Studies On Synthesis And Properties Of Alkali-Soluble Hyperbranched Photosensitive Polysiloxane Oligomers

Photosensitive polysiloxane play a very important role in the field of photopolymerization materials for its excellent properties.Hyperbranched polymers have received considerable attentionin due to low viscosity and high reactive activity.alkali-soluble plolymers is more environment friendly meterials. The purpose of this paper is to design and synthesize a series of alkali-soluble hyperbranched photosensitive polysiloxane oligomers which has the all of the peculiarities of polysilaxane, polyurethane and polyester and characteristic of alkali-solubility, photosensitivity and hyperbranching and environmental protection. Also the relationship between properties and structure has been studied. And that can be theoretical and technical assistant for expanding UV-curing polysiloxanes application field.Four kinds of alkali-soluble hyperbranched photosensitive polysiloxane oligomers were synthesized. Their synthesis reaction and properities were also studied. The specific work was as follows:(1)Hyperbranched photosensitive polysiloxanes (APSUA, AHB,PSUA,AHB2PSUAA and AHB3PSUA) were synthesized with hydroxyl-terminated polysiloxane, isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA), acrylic acid(AA) and N' N'-tetraglycidyl-4,4'-diamino diphenyl methane (AG-80), HBP-OH(made in lab) as raw materials. The structures of the oligomers were characterized by 1H NMR, IR and GPC.The oligomers could dissolve in 1%Na2CO3 completely, and have good compatibility with acrylates monomers.The viscosity(236 MPa·s) of AHB3PSUA system is evidently lower than the viscosity(523 MPa·s)of AHB1PSUA(2) The photo-polymerization properties were researched by real time infrared spectroscopy (RT-IR) The effects of photoinitiator concentration, reactive monomers and structure of oligomers on the photosensitive property were investigated. The results showed that optimal concentration of the photoinitiator was 0.05%-0.07%(wt.%)The rate of double bond conversion is influenced by functionality and viscosity, therefore,it is important to choose proper monomers. The rate of double bond conversion of hyper branched oligomer AHB1PSUA, AHB2PSUA and AHB3PSUA are higher than APSUA. (3)The physical properties of UV-cured films, such as volumetric shrinkage, water resistance, chemical resistance,tensile strength, hardness, adhesion, property of photo-imaging, thermal resistance and Tg. The relationship between structure and property was systemically explored. The results show that the oligomers possess good water resistance and chemical resistance, excellent adhesion(Olevel) and hardness(6H), the volumetric shrinkage are all lower than 5%,the tensile strength (≥9.2 MPa)and stretch rate (≥29.9%) are both higher than the commercial resin OAK27(5.09MPa;9.48%),lost mass of AHB3PSUA was only 5.30% at 300℃(the lost mass of commercial resin OAK27 was 7.61% at 300℃,OAK12 was 25.79%). Also, all the synthesized oligomers are capable of securing accuracy of pattern,and could be used in solder resist ink widely.