王曉雯,何玉鳳,王榮民,王俊峰,李 琛
(生態(tài)環(huán)境相關(guān)高分子材料教育部重點(diǎn)實(shí)驗(yàn)室,甘肅省高分子材料重點(diǎn)實(shí)驗(yàn)室,西北師范大學(xué)化學(xué)化工學(xué)院,甘肅 蘭州 730070)
進(jìn)展與述評(píng)
功能性丙烯酸酯乳液的制備與應(yīng)用研究進(jìn)展
王曉雯,何玉鳳,王榮民,王俊峰,李 琛
(生態(tài)環(huán)境相關(guān)高分子材料教育部重點(diǎn)實(shí)驗(yàn)室,甘肅省高分子材料重點(diǎn)實(shí)驗(yàn)室,西北師范大學(xué)化學(xué)化工學(xué)院,甘肅 蘭州 730070)
介紹了核-殼乳液聚合、乳液互穿聚合物網(wǎng)絡(luò)、無皂乳液聚合、微乳液與細(xì)乳液聚合等方法與技術(shù)在制備功能性丙烯酸酯乳液中的應(yīng)用。闡述了有機(jī)硅、有機(jī)氟、聚氨酯、環(huán)氧樹脂等改性方法用于制備功能性丙烯酸乳液的研究進(jìn)展。詳細(xì)介紹了功能性丙烯酸乳液在功能涂料、膠黏劑、皮革涂飾劑、油墨等領(lǐng)域的應(yīng)用現(xiàn)狀,提出了功能性丙烯酸酯乳液的發(fā)展趨勢(shì):采用新的聚合技術(shù)、改性技術(shù)制備具有附加值高、性能優(yōu)異且環(huán)境友好的水性功能性乳液是今后丙烯酸酯乳液的主要發(fā)展方向。
功能性丙烯酸酯乳液;聚合技術(shù);聚合物改性;功能涂料;膠黏劑
丙烯酸酯共聚物乳液是(甲基)丙烯酸酯類與其它乙烯基酯類單體進(jìn)行乳液聚合的產(chǎn)物,具有優(yōu)異的抗老化、易成膜、耐油、耐酸堿等性能,價(jià)格低廉,合成工藝簡(jiǎn)單,符合環(huán)保要求,已被廣泛應(yīng)用于日用化工[1-2]、涂料成膜劑[3]、紡織印染黏合劑[4]、化學(xué)電源[5]、功能膜[6]、醫(yī)用高分子[7]、納米材料及水處理[8]等領(lǐng)域。但丙烯酸酯乳液自身也存在一些缺陷,如耐水性差、低溫易變脆、高溫易變黏失強(qiáng)等,因此,對(duì)丙烯酸酯乳液進(jìn)行改性及制備功能性丙烯酸酯乳液受到了關(guān)注。改性或制備功能性丙烯酸酯乳液可采用無皂乳液[9]、微乳液聚合[10]等方法,或通過乳液粒子設(shè)計(jì)和采用乳液聚合新工藝(如核殼乳液聚合[11]、互穿網(wǎng)絡(luò)技術(shù)[12]等方法)改善丙烯酸酯乳液的性能;其次,通過引進(jìn)有機(jī)硅、有機(jī)氟、聚氨酯、環(huán)氧樹脂等功能性基團(tuán),使丙烯酸酯乳液具有多功能或某種特定功能。本文主要是從聚合技術(shù)及功能性官能團(tuán)的引入兩方面綜述丙烯酸酯乳液的改性、功能化及性能和應(yīng)用的研究進(jìn)展。
為改善丙烯酸酯乳液的性能或功能化,可采用細(xì)乳液聚合、微乳液聚合、無皂乳液聚合、核-殼乳液聚合和乳液互穿聚合物網(wǎng)絡(luò)等聚合技術(shù)。
1.1 細(xì)乳液聚合
細(xì)乳液聚合是一種借助于乳化劑和助穩(wěn)定劑的作用,經(jīng)超聲乳化工藝,實(shí)現(xiàn)動(dòng)力學(xué)穩(wěn)定的亞微米級(jí)單體液滴分散體系的聚合,具有體系穩(wěn)定性高、產(chǎn)物膠乳的粒徑大且助乳化劑的用量易控制、聚合速率適中等特點(diǎn)。在穩(wěn)定的細(xì)乳液聚合中,乳膠粒的數(shù)目和尺寸主要由聚合前液滴的數(shù)目和尺寸決定,并在聚合過程中基本保持不變,而常規(guī)乳液由聚合過程的動(dòng)力學(xué)決定[13]。細(xì)乳液聚合中利用反應(yīng)型助乳化劑[14]和改性聚合物[15]代替?zhèn)鹘y(tǒng)助乳化劑可有效減少產(chǎn)品的后處理。
通過細(xì)乳液聚合制備的丙烯酸/聚氨酯復(fù)合乳液屈服應(yīng)力和應(yīng)變力[16]提高,所制備的納米級(jí)聚氨酯/甲基丙烯酸丁酯復(fù)合乳液粒子表現(xiàn)出良好的混溶性[17],含氟丙烯酸共聚物樹脂膜有更高的接觸角和更低的表面自由能,熱穩(wěn)定性得到很大提高[18]。
1.2 微乳液聚合
微乳液聚合技術(shù)可用于制備功能性丙烯酸酯乳液。微乳液聚合后乳膠粒直徑小,表面張力低,具有極好的滲透性、潤(rùn)濕性、流平性和流變性,可顯著提高涂膜的硬度、致密性、附著力、平滑性和光澤性[19]。Norakankorn等[20]制備的環(huán)氧功能化聚甲基丙基酸甲酯微乳液,隨GMA含量的增多其乳液固含量增加。采用微乳液聚合可制備有機(jī)硅改性的丙烯酸酯微乳液,所得乳膠膜的力學(xué)性能明顯提高,玻璃化溫度明顯降低,改善了丙烯酸樹脂的“熱黏冷脆”的現(xiàn)象,且水性無明顯變化[21]。在微乳液光聚合法中,硅烷偶聯(lián)劑的加入可改善和提高微乳液的耐水、耐酸和耐堿性能[22]。
1.3 無皂乳液聚合
在無皂乳液聚合體系中,膠粒主要通過結(jié)合在聚合物鏈或其端基上的離子基團(tuán)、親水基團(tuán)等得以穩(wěn)定。無皂乳液消除了親水表面活性劑的影響,避免了乳化劑存在下的隔離、吸水、滲出等作用,使聚合物具有較好的物理化學(xué)性能、力學(xué)性能和黏結(jié)性能,可顯著提高涂層的附著力、耐水性和耐溶劑性。無皂乳液廣泛地應(yīng)用于膠體粒子性質(zhì)的研究、水性涂料助劑、涂料、黏合劑等領(lǐng)域中。Wi等[23]先通過接枝聚合法制備了聚甲基丙烯酸大分子可逆加成-斷裂鏈轉(zhuǎn)移劑,用該兩親性接枝聚合物作為活性乳化劑與苯乙烯進(jìn)行無皂乳液聚合,制備了性能穩(wěn)定的乳液。殼層富含氟互穿網(wǎng)絡(luò)結(jié)構(gòu)的氟化聚丙烯酸脂乳液具有更好的熱穩(wěn)定性、高接觸角和低吸水性[24]。而穩(wěn)定性好、泛藍(lán)光的陽離子型無皂全氟丙烯酸酯共聚物乳液[25],當(dāng)全氟烷基乙基丙烯酸酯(FAEA)含量從1.2%增至5%時(shí),共聚物乳膠膜的表面自由能顯著降低,膠膜疏水功能明顯增強(qiáng)。將含氟丙烯酸酯無皂乳液與傳統(tǒng)乳液聚合得到的乳液及相應(yīng)的涂膜相比,無皂乳液的耐電解質(zhì)性能以及涂膜的耐水性、耐熱功能也顯著提高[26]。
1.4 核-殼乳液聚合
圖1 核殼結(jié)構(gòu)乳膠粒子形態(tài)
核-殼結(jié)構(gòu)聚合物由多種單體分段聚合而得,是在不改變?nèi)橐簡(jiǎn)误w組成的前提下改變?nèi)橐毫W拥慕Y(jié)構(gòu),從而提高乳液的性能,常見的核殼結(jié)構(gòu)乳膠粒子形態(tài)見圖1,典型結(jié)構(gòu)有等核殼(a)、反相核殼(b)、三明治(c)、雪人型結(jié)構(gòu)(d)、半球形(e)、草莓形(f)等結(jié)構(gòu)。由于乳膠粒子的內(nèi)部和外部分別富集不同的單體組分,核殼成分的極性及玻璃化轉(zhuǎn)變溫度的差異,使得乳液在成膜過程中表現(xiàn)出一些特殊功能,即軟殼使粒子之間容易擠壓融合,形成均勻致密的涂膜,使其具有較好的施工成膜性。乳膠粒的核殼結(jié)構(gòu)可顯著提高聚合物的耐磨、耐水及拉伸強(qiáng)度、黏接強(qiáng)度等[27]。
聚氨酯乳液可與甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸聚合,制得系列復(fù)合乳液,發(fā)現(xiàn)乳液粒徑隨丙烯酸酯/聚氨酯比例的增加而增大,半連續(xù)法比連續(xù)法得到的乳膠粒子粒徑小,乳液穩(wěn)定性好[28-29]。以親水性聚丙烯酸酯(PA)為殼、疏水性聚氨酯(PU)為核的乳膠粒是另一類PUA復(fù)合乳液[30]。有機(jī)硅改性丙烯酸酯納米乳液,乳液的膠膜具有較低的吸水率,較好的鈣離子穩(wěn)定性、機(jī)械穩(wěn)定性、耐熱性和稀釋穩(wěn)定性[31-32]。
1.5 乳液互穿聚合物網(wǎng)絡(luò)
乳液互穿聚合物網(wǎng)絡(luò)(interpenetrating polymer network,IPN)是兩種共混的聚合物分子鏈相互貫穿并以化學(xué)鍵方式各自交聯(lián)而形成的網(wǎng)絡(luò)結(jié)構(gòu)[33],IPN在溶劑中能夠溶脹,但不溶解;不發(fā)生蠕變和流動(dòng)。IPN的分子鏈各自交聯(lián)、相互貫穿、相互纏結(jié),存在強(qiáng)迫相容、界面互穿和協(xié)同效應(yīng),增強(qiáng)了乳液的穩(wěn)定性,改善了聚合物耐磨、耐水、耐候、耐污、防輻射、相溶性及物理力學(xué)性能[34],在聚合物的玻璃化轉(zhuǎn)變溫度及成膜性、流變性等方面表現(xiàn)出優(yōu)異的性能[35],可用作表面涂層、耐玷污劑、密封黏合劑、藥物釋放材料、阻尼材料、皮革涂飾劑、石刻防風(fēng)化材料等。Cheng等[36]成功制備了聚甲基丙烯酸(PMAA)與聚二甲基硅氧烷(PDMS)的IPN,將具有不同端基(如甲基丙烯酰氧基、丙烯酰胺基或甲基丙烯酰胺基)的聚二甲基硅氧烷(PDMS)溶于丙烯酸酯單體中,用紫外光引發(fā)聚合,可制得一系列的IPN[37]。用含氟丙烯酸酯共聚物乳液與丙烯酸丁酯、甲基丙烯酸甲酯、丙烯酸共聚物乳液混合,研究發(fā)現(xiàn)其復(fù)配膠膜的耐水功能接近含氟丙烯酸酯共聚物乳液膠膜[38]。核-殼互穿網(wǎng)絡(luò)氟功能化的聚丙烯酸乳液膜有更好的熱穩(wěn)定性、更高的接觸角以及更低的吸水能力[39]。以聚氨酯、丙烯酸酯和有機(jī)硅互穿網(wǎng)絡(luò)的雜合水分散體具備聚丙烯酸酯的高光澤、高硬度和優(yōu)異的顏料粒子親和性及聚氨酯的良好低溫性和優(yōu)異的力學(xué)性能[40]。
采用上述聚合方法,可制備出鏈鍛含硅、含氟等官能團(tuán)以及具有特殊性能的丙烯酸酯乳液。另外,不同的聚合技術(shù)可賦予丙烯酸酯乳膠粒子不同的形態(tài),從而賦予丙烯酸酯乳液更多的優(yōu)良性能,如自清潔、耐水、耐候、低成膜溫度、相溶性及物理機(jī)械等性能。
將丙烯酸酯乳液通過丙烯酸酯類單體與功能單體共聚,從而達(dá)到改性的目的,既可以改善丙烯酸酯乳液的性能,也能增加丙烯酸酯乳液的功能,即可得到功能性丙烯酸酯乳液。
2.1 有機(jī)硅改性
