外文翻譯--濕強(qiáng)紙二酐和二酸的發(fā)展（英文）

1、Materials Chemistry and Physics 88 (2004) 239–243Development of wet-strength paper with dianhydride and diacidS. ZakariaFaculty of Science and Technology, School of Applied Physics, Universiti Kebangsaan Malaysia, 43600,

2、 UKM Bangi, Selangor, MalaysiaReceived 17 June 2003; received in revised form 5 August 2003; accepted 8 September 2003AbstractCellulose is the major component in papermaking. The hydroxyl groups in cellulose are easily r

3、eacted with anhydride to form an ester bond via esterification process. The addition of anhydride and diacid in cotton cellulose were found to give a good wet-strength development. The esterification process between dian

4、hydride and hydroxyl group in cotton cellulose proceed even at room temperature. However, the reaction of diacids requires much higher temperature for the cross-linking process to occur. The FT-IR spectra in the reacted

5、samples show bands at 1720 and 1580 cm?1, which are due to the ester carbonyl and carboxylate carbonyl, respectively. Increasing the conditioning temperature to 130 ?C cause the water retention value in the reacted sampl

6、es decreased tremendously. The percentage of wet-strength development for BTD and BTCA at 110 ?C for 15 min treatment is 41 and 27.7%, respectively. Increasing the temperature above 110 ?C has resulted the fibre to deter

7、iorate further hence reduced the dry strength of the fibres. © 2003 Published by Elsevier B.V.Keywords: Cellulose material; FT-IR; Wet-strength; Physical property1. IntroductionIn the early days when paper was used

8、exclusively for writing, printing and illustrating, wet-strength paper has lit- tle importance. As the use of the paper became wider, it be- came apparent that some of these uses were benefited if the paper possessed gre

9、ater strength when wetted. The introduc- tion of formaldehyde containing compounds as wet-strength resins, which was started in the late 1930s, opened the door to the mass production of wet-strength paper. The use of wet

10、-strength paper is important in the preparation of facial tissues, towels, boxes, bags and other products, which re- quire strength when they are wetted. Since cellulose has many hydroxyl groups, the requirement of the c

11、hemicals to be used as wet-strength agents can also react with them- selves to form a cross-linked network once the paper is dried. Cross-linking is important in paper for the production of wet-strength, also increases t

12、he dimensional stability. In the textile industry, cross-linking is required for durable and crease-resistance in the fabrics. It will also reduce the mois- ture regain in the fabrics due to the decreased number of hy- d

13、roxyl group available to interact with water molecules [1].E-mail addresses: sarani@pkrisc.cc.ukm.my, sarani zakaria@yahoo.com (S. Zakaria).The typical reactions on modification of cellulose are es- terification and ethe

14、rification at hydroxyl groups of cellu- lose. The esterification reaction of cellulose with anhydrides such as alkenylsuccinic anhydrides (ASA) and alkylketene dimers (AKD) as an active sizing agent has been reported by

15、many researchers [2]. These reactive sizes are added as a cationic emulsion to the paper stock. The esterifica- tion of these sizing chemicals and cellulose fibre require heat treatment, which is occurred during the dryi

16、ng process in the papermaking. During the esterification process, the ASA will react with one of the cellulose hydroxyl group to form an ester bond (by breaking the anhydride ring), which is sometime known as ASA-cellulo

17、se half ester. How- ever, ASA will easily hydrolyse in water to form ASAcid. While AKD form AKD-cellulose ?-keto ester upon reac- tion with cellulose and hydrolyse in water rapidly to form ketone. Benzophenone tetracarbo

18、xylic dianhydride (BTD) has two anhydrides groups. Each of this group is attached on each side of the benzene ring and is expected to ester- ify with cellulose. BTD will hydrolyse rapidly in water. The hydrolysis product

19、 consists of four carboxylic acid groups. The preparation of BTD involves a condensa- tion process of ortho-xylene with acetaldehyde, in the presence of acid as a catalyst. This process will produce 1,1-bis(3,4-dimethyl-

20、phenyl) ethane with it, then further0254-0584/$ – see front matter © 2003 Published by Elsevier B.V. doi:10.1016/j.matchemphys.2003.09.035S. Zakaria / Materials Chemistry and Physics 88 (2004) 239–243 241Fig. 2. FT-

21、IR spectra of BTCA reacted with cotton fibre at different conditioning temperatures and further treatment with diluted NaOH: (A) 70; (B) 110; (C) 130 ?C.strip after each test was recorded. The opacity measure for the tre

22、ated paper and untreated paper was measured by using a Carl Zeiss Photoelectric reflectance photometer Elrepho.3. Results and discussionWhen esterification takes place between the diacid and cotton cellulose, the carboxy

23、l group may exist in three forms that are carbonyl ester (COOR), carboxyl (COOH) and car- boxylate (COO?M+). Figs. 1 and 2 show the FT-IR spec- tra of BTCA in cotton paper without and with treatment with NaOH, respective

24、ly. The carbonyl ester band appears in the region 1721 cm?1, which is overlapped with the car- bonyl band in the same region 1720–1721 cm?1. However, the carboxylate band appeared to be far away from this re- gion, which

25、 is in the region of 1584 cm?1. The treatment of the treated samples with dilute NaOH has converted the free carboxyl group in the paper into carboxylate, which shifted the band away from the ester carbonyl at 1720–1585

26、cm?2(Fig. 2). There is no reaction between BTCA and cotton cel- lulose at 70 ?C. However, by increasing the temperature up to 110 ?C, a sharp peak at 1720 cm?1 (which corresponds to the ester carbonyl and carboxyl band)

27、is observed. Fur- ther increase in heat conditioning temperature (130 ?C) re- sulted in the increase in the intensity of the ester carbonyl band. However, the carboxyl band intensity is observed to decrease. This could b

28、e due to further esterification of car- boxyl groups in BTCA with cotton fibre. This shows clearly in the calculation of the peak absorbance ration of the ester carbonyl band (Table 1). Taking the peak 897 cm?1, whichTab

29、le 1 The ester carbonyl band intensity ratio and carboxylic acid intensity ratio of paper treated with BTCAConditioning temperature (?C)87 110 130Ratio ester carbonyl band: 1720 cm?1/899 cm?1 Trace 3.0641 5.7785Ratio car

30、boxylate carbonyl band: 1573 cm?1/899 cm?1 Trace 0.6664 0.2768is characteristic of the ?-1, 4-link of the cellulose repeating unit [6] as internal standard, the absorbance peak ratio of the ester carbonyl and carboxylate

31、 can be calculated as shown in Table 2.Fig. 3 shows the FT-IR spectra of cotton paper treated with BTD at different heating temperatures. Spectrum A represents the untreated fibre, which acts as a control. Spec- trum B i

32、s the reaction of cotton fibre at room temperature. It is shown that the peak at 1720 cm?1 is due to esterTable 2 The carbonyl intensity ratio (ester/carboxylate) of the treated paper with BTDConditioning temperature (?C

33、)60 80 100 130Carbonyl band intensity: 1720 cm?1/1580 cm?1 0.1899 0.2006 0.2197 0.4631Ratio ester carbonyl band: 1720 cm?1/899 cm?1 0.0891 0.2915 1.3651 4.5188Ratio carboxylate carbonyl band: 1580 cm?1/899 cm?1 0.2753 1.