Biodegradable sol–gel coatings of waterborne polyurethane/gelatin chemical hybrids

Gelatin from cold fish skin has strong mechanical properties and biodegradability. Cold fish gelatin was introduced into waterborne polyurethane (WPU) by covalent bonding to reinforce and render biodegradability of WPU. For this, gelatin was chemically modified with vinyltrimethoxysilane (VTMS) via the sol–gel type reactions and incorporated into hydroxyl ethyl acrylate (HEA) termini of WPU by UV curing. Covalent incorporations provided the hybrids with enhanced water resistance, hardness, glassy and rubbery state moduli, yield strength, and thermal resistance of soft segment along with significantly enhanced biodegradability both in trypsin solution and soil.     

Cellulose nanocomposites based on silane reinforced 3-butynoate-substituted zirconium-oxocluster copolymers: Mechanical,thermal and hydrophobic properties

Silica based cellulose nanocomposites obtained from (3-mercaptopropyl)trimethoxysilane or vinyltrimethoxysilane and 3-butynoate-substituted zirconium-oxoclusters were prepared and their surface morphology, wettability, and thermo-mechanical properties were studied. The composites showed a hydrophobic surface, high strength, and resistance to thermal degradation and aging; in comparison to the untreated paper they required a higher temperature to activate combustion and generated less heat during all thermal processes.     

不同有机官能团聚硅氧烷微球的制备与表征

以乳液聚合法制备粒径分布均匀、球形度良好的聚甲基硅氧烷微球(MPSQ)、聚乙烯基硅氧烷微球(VPSQ)、聚巯丙基硅氧烷微球(MPPSQ),采用SEM、DLS、FT-IR、XRD、TGA、接触角等测试技术对微球的微观形貌、粒径大小及分布、聚集态结构、耐热性、疏水性等进行了表征。研究结果表明,有机基团对微球的耐热性与疏水性有重要影响,MPSQ和VPSQ的耐热性优于MPPSQ,疏水性从高到低依次为:MPSQ>VPSQ>MPPSQ。聚硅氧烷微球的形成过程可能是单体首先在催化剂的作用下,水解生成硅醇,硅醇开始缩聚形成核,之后通过吸取溶液的硅醇,不断成长,最终形成微球,其中同时存在核生成和核生长,两过程相互竞争,哪个过程占优势取决于反应条件。提高反应温度,使得核生成占优势,最终生成的微球粒径变小,单分散性变差。     

聚乙烯基硅氧烷功能微球的制备研究

采用水解-缩聚两步法以乙烯基三甲氧基硅烷(VTMS)为原料,制备超细聚乙烯基硅氧烷微球,粒径为1~6μm,粒径分布较窄;就反应体系氨水浓度、油水比、反应温度等条件对微球形态、粒径大小及其分布的影响进行了研究。结果表明较优的反应条件为:氨水浓度在0.01%~0.16%之间,投料油水比(VTMS与去离子水的体积比)应小于1∶3;随着油水比的增大和反应体系中氨水浓度的降低,微球的粒径增大,分布变宽。     

VTMS等离子体聚合物的裂解色谱—质谱分析

本文应用裂解色谱-质谱(PGC/MS)分析和鉴定了乙烯基三甲基硅烷(VTMS)分别与Ar、N_2苯(Bz)混合体系等离子体聚合物的裂解碎片。质谱分析结果表明VTMS/Ar、VTMS/N_2以及VTMS/Bz三体系等离子体聚合物的裂解产物分别由8个、10个和16个主要碎片组成。根据PGC-MS结果讨论了VTMS等离子体聚合物的化学结构,并提出了VTMS等离子体聚合机理。     

有机高分子絮凝剂P(DMDAAC-VTMS)和P(DMDAAC-AM-VTMS)的合成及絮凝性能研究

采用水溶液自由基聚合方式,用复合引发剂引发聚合,得到了P（DMDAAC-VTMS）和P（DMDAAC-AM-VTMS）;探讨了BTMS的投料比对聚合物的特性粘度和水溶性的影响;并对这两种絮凝剂的除浊和脱色性能做了初步研究。实验中发现;VTMS的引入使P（DMDAAC-VTMS）和P（DMDAAC-AM-VYMS）的特性粘度分别比PDMDAAC和P（DMDAAC-AM）的特性粘度略微增大,但其水溶性变差;在絮凝性能方面,P（DMDAAC-VTMS）和P（DMDAAC-AM-VTMS）的除浊和脱色性能分别较PDMDAAC和P（DMDAAC-AM）有了提高。     

Nanoclay reinforced UV curable waterborne polyurethane hybrids

Waterborne polyurethane (PU)/clay nanocomposites were synthesized by incorporating the chemically modified clay into the main chain of PU by UV cure where modification was made using vinyltrimethoxysilane (VTMS) via sol–gel reaction. It was found that VTMS modified clay gave dual effects of multifunctional cross-link as well as reinforcing filler and significantly augmented hardness, tensile modulus and strength, rubbery modulus, gel content and swelling resistance, glass transition temperature and thermal stability of the waterborne PU.