有機(jī)硅改性可分為物理共混改性和化學(xué)改性,丙烯酸酯乳液的有機(jī)硅改性是將有機(jī)硅分子鏈引入到丙烯酸酯中,改善丙烯酸酯熱黏冷脆、耐候性[41]、耐水性[42]等性能[43]。典型方法有縮聚法、自由基聚合法、硅氫加成法、互穿網(wǎng)絡(luò)法等。有機(jī)硅丙烯酸酯樹脂在干燥成膜時(shí),硅氧烷水解、縮聚[44-45],可在聚合物分子間及聚合物與基材間形成牢固交聯(lián)的立體網(wǎng)絡(luò),因而漆膜具有很強(qiáng)的耐水性和附著力,而且具有快干、光澤高、施工方便等優(yōu)點(diǎn)[46]。近年來,受到關(guān)注的硅烷偶聯(lián)劑有乙烯基三甲氧基(乙氧基)硅基烷、丙烯基三甲氧基硅烷、γ-(甲基丙烯酰氧基)-丙三甲氧基硅烷(KH570)等。聚硅氧烷分子主鏈結(jié)構(gòu)Si—O鍵能很高,因而具有優(yōu)良的溫變性、耐水性、耐玷污性、抗粉化性、透氣性和特殊的柔順性、化學(xué)惰性及低表面張力[47],但不足之處是不能常溫自干,成膜性較差,需高溫烘烤固化且價(jià)格較貴。
2.2 環(huán)氧樹脂改性
環(huán)氧樹脂是指在分子結(jié)構(gòu)中含有兩個(gè)或兩個(gè)以上環(huán)氧基,以脂肪族、芳香族等為骨架的一類熱固性樹脂。由于其中含有的環(huán)氧基、醚鍵、羥基以及苯環(huán)結(jié)構(gòu)等,使環(huán)氧樹脂具有優(yōu)良的附著力、良好的力學(xué)性能、高的黏合力、收縮率小、穩(wěn)定性好、電絕緣性優(yōu)良、良好的耐化學(xué)腐蝕等優(yōu)點(diǎn)[48-49]。丙烯酸與環(huán)氧樹脂制成的環(huán)氧丙烯酸酯(EA),可兼具二者優(yōu)良的性能[50-51]。環(huán)氧樹脂改性丙烯酸酯乳液一般采用以下2種方法。
(1)酯化改性法,即先用H+與環(huán)氧環(huán)中的氧原子作用生成“佯鹽”后,酸根離子再進(jìn)攻環(huán)氧環(huán)中的亞甲基,該過程也可以看做是丙烯酸樹脂中的羧基使環(huán)氧樹脂中的環(huán)氧基開環(huán)酯化,如圖2(a)。
(2)接枝共聚改性法,即丙烯酸樹脂中的羧基與環(huán)氧樹脂中的環(huán)氧基反應(yīng)發(fā)生交聯(lián),同時(shí)原環(huán)氧基團(tuán)發(fā)生反應(yīng)接枝在大分子鏈上。這類反應(yīng)可分為三種:①環(huán)氧樹脂中的環(huán)氧基團(tuán)與丙烯酸酯單體中的氨基、羧基、羥基等發(fā)生開環(huán)加成反應(yīng);②在環(huán)氧樹脂上引入不飽和雙鍵進(jìn)行共聚反應(yīng);③利用某些環(huán)氧樹脂本身特點(diǎn)進(jìn)行接枝共聚,如圖2(b)。
2.3 聚氨酯樹脂改性
由異氰酸酯和含兩個(gè)(或兩個(gè)以上)活潑氫(如羥基、氨基等)化合物聚合制得的聚氨酯(PU)樹脂分子結(jié)構(gòu)中含有氨酯鍵、醚鍵、酯鍵、脲鍵、脲基甲酸酯鍵等(圖3)。這使得鄰近分子鏈間有多重氫鍵,從而使線形聚合物在分子量相對(duì)低時(shí),具有較好的性能。聚氨酯涂膜豐滿、亮麗,具有優(yōu)異的耐腐性、附著力、耐化學(xué)品性、耐候性。但單一的PU乳液在穩(wěn)定性、自增稠性、固含量高及價(jià)格等方面不盡如人意。聚氨酯對(duì)水性丙烯酸樹脂進(jìn)行改性時(shí),可使聚氨酯的高耐磨性和良好的力學(xué)性能與丙烯酸良好的附著力和成膜性及較低的成本有機(jī)結(jié)合,從而使丙烯酸酯乳膠膜的功能及性能得到明顯改善[52]。聚氨酯改性丙烯酸酯乳液的方法主要有如下幾類:① PU和PA乳液物理共混改性;②帶雙鍵的氨基甲酸酯單體和丙烯酸酯共聚;③PU乳液作為種子進(jìn)行乳液聚合;④用溶劑型聚氨酯丙烯酸酯制備復(fù)合乳液(PUA),由于PU乳液和PA乳液是通過化學(xué)鍵連接在一起的,所以其相容性和成膜性比物理共混均得到了大大的提高。
