聚丙烯酸酯压敏胶的制备研究

采用丙烯酸丁酯、丙烯酸异辛酯、丙烯酸、醋酸乙烯酯等为原料,通过接枝聚合反应制备聚丙烯酸酯压敏胶。探讨了丙烯酸、醋酸乙烯酯及交联剂用量,引发剂的加入方式,胶液粘度对压敏胶性能的影响。结果表明,丙烯酸用量为3%,醋酸乙烯酯用量为23%,交联剂含量为2%,引发剂配制成溶液在聚合反应前3.5h内匀速滴入反应体系中,胶液黏度为2.3Pa·s时,压敏胶的综合性能最佳。     

水乳型压敏胶的研制及性能

研究了降解天然橡胶胶乳与丙烯酸甲酯的聚合 ,以 BPO-DMA为氧化还原引发剂 ,考察了反应温度 ,引发剂配比及乳化剂用量对单体转化率和接枝率的影响 ;用红外光谱对共聚物进行了表征并测试压敏胶性能。结果表明采用氧化还原引发剂可使聚合反应低温快速进行 ,过量还原剂起阻聚作用 ,采用复合乳化剂可提高反应速度和乳液稳定性。随丙烯酸丁酯用量增加 ,胶液的黏度增大 ;随降解深度的增加 ,接枝共聚产物粘接力学性能明显改善。     

溶剂型橡胶系压敏胶的研究

采用自交联工艺合成溶剂型橡胶系压敏胶,讨论了增粘树脂的用量、软化剂的用量、交联剂的用量、聚合反应温度、烘胶温度和烘胶时间对压敏胶性能的影响。实验表明,增粘树脂可以有效地提高压敏胶的初粘性和剥离强度,交联剂能够全面调节压敏胶的性能,适当的烘烤温度和烘烤时间有利于提高压敏胶的粘接性能。得出了最佳工艺条件为:增粘树脂与天然橡胶的质量比为701∶00,软化剂含量为20%,交联剂为0.4%,接枝共聚的温度为80℃。     

溶剂型聚丙烯酸酯压敏胶合成工艺的研究

以丙烯酸丁酯(BA)为软单体、丙烯酸甲酯(MA)为硬单体、2-丁酮(MEK)为溶剂和偶氮二异丁腈(AIBN)为引发剂,采用溶液聚合法合成了溶剂型聚丙烯酸酯类压敏胶(PSA)。考查了聚合反应温度、引发剂用量、软硬单体质量比和烘胶温度等因素对PSA性能的影响。结果表明:当聚合反应温度为80℃、w(AIBN)=0.4%(相对于总单体质量而言)、m(BA):m(MA)=2.5:1和烘胶温度为70℃时,PSA的综合性能相对较好。     

链转移剂对氟橡胶相对分子质量的影响

利用在聚合反应阶段对链转移剂的加入时间、加入量、链转移种类和总反应时间的控制,获得不同门尼黏度和相对分子质量的FKM26氟橡胶,并对不同门尼黏度的橡胶进行了性能研究.结果表明,通过对链转移剂的控制可以有效调节聚合物相对分子质量和门尼黏度,高门尼黏度的橡胶在耐油性和压缩形变性能均优于低门尼黏度的橡胶.     

UV-LED固化聚丙烯酸酯压敏胶的制备研究

以丙烯酸异辛酯、丙烯酸丁酯、丙烯酸羟基乙酯、丙烯酸羟基丙酯、GMA(甲基丙烯酸缩水甘油酯)和丙烯酸异冰片酯为共聚单体,BPO(过氧化二苯甲酰)为引发剂,NDM(正十二烷基硫醇)为链转移剂,采用本体聚合、两步法合成工艺(自由基聚合+逐步聚合)制备常温下低黏度、无溶剂的聚丙烯酸酯压敏胶,分别探讨了链转移剂正十二烷基硫醇含量、催化剂选择、功能单体ACMO(丙烯酰吗啉)加入量、胶层厚度和光引发剂配比对压敏胶性能的影响,以及压敏胶的耐高温性能。研究结果表明:当w(NDM)=1%、w(ACMO)=8%(相对预聚物总量而言)、催化剂选择对甲苯磺酸、胶层厚度为50μm时,压敏胶的环形初粘力达到30 N·(25 mm)~(-1),180°剥离强度为32 N·(25 mm)~(-1),持粘时间72 h。而且压敏胶有较好耐高温性,经历150℃、12 h的放置后,压敏胶180°剥离强度和持粘时间没有下降。     

耐热溶剂型丙烯酸酯压敏胶的制备与性能

在引发剂过氧化苯甲酰(BPO)的引发作用下合成溶剂型丙烯酸酯压敏胶(PSA),通过加入不同用量的黏度调节剂来改善压敏胶的耐热性能。采用差示扫描量热仪(DSC)及红外光谱对丙烯酸酯压敏胶进行了表征;通过制备压敏胶带,讨论了黏度调节剂对压敏胶180°剥离强度的影响;并运用旋转黏度计测试了其黏度在不同温度下的变化量。结果表明:反应时间为6.5 h,反应温度为78℃,溶剂乙酸乙酯(EAc)的用量与黏性单体质量一致时,所制备的溶剂型PSA性能较好。加入黏度调节剂后的压敏胶,玻璃化温度为-36.507℃左右,并增大了压敏胶的180°剥离强度,黏度调节剂用量为总质量的4%、6%时,压敏胶性能稳定,且耐热性优异。     

