聚乙烯醇接枝聚硅氧烷的制备与性能

Preparation and Properties of Polyvinyl Alcohol Grafted Polysiloxane

通过阴离子聚合向聚乙烯醇(PVA)中引入聚二甲基硅氧烷,制得以碳为主链、硅氧烷为侧链的亲水性共聚物(PVA-PDMS-OH)。与正硅酸四乙酯进行脱醇硫化制备了耐碱性的交联共聚物,提高了纯PVA-PDMS-OH的耐热和疏水的特性。使用PVA-PDMS-OH的硫化涂层覆盖改性聚对苯二甲酸乙二醇酯(PET)膜片表面,发现改性PET膜片透光率最高可提升至92.7%。将PVA-PDMS-OH添加到α,ω-二羟基聚二甲基硅氧烷(PDMS-OH)中制得共混硅橡胶。发现在共混硅橡胶中PVA-PDMS-OH的质量分数为10%时,共混硅橡胶的拉伸强度达到0.842 MPa,为纯PDMS-OH硅橡胶的6.7倍;断裂伸长率达到168.2%,为纯PDMS-OH硅橡胶的2.6倍。表明PVA-PDMS-OH可用于提高硅橡胶的拉伸强度和延伸率,改善其韧性,说明它在改进硅橡胶性能方面具有应用前景。

The copolymer(PVA-PDMS-OH)with carbon as main chain and siloxane as pendant group was prepared by introducing dimethylsiloxane into polyvinyl alcohol through anionic polymerization.The alkali-resistant cross-linked copolymer was obtained through dealcoholization vulcanization reaction between PVA-PDMS-OH and tetraethyl orthosilicate.The heat-resistant and hydrophobic properties of the pure PVA-PDMS-OH were improved by dealcoholization vulcanization reaction.The polyethylene terephthalate(PET)film was modified by the sulfide coating of PVA-PDMS-OH,and it is found that the light transmittance of the modified PET film can be increased to 92.7%.The PVA-PDMS-OH was added toα,ω-dihydroxy polydimethylsiloxane(PDMS-OH)to prepare a blended silicone rubber.It is found that when the addition amount of PVA-PDMS-OH in the blended silicone rubber is 10%,the tensile strength of the blended silicone rubber reaches 0.842 MPa,which is increased to 6.7 times that of the PDMS-OH silicone rubber;the elongation at break reaches 168.2%,which is increased to 2.6 times that of PDMS OH silicone rubber.The results indicate that the tensile strength,toughness and hardness of silicone rubber could be improved by adding PVA-PDMS-OH.It shows that PVA-PDMS-OH has application prospects in improving performance of silicone rubber.