2.4 有機(jī)氟改性
有機(jī)氟改性聚丙烯酸酯乳液可采用共混和共聚法,共混改性是將聚丙烯酸酯乳液調(diào)pH值到中性,并以一定的配比與含氟乳液混合,共聚乳液的制備是通過聚合使有機(jī)氟和丙烯酸酯以無規(guī)、接枝、嵌段或互穿網(wǎng)絡(luò)形式結(jié)合。含氟丙烯酸酯單體(圖4)可與多種不含氟單體發(fā)生乳液聚合,不同含氟單體的反應(yīng)活性順序?yàn)椋害?官能團(tuán)丙烯酸酯<甲級(jí)丙烯酸酯<丙烯酸酯,并且同系列單體中酯基團(tuán)與全氟鏈的間隔越長(zhǎng),單體的反應(yīng)活性越高。有機(jī)氟改性的丙烯酸酯乳液將全部或部分的具有氟碳樹脂的特性,表現(xiàn)為優(yōu)異的耐候性、耐久性、耐污性、耐化學(xué)性[53]、成膜性、防腐性、絕緣性、不易燃性、非黏附性、憎水性、防油性、耐紫外老化性能[54]、低溫柔韌性及低表面能等特點(diǎn)[55-56]。含氟丙烯酸乳液膜較丙烯酸乳液膜有更好的熱穩(wěn)定性[57-58]和更好的防護(hù)功能[59],并且雙氟化丙烯酸酯乳液,較單氟化丙烯酸酯乳液膜的表面性能特別是膜的接觸角有更好地提高[60]。
總之,丙烯酸酯乳液以有機(jī)硅、有機(jī)氟、聚氨酯、環(huán)氧樹脂等改性后,既能改善乳液的性能,也能拓展其功能。也可將幾種改性方法有機(jī)結(jié)合,對(duì)丙烯酸酯進(jìn)行復(fù)合改性,如將丙烯酸酯與環(huán)氧樹脂、聚氨酯三者結(jié)合,可制備具有三者優(yōu)點(diǎn)的功能性材料[61],丙烯酸酯-聚氨酯-有機(jī)氟互穿網(wǎng)絡(luò)聚合物乳液對(duì)紡織品、紙張、皮革、玻璃板有超強(qiáng)的附著力,也符合環(huán)保的要求[62]。
圖2 環(huán)氧樹脂改性聚丙烯酸酯乳液
圖3 聚氨酯樹脂分子鏈中的主要功能基團(tuán)
圖4 含氟丙烯酸酯單體分子結(jié)構(gòu)
3.1 功能涂料
采用不同聚合或改性方法制備的功能性丙烯酸乳液不但可以制備高性能涂料,也可以用于制備特殊功能的涂料。將有機(jī)硅和丙烯酸酯乳液聚合技術(shù)結(jié)合制得的硅丙乳液具有超耐候性,優(yōu)異的耐水、耐鹽霧、耐溫變、耐污染、抗顏料粉化及耐洗刷性能;有機(jī)硅含量達(dá)10%以上的改性硅丙乳液主要應(yīng)用于對(duì)耐候性能有特殊要求的建筑外墻涂料、工程機(jī)械漆以及作業(yè)環(huán)境惡劣的碼頭設(shè)備、海洋設(shè)施等的表面防蝕及裝飾。以苯乙烯和丙烯酸酯聚合物為殼的有機(jī)硅丙烯酸酯聚合物具有優(yōu)異的著色、抗碰撞等功能,可應(yīng)用于電子產(chǎn)品涂層[63]。有機(jī)硅改性丙烯酸酯乳液還可應(yīng)用于防污涂料[64]、夜光涂料[65]、防護(hù)涂料[66]等功能涂料[67]。
環(huán)氧改性丙烯酸酯乳液適于裝飾性要求特別高的場(chǎng)合,如塑料表面涂裝;因其具有良好的附著力、耐化學(xué)品、高強(qiáng)度、防腐性、價(jià)格低廉等優(yōu)點(diǎn),可用于木材、紙張、金屬等的涂裝[68],也可作為氨基丙烯酸涂料配套的中涂漆,如:罐頭內(nèi)壁涂料[69]、汽車防腐蝕涂料[70]、防火磁漆[71]等。環(huán)氧化丙烯酸酯紫外光固化涂料具有固化速度快,環(huán)保節(jié)能、涂層性能優(yōu)等特點(diǎn)[72]。PUA具有耐磨、耐腐蝕和光亮、柔軟有彈性、耐水性和力學(xué)性能好、耐候性佳等優(yōu)點(diǎn)[73],可應(yīng)用于耐水耐候性涂料[74]。
有機(jī)氟改性的丙烯酸酯聚合物涂料[75]的力學(xué)性能、耐候性[76]、抗污性、耐化學(xué)品性等十分優(yōu)良[77],被用于建筑、航空、橋梁、集裝箱、印刷、文物保護(hù)等領(lǐng)域。通過有機(jī)硅和有機(jī)氟復(fù)合改性的丙烯酸酯乳液可用于抗菌自清潔涂料,如:甲基丙烯酰氧丙基三甲氧基硅烷(MPS)為改性劑,對(duì)Fe-Ag摻雜納米二氧化鈦進(jìn)行表面改性,進(jìn)一步與丙烯酸及丙烯酸六氟丁酯共聚復(fù)合,制備具有核/殼結(jié)構(gòu)的乳膠粒應(yīng)用于涂料,所得內(nèi)墻涂料具有優(yōu)異的抗菌自清潔功能[78]。
作者成功制備了具有室溫自交聯(lián)功能的兩親性丙烯酸酯乳液[79],將不同類型的兩親性丙烯酸酯乳液與多孔的顏填料復(fù)合制備了水敏感智能呼吸涂料[80],此類功能涂料具有優(yōu)越的透水透氣性,可自動(dòng)調(diào)節(jié)室內(nèi)的濕度,具有較佳的增濕和降濕功能[81],其典型結(jié)構(gòu)如圖5所示。
3.2 膠黏劑
利用有機(jī)硅對(duì)丙烯酸酯樹脂進(jìn)行改性,可使聚丙烯酸酯分子鏈間發(fā)生交聯(lián)反應(yīng),材料的力學(xué)性能、耐熱性、耐溶劑性和耐水性大幅度提高,且黏接力強(qiáng),因此有機(jī)硅改性丙烯酸酯乳液可應(yīng)用于橡膠增強(qiáng)膠黏劑[83]。利用聚氨酯樹脂分子結(jié)構(gòu)可調(diào)性強(qiáng)、手感好、附著力強(qiáng)、耐磨、不熱黏冷脆等優(yōu)點(diǎn)[84],對(duì)丙烯酸樹脂改性后也可用作膠黏劑[85],用于透明型建筑及裝飾材料的黏結(jié),如夾層安全玻璃、防彈玻璃等。采用環(huán)氧樹脂改性丙烯酸酯乳液,在聚合物體系中引入了環(huán)氧基團(tuán),提高了樹脂的耐水性、耐沾污性、耐沖擊性和硬度等,可作為膠黏劑[86]。
有機(jī)硅、聚氨酯、環(huán)氧樹脂和有機(jī)氟改性丙烯酸酯乳液膠黏劑的另一研究方向,還可通過新型的乳液聚合方法開發(fā)高性能改性產(chǎn)品,使膠黏劑在耐寒性、耐熱性、耐候性、耐水性、黏接性和穩(wěn)定性方面有了很大的提高,應(yīng)用更廣泛。
圖5 水敏感智能呼吸涂料吸水后涂層保水示意圖[82]
3.3 其它領(lǐng)域的應(yīng)用
改性后丙烯酸酯乳液還在塑料增韌、皮革涂飾劑[87]、油墨[88-89]、反光板[90]、防污劑[91]、生物材料[92]得到應(yīng)用,以及在紙張印刷[93]、建筑及紡織品表面的拒水拒油處理[94]等領(lǐng)域有良好的應(yīng)用前景。
新型聚合技術(shù)可賦予聚合乳液粒子不同的形態(tài)與功能,而通過有機(jī)硅改性、有機(jī)氟改性、聚氨酯改性、環(huán)氧改性可在丙烯酸酯聚合物乳液中引入功能性官能團(tuán),賦予乳液粒子某些特定的功能,這些功能性丙烯酸酯乳液作為涂層與黏合劑,可廣泛應(yīng)用于建筑、電子、生物醫(yī)藥、紡織、印刷、航空航天等領(lǐng)域。另一方面,隨著人類生活質(zhì)量和環(huán)保意識(shí)的不斷提高,采用新的聚合技術(shù)、改性技術(shù)制備具有附加值高、性能優(yōu)異且環(huán)境友好的水性功能性乳液是今后丙烯酸酯乳液的主要發(fā)展方向。
