成人免费777777被爆出-久久大香香蕉国产-国产av久久久久精东av-中国真实偷乱视频-欧美内射rape视频-免费1级a做爰片观看

影響膠粘劑粘接強度的化學因素

時間:2019-04-22 來源:http://www.bjrcc.com.cn/ 發布人:昌盛機械

全自動封膠機廠家提示大家,影響膠粘劑粘接強度的化學要素主要指分子的極性、分子量、分子外形(側基幾及大小)、分子量散布、分子的結晶性、分子對環境的穩定性(轉變溫度和降解)以及膠粘劑和被粘體中其它組份性質PH值等。
The manufacturer of automatic sealing machine reminds us that the chemical factors affecting the bonding strength of adhesives mainly refer to the polarity, molecular weight, molecular shape (side group number and size), molecular weight dispersion, molecular crystallinity, molecular stability to the environment (transition temperature and degradation), and the properties of adhesives and other components in the adhesives, such as PH value.
1、極性。膠粘劑和被粘體分子的極性影響著粘接強度,但并不意味著這些分子極性的增加就一定會進步粘接強度。從極性的角度動身為了進步粘接強度,與其改動膠粘劑和被粘體全局部子的極性,還不如改動界面區外表的極性。例如聚乙烯、聚丙烯、聚四氟乙烯經等離子外表處置后,外表上產生了許多極性基團,如羥基、羰基或羧基等,從而顯著地進步了可粘接性。
1. Polarity. The polarity of adhesives and adhesives affects the bonding strength, but it does not mean that the increase of the polarity of these molecules will certainly improve the bonding strength. In order to improve the bonding strength, it is better to change the exterior polarity of the interface area than to change the polarity of the adhesive and the global part of the adhesives. For example, polyethylene, polypropylene and polytetrafluoroethylene (PTFE) have been treated by plasma. Many polar groups, such as hydroxyl, carbonyl or carboxyl groups, have been produced on the surface, which greatly improves the bondability.
2、分子量。聚合物的分子量(或聚合度)直接影響聚合物分子間的作用力,而分子間作用力的大小決議物質的熔點和沸點的上下,決議聚合物的玻璃化轉變溫度Tg和熔點Tm。聚合物無論是作為膠粘劑還是作為被粘體,其分子量都影響著粘接強度。
2. Molecular weight. Molecular weight (or degree of polymerization) of polymers directly affects the intermolecular forces of polymers, and the magnitude of intermolecular forces determines the melting point and boiling point of materials, and the glass transition temperature (Tg) and melting point (Tm) of polymers. Whether polymer is used as adhesives or as adhesives, its molecular weight affects the bonding strength.
3、側鏈。長鏈分子上的側基是決議聚合物性質的重要要素。從分子間作用力思索,聚合物支鏈的影響是,當支鏈小時,增加支鏈長度,降低分子間作用力。當支鏈到達一定長度后,開端結晶,增加支鏈長度,進步分子間作用力。這應當是降低或進步粘接強度的緣由。
3. Side chain. The side groups on long chain molecules are important factors to determine the properties of polymers. Considering the intermolecular forces, the effect of polymer branched chains is to increase the length of branched chains and reduce the intermolecular forces when the branched chains are small. When the branched chain reaches a certain length, it begins to crystallize, increases the length of the branched chain, and improves the intermolecular force. This should be the reason for reducing or improving the bonding strength.
4、PH值。關于某些膠粘劑,其PH值與膠粘劑的適用期有較為親密的關系,影響到粘接強度和粘接壽命。普通強酸、強堿,特別是當酸堿對粘接資料有很大影響時,對粘接常是有害的,特別是多孔的木材、紙張等纖維類材更容易受影響。

全自動封膠機
4, pH value. As for some adhesives, their PH value has a close relationship with the application life of the adhesives, which affects the bonding strength and bonding life. Ordinary strong acid and alkali, especially when acid and alkali have a great impact on bonding data, are often harmful to bonding, especially porous wood, paper and other fibers are more vulnerable.
由于像熱固性的酚醛樹脂和脲醛樹脂的固化過程受PH值的影響很大,常常請求酸度較大。例如,固化時在酚醛樹脂中參加對甲苯磺酸或磷酸,在脲醛樹脂中參加氯化銨或鹽酸。因而,在不希望酸度大又要粘接的場所,選用中性的間苯酚甲醛樹脂是適合的。
Because the curing process of phenolic and urea-formaldehyde resins, such as thermosetting resins, is greatly affected by the PH value, the acidity is often requested. For example, p-toluene sulfonic acid or phosphoric acid is added to phenolic resin during curing, and ammonium chloride or hydrochloric acid is added to urea-formaldehyde resin. Therefore, it is suitable to use neutral m-phenol formaldehyde resin in places where acidity is not expected to be high and adhesion is required.
將木材外表預先用堿處置,普通可得到結實的接頭。但還必需留意膠層的PH值,它對膠層比對被膠接外表更有影響。
The wood appearance can be pre-treated with alkali, and generally a strong joint can be obtained. However, it is necessary to pay attention to the PH value of the adhesive layer, which has more influence on the surface of the adhesive layer than on the bonded surface.
5、填料。在膠粘劑中配合填料有如下作用:(1)增加膠粘劑的內聚強度;(2)調理黏度或工藝性(例如觸變性);(3)進步耐熱性;(4)調整熱收縮系數或收縮性;(5)增大間隙的可填充性;(6)給予導電性;(7)降低價錢;(8)改善其他性質。
5. Filling. The fillers in the adhesives have the following functions: (1) increasing the cohesive strength of the adhesives; (2) adjusting the viscosity or technological properties (such as thixotropy); (3) improving the heat resistance; (4) adjusting the thermal shrinkage coefficient or shrinkage; (5) increasing the fillability of the gap; (6) giving conductivity; (7) reducing the price; (8) improving other properties.
本文精彩內容由全自動封膠機整理提供!希望通過小編的介紹對大家有所幫助,我們的官網是:http://www.bjrcc.com.cn多謝大家的閱讀觀看!
The wonderful content of this article is provided by automatic sealing machine. Hope to help you through the introduction of the edition, our official website is: http://www.bjrcc.com.cn Thank you for reading and watching!

聯系我們Contact us

  • 咨詢熱線:0531-85717458 13705446998
  • 公司地址: 山東省德州市齊河安頭鄉企巢工業園
  • 掃碼聯系我們:

截屏,微信識別二維碼

微信號:13705446998

// 主站蜘蛛池模板: 色偷偷色噜噜狠狠成人免费视频 | 国产一区二区三区影院| 91福利免费观看| 欧美老妇乱辈通奷| 大乳丰满人妻中文字幕日本| 中文字幕无码免费久久| 蜜桃视频无码区在线观看| 欧美日本日韩aⅴ在线视频| 日本国产制服丝袜一区| 成人国产亚| 熟妇人妻无码xxx视频| 粗大猛烈进出高潮视频| 欧美 日韩 亚洲 精品二区| 色偷拍 自怕 亚洲 10p| 色综合久久无码五十路人妻| 伊人情人色综合网站| 欧美大屁股熟妇bbbbbb| 国产熟女乱子视频正在播放| 久久久久欧美国产高潮| 久久婷婷综合缴情亚洲狠狠_| 少妇一晚三次一区二区三区 | 久久久性色精品国产免费观看| 欧美日韩亚洲精品瑜伽裤| 香港三日本三级少妇三级视频| 成人综合区另类小说区| 另类专区国产在线视频| 熟女人妻aⅴ一区二区三区60路| 久久久久女教师免费一区| 亚裔大战黑人老外av| 乱码人妻一区二区三区| 国产亚洲成av人片在线观看导航| 99久久久无码国产精品aaa| 久久天天躁狠狠躁夜夜躁app| 国产综合精品久久丫| 又大又长粗又爽又黄少妇视频| 国产成人亚洲综合色婷婷| 亚洲欧美日韩成人一区| 久久99精品久久久大学生| 亚洲日韩国产二区无码| 成年片色大黄全免费网站久久高潮 | 人妻互换免费中文字幕|