New thermosetting coatings using blocked carboxyl groups

Characteristics of blocked carboxylic acid compounds obtained by blocking carboxyl groups with alkyl vinyl ethers were studied, and new thermosetting coatings using blocked carboxyl groups and epoxide were also studied. Polybasic carboxylic acids were esterified with alkyl vinyl ethers to obtain blocked carboxylic acids having the hemiacetal ester moieties. Most of blocked carboxylic acids obtained were liquids and showed an excellent solubility in organic solvents and a good compatibility with epoxy resins. Although the blocked carboxylic acids were stable under ambient conditions, they could regenerate the corresponding carboxylic acids accompanied by the elimination of alkyl vinyl ethers by the thermal dissociation. They could be used as noble thermal latent hardeners. Curing of the blocked carboxyl groups and epoxide in the presence of relatively weak Lewis acid proceeded through a sequence of three-step reactions consisting of deblocking of alkyl vinyl ethers, esterification of epoxide, and the addition of alkyl vinyl ether to 2-hydroxyalkyl ester. The main product of the curing system was 2-acetalalkyl ester, but not 2-hydroxylalkyl ester. The new one-package thermosetting coatings using blocked carboxyl groups have been evaluated for use in the practical automotive and coil coatings line production. VOCs reduction, low-toxicity, and cost saving are satisfactory for the application of the systems. And the cured films of the coatings offered advantages in the high durability, the acid resistance and the soil resistance.     

Influence of the morphology on mechanical properties of toughened epoxies with CTBN

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RG-281碱性锌-镍合金工艺的研究

介绍了一种新型的RG-281碱性锌-镍合金工艺,并对镀液成分及操作条件进行了研究,确定了最佳的工艺条件为:氧化锌8~12g/L,氢氧化钠100~140g/L,RG-281配位剂80~100mL/L,RG-281镍补加剂8~12mL/L,RG-281光亮剂1~3mL/L,20~30℃,1~5A/dm2。对镀液性能和镀层性能进行了测试。锌-镍合金镀层的耐蚀性远大于纯锌镀层的。     

国内外无氰镀铜工艺研究进展

分析了无氰镀铜工艺能否应用于实际生产的关键因素。介绍了国内外常见无氰镀铜工艺,特别是碱性无氰镀铜工艺的研究现状、适用范围及特点。提出了一些无氰镀铜工艺开发的建议。     

UV固化PUA/EA核壳复合乳液的制备与性能

以自制的亲水性聚氨酯丙烯酸酯(PUA)预聚体为高分子乳化剂,与自制的环氧丙烯酸酯(EA)树脂充分混合后,采用相反转乳化法制备了可UV固化的具有不规则核壳结构的PUA/EA复合乳液。利用傅里叶变换红外光谱对水性PUA合成过程以及复合乳液UV固化前后进行了表征,表明合成得到了目标产物且UV固化良好。透射电镜(TEM)测试表明,复合乳液呈不规则的核壳结构,且EA含量不同时核壳结构也不同。讨论了羧基含量及中和度对复合乳液性能的影响,结果表明,随羧基含量的增加,乳液的平均粒径变小、外观越来越透明、黏度变大、贮存稳定性变好,UV固化后膜的硬度越来越高,吸水率先增加,后降低,又增加。随着中和度的增加,复合乳液的粒径逐渐减小,外观由不透明到透明又到不透明,稳定性先变好后变差,乳液的黏度和固化膜的吸水率都逐渐变大。     

凝胶法制备纳米氧化锆的工艺研究

采用凝胶法制备纳米氧化锆,先以酒石酸铵络合锆离子,再加入氨水使之与络合物充分混合,之后加入双氧水解除络合,生成氢氧化锆凝胶,待凝胶干燥后,高温下煅烧,再将煅烧后的产品和研磨助剂一起研磨,最终得到粒径为80nm的类球形的纳米氧化锆。     

Ti系催化剂对纤维级PET切片质量影响的研究

采用不同含量的Ti系催化剂制备了纺丝用聚对苯二甲酸乙二醇酯（PET）切片,通过乌氏黏度仪、差式扫描量热仪（DSC）、色差仪、气相色谱等仪器测试了影响PET切片质量的性能指标,包括特性黏度、熔点、色相（L值、b值、a值）、端羧基含量、二甘醇和间苯二甲酸（1PA）含量。结果表明,Ti系催化剂的含量对纺丝用PET切片的质量有很大影响,尤其是对色相b值的影响比较大。     

端羧基丁腈橡胶改性酚醛树脂的性能研究

采用端羧基丁腈橡胶（CTBN）对酚醛树脂进行改性,研究CTBN用量对改性酚醛树脂力学性能的影响。酚醛树脂的拉伸强度、断裂伸长率随CTBN用量的增大而呈上升趋势,当CTBN用量为10％时,拉伸强度、断裂伸长率达到最大值,并利用扫描电子显微镜（SEM）、傅立叶转换红外光谱（FTIR）和热重法（TGA）对改性前后酚醛树脂的结构和热性能进行分析。结果表明,CTBN与酚醛树脂之间发生了化学反应,并且改性酚醛树脂的热性能有所下降。     

油气田固井专用羧基丁苯胶乳的合成

以丁二烯、苯乙烯(St)为主要单体,引入不饱和羧酸、磺酸盐等作为功能性单体,采用复合乳化体系,以乳液聚合方式合成出油气田固井专用羧基丁苯胶乳。试验结果表明:最适宜的合成条件是w(复合乳化剂)=1.5%～2.0%、m(丁二烯)∶m(St)=(45～65)∶(55～35)、w(不饱和功能单体)=2.5%～3.5%(相对于总单体而言)、w(不饱和磺酸盐功能单体)=0.20%～1.00%、w(调节剂)=0.45%、m(烃)∶m(水)=100∶(120～130)、在(75±3)℃条件下聚合且w(过硫酸盐)=0.5%～0.6%;在最佳合成条件下制取的羧基丁苯胶乳,完全满足固井施工的要求。     

工程用聚丙烯腈纤维为基体的羧酸纤维的制备

采用断裂强度为12.26 cN/dtex、玻璃化转变温度高于250℃的工程用聚丙烯腈纤维(PAN-EF)为基体纤维,通过二甲基亚砜(DMSO)和氢氧化钠(NaOH)混合水解制备羧基含量(M_COOH)高且力学性能好的PAN-EF基羧酸纤维(PAN-EF-COOH),探讨了DMSO浓度、反应温度和反应时间对纤维水解效果的影响。结果表明:加入溶胀剂DMSO,可以降低PAN-EF在碱性条件下的水解难度;随着DMSO浓度增加、反应温度提高、反应时间延长,PAN-EF-COOH的M_COOH显著增大,但断裂强度逐渐降低;PAN-EF在NaOH质量分数0.1%、DMSO体积分数50%、反应温度120℃、反应时间2.5 h条件下水解,可以获得M_COOH较高且力学性能好的羧酸型纤维PAN-EF-COOH,纤维M_COOH为2.00 mmol/g、断裂强度为9.92 cN/dtex。