丙烯酸系压敏胶（续）

三、丙烯酸系压敏胶的生产方法溶剂型丙烯酸系压敏胶一般是通过自由基引发剂进行自由基聚合反应的。通过引发剂的分解、开始反应、链增长、链转移、链终止等符合基础理论的反应。前面讲到丙烯酸系压敏胶的分子设计是较复杂的。     

水性高速卷烟胶的制备

主要以聚乙酸乙烯酯为主体,PVB(聚乙烯醇缩丁醛)为辅助。采用共混法合成一种新的高速卷烟胶。加油酸和DOP混炼PVB胶片。加乳化剂制备水性PVB胶液。讨论了油酸的用量,反应时间、温度、pH值与水性PVB分散体性能的关系。将聚乙烯醇(PVA)溶于水中,加入甲醛进行缩聚反应;再加入非离子表面活性剂。以硫酸铵为引发剂,进行醋酸乙烯酯的聚合反应;最后共混聚乙酸乙烯酯和FVB,加入填料、助剂来完成卷烟胶的制备。结果表明：此法制得的高速卷烟胶具有较好的操作性和粘接性能。     

丙烯酸酯压敏胶的研制

采用丙烯酸丁酯、丙烯酸异辛酯、乙酸乙烯酯等为主要单体,通过接枝聚合反应制备溶剂型丙烯酸酯压敏胶,并对单体的组成、单体加入方式、引发剂用量、反应温度等进行了探讨。实验结果表明,在溶剂聚合的条件下,采用接枝聚合法的单体投入方式,能较好地控制反应进程;选择2种单体同时参与反应,优于一种单体的反应;引发剂用量为0.8%时,聚合物粘度较高;反应温度在80℃时,得到的压敏胶性能较好。     

链转移剂调控DMDAAC均聚物分子量

以工业级二甲基二烯丙基氯化铵(DMDAAC)为反应单体、甲酸钠或甲醇为链转移剂,选择过硫酸铵-亚硫酸氢钠氧化还原引发体系,采用水溶液聚合法得到分子量在800～9000的PDMDAAC.通过正交实验考察了单体质量分数、聚合温度、聚合时间、聚合体系pH值、引发剂用量、还原剂用量和链转移剂用量对聚合产物特性粘数和单体转化率的影响.研究了链转移剂对PDMDAAC分子量的调控作用及其用量对聚合物特性粘数和单体转化率的影响规律.     

Wettability and adhesion characteristics of photo-crosslinkable adhesives for thin silicon wafer

Acrylic pressure-sensitive adhesives (PSAs) have many applications in the processes of electronic industry. As the silicon wafers become thinner, the acrylic PSAs need to show proper adhesion and better wettability on the thin wafer. The acrylic copolymers were synthesized by solution polymerization of 2-ethylhexyl acrylate, ethyl acrylate, and acrylic acid with AIBN as an initiator. Photo-crosslinkable PSAs were synthesized by reaction of the acrylic copolymers with glycidyl methacrylate (GMA) and lauryl glycidyl ether (LGE). The adhesion performance of acrylic photo-crosslinkable PSAs was investigated based on wettability, probe tack, peel strength, cohesiveness, and viscoelastic properties. The adhesion characteristics varied significantly depending on the ratio of GMA to LGE in the photo-crosslinkable PSAs.     

Effect of naphthyl curing agent having thermally stable structure on properties of UV-cured pressure sensitive adhesive

Pressure sensitive adhesives (PSAs) with higher thermal stability were synthesized by crosslinking acrylic copolymer with naphthyl curing agent. The acrylic copolymer was synthesized for a base resin of PSAs by solution polymerization of 2-ethylhexyl acrylate, ethyl acrylate, and acrylic acid with N,N′-azobisisobutyronitrile as an initiator. The acrylic copolymer was further modified with glycidyl methacrylate to have the vinyl groups available for UV curing. Thermal stability of acrylic PSAs was improved noticeably with increasing naphthyl curing agent content and UV dose mainly due to the extensive formation of crosslinked structure in the polymer matrix. Although the peel strength decreased with UV curing of acrylic polymer, a proper balance between the thermal stability and the adhesion performance of PSAs was obtained by controlling the UV curing with naphthyl curing agent content and UV dose.     

