸收剂量和NVP/XG质量比一定时，接枝率在黄原胶浓度为10...

展开>> 收起<<

黄原胶辐射接枝NVP及其对酚类物质吸附的研究.pdf

共77页,预览8页

还剩页未读，继续阅读

黄原胶辐射接枝NVP及其对酚类物质吸附的研究

相关推荐

开通VIP享超值会员特权

作者详情

相关内容

推荐作者

热门标签

举报选择: