改性超支化聚酯用于激光全息记录材料

Modification of Hyperbranched Polyesters for Holographic Recording

超支化聚合物的分子链之间无缠绕,堆砌疏松,小分子在其间容易扩散、迁移。因此,可能是制备激光全息记录材料的基体树脂。以偏苯三酸酐(TMA)、环氧氯丙烷(ECH)为原料,合成了末端为羟基的超支化聚酯;再分别以苯甲酸/DCC、苯甲酰氯/叔胺2种封端方式对超支化聚酯进行封端改性,制得了苯甲酰基团为末端的亲油性超支化聚酯;以改性的亲油性超支化聚酯为成膜树脂,多种(甲基)丙烯酸酯为光聚合反应的单体,配制了光致聚合物全息记录材料;研究了超支化聚酯的合成以及封端改性反应,比较了光聚合单体、光致聚合物薄膜厚度、曝光条件等对全息衍射效率的影响。用514.5nm的Ar+激光器,空间分辨率为2748线对/mm时,光致聚合物薄膜的灵敏度约为9.5m J/cm2,全息光栅衍射效率可达93%,具有较好的全息记录特性。

Hyperbranched polymers are loosely packed and lack with much less interehain tangling. They are potentially important components in holographic recording materials, because small molecules could transport easily inside. Hyperbranehed polyesters （HPE） with -OH as the terminal groups were synthesized from trimellitie anhydride （TMA） and epiehlorohydiin （ECH） by one-step reactions in milder conditions. The OH groups on the HPE were transformed into benzoate groups via two routs： modification with benzoic acid/DCC, or with benzoyl chloride. Photopolymers for holographic recording were prepared by combining HPE, acrylates photo-monomers and free radical photo initiator. The synthesis, medification and characterization of HPE were discussed. Effects of photo-monomers, such as AM, DAM, EA, BA, TFPMA, and the thickness of the photopolymer films, as well as the recording conditions on diffraction effieieneies were studied. The recording was performed with 514.5 nm of Ar^＋ laser at the spatial resolution of 2748 lp/mm. With TPGDA as the photomonomer, the recording sensitivity of the photopolymer was 9.5 mJ/cm^2 with diffraction efficiency about 93%.