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Preparation and app lication of functional acrylate latex
WANG Xiaowen,HE Yufeng,WANG Rongmin,WANG Junfeng,LI Chen
(Key Laboratory of Eco-Environment-Related Polymer Materials of M inistry of Education, Key Laboratory of Polymer Materials of Gansu Province, School of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China)
The application of methods and techniques, such as core-shell emulsion polymerization, latex interpenetrating polymer network, soap-free emulsion polymerization, micro-emulsion and mini-emulsion to preparing functional acrylate emulsion is reviewed. The progress of functional acrylate emulsion modified by organic silicon, organic fluoride, polyurethane and epoxy resin, is summarized. Moreover, the application of functional acrylate emulsion, such as functional coatings, adhesive, and leather finishing agents is also introduced. Finally, the development trend of functional acrylate emulsion is proposed. The water-based functional emulsion w ith high added value, excellent performance and environment-friendliness is the main development direction of the acrylate emulsion. Key words:functional acrylate emulsion;polymerization method;polymer modification;functional coatings;adhesive
O 63;TQ 31
A
1000–6613(2012)09–2011–08
2012-03-13;修改稿日期:2012-04-12。
國(guó)家自然科學(xué)基金(20964002)、甘肅省科技支撐計(jì)劃(1011GKCA017)及甘肅省屬高?;究蒲袠I(yè)務(wù)費(fèi)專項(xiàng)資金(2010-176)項(xiàng)目。
王曉雯(1986—),女,碩士,主要從事環(huán)境友好高分子的研究。聯(lián)系人:王榮民,教授,博士生導(dǎo)師。E-mail wangrm@ nwnu.edu.cn。