half-hard rubber是什么意思

用法例句

The polyether polyol PTMG,polyester polyol PPG and 4,4 -diphenylmethane diisocyanate MDI as the main raw material,water foaming agent to do with the production of a new two-step method semi-rigid polyurethane.

本文采用聚醚多元醇PTMG、聚酯多元醇PPG与4,4'-二苯甲烷二异氰酸酯MDI为主要原料,以水做发泡剂,采用两步法制作一种新型聚氨酯半硬泡。