Optical properties and adhesion performance of acrylic PSAs; influence of functionalized monomer and curing agent

Acrylic pressure–sensitive adhesives (PSAs) were synthesized by solution polymerization using zirconium carboxyethyl acrylate (ZrCEA) with methyl aziridine derivatives (MAZ) as a curing agent. The acrylic PSAs were characterized by Fourier transform-infrared spectroscopy and gel contents. The viscoelastic properties of the acrylic PSAs were determined using an advanced rheometric expansion system. The adhesion performance of the acrylic PSAs was determined by measuring the probe tack, peel strength, shear adhesion failure temperature, and holding power. The optical properties of the acrylic PSAs were evaluated by the transmittance and refractive index. The results show that the adhesion performance and optical properties of the acrylic PSAs are influenced by the ZrCEA and MAZ content.     

Effect of side chain on wettability and adhesion performance of acrylic pressure-sensitive adhesives on thin silicon wafer

Acrylic pressure-sensitive adhesives (PSAs) need to show proper adhesion and improved wettability on the silicon wafer as the wafer becomes thinner. The acrylic copolymers were synthesized by solution radical polymerization of 2-ethylhexyl acrylate, ethyl acrylate, and acrylic acid with AIBN as an initiator. Adhesion performance and wettability of acrylic PSAs were studied depending on the content of lauryl side chains and the degree of crosslinking. The introduction of lauryl side chain was characterized by Fourier transform infrared spectroscopy. The adhesion performance of acrylic PSAs having lauryl side chain was investigated using contact angle, wettability, probe tack, peel strength, and cohesiveness tests. The wettability of acrylic PSAs was improved significantly with increasing the content of lauryl side chain.     

Viscoelastic and adhesive properties of single‐component thermo‐resistant acrylic pressure sensitive adhesives

Poly(butyl acrylate‐vinyl acetate‐acrylic acid) based acrylic pressure sensitive adhesives (PSAs) were synthesized by solution polymerization for the fabrication of high performance pressure sensitive adhesive tapes. The synthesized PSAs have high shear strength and can be peeled off substrate without residues on the substrate at temperature up to 150°C. The PSAs synthesized in the present work are single‐component crosslinked and they can be used directly once synthesized, which is convenient for real applications compared to commercial multi‐component adhesives. The results demonstrated that the viscosity of the PSAs remained stable during prolonged storage. The effects of the preparation conditions such as initiator concentration, cross‐linker amount, organosiloxane monomer amount and tackifier resin on the polymer properties, such as glass transition temperature (T_g), molecular weight (M_w), surface energy and shear modulus, were studied, and the dependence of the adhesive properties on the polymer properties were also investigated. Crosslinking reactions showed a great improvement in the shear strength at high temperature. The addition of tackifier resin made peel strength increase compared to original PSAs because of the improvement of the adhesion strength. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40086.     

正交实验优化低分子质量聚丙烯酸钠合成工艺

采用水溶液聚合法,以丙烯酸为单体,过硫酸铵-亚硫酸氢钠为氧化还原引发体系,亚硫酸氢钠为链转移剂制得分子质量为3000～4000的聚丙烯酸钠。采用粘度法测得产物的黏均分子质量,对丙烯酸单体和聚丙烯酸钠聚合物的FTIR图谱进行了分析,通过正交实验研究了各因素对聚丙烯酸钠分子质量的影响趋势和程度。结果表明:影响最显著的因素为单体浓度,其次为反应温度,再次为引发剂用量,反应时间的影响最小。确定了最佳合成工艺条件:反应温度为45℃,反应时间为4h;丙烯酸单体质量分数为25%,引发剂过硫酸铵用量为单体质量的6%,链转移剂亚硫酸氢钠用量为单体质量的3%。FTIR谱图中不含碳碳双键,且有羧酸盐的特征峰出现,验证了聚合物的合成。该工艺节省能源,且制备方法简单,易于工业化生产。     

甲基丙烯酸甲酯—丙烯酸丁酯—丙烯酸三元溶液聚合研究Ⅱ.聚合物溶液性能影响因素研究

通过溶液聚合的方法合成了 Poly(MMA-BA-AA)三元共聚物溶液 ,研究了聚合体系中溶剂的种类及用量、单体组成、交联剂用量、引发剂用量、聚合温度对聚合物溶液性能的影响。实验结果表明 ,在良溶剂体系中 ,聚合物溶液的稳定性好、粘度小 ;随着 MMA、AA用量的减少 ,溶液的稳定性增大、粘度减小 ;引发剂用量增大 ,聚合温度升高 ,溶液的稳定性增大、粘度增大。     

高单体浓度下超低相对分子质量PAM的水溶液聚合

为合成高浓度水溶性胶黏剂,在高单体浓度下(40%),以过硫酸铵为引发剂,异丙醇为链转移剂,采用水溶液聚合法合成了超低相对分子质量聚丙烯酰胺。探讨了反应温度、链转移剂、引发剂等因素对聚合物相对分子质量的影响。EDTA能消除微量金属离子对相对分子质量波动的影响。在反应温度为80~90℃,引发剂浓度2~15×10-3mol/L,链转移剂浓度1~2.5mol/L时,所合成的聚丙烯酰胺相对分子质量为1.8~4.3×104。