35results about How to "Moderate crosslink density" patented technology

The invention discloses a remoldable shape memory bismaleimide resin and an application thereof. 2-allylphenyl glycidyl ether is blended with terephthalic acid in acetonitrile, and an esterification reaction is carried out with a quaternary ammonium salt as a catalyst to obtain a bis(3-(2-allylphenoxy)-2-hydroxypropyl)terephthalate containing a reversible dynamic group; and the bis(3-(2-allylphenoxy)-2-hydroxypropyl)terephthalate is uniformly mixed with bismaleimide, and the obtained mixture is cured to obtain the remoldable shape memory bismaleimide resin. The remoldable shape memory bismaleimide resin prepared in the present invention has good shape memory performance, good heat resistance and good mechanical properties, and can be remolded under a hot pressing condition. The preparationmethod of the remoldable shape memory bismaleimide resin has the characteristics of wide sources of raw materials, and simple process, and the has remoldable shape memory bismaleimide resin broad application prospects in industrial fields of aerospace, space self-expanding structures, sensors and actuators.

The invention relates to a bismaleimide-based thermosetting shape memory resin with high deformation and a preparation method thereof. Comprise the following steps, bismaleimide and 1,6-hexanedithiol are added in m-cresol to form a solution; triethylamine is added dropwise in the solution, and N 2 Under protection and stirring conditions, react at room temperature to obtain linear oligomers; by mass, mix bismaleimide, linear oligomers and O, O´‑diallyl bisphenol A at a temperature of 130 ~ React at 150°C for 25-45 minutes to obtain a prepolymer; vacuum defoam the prepolymer at a temperature of 130-150°C, and then undergo curing and post-treatment to obtain a thermosetting shape memory resin based on bismaleimide. Compared with the prior art, the resin of the present invention has a large deformability, and its elongation at break at the programmed temperature is greater than 30%. In addition, the cured resin combines high glass transition temperature (>131°C) and initial decomposition temperature (>370°C), high toughness and outstanding shape memory properties.

The invention discloses a bismaleimide resin prepolymer and its application. The specific preparation is as follows: 2-allylphenyl glycidyl ether and terephthalic acid are blended in acetonitrile, and an esterification reaction occurs under the condition of a quaternary ammonium salt as a catalyst to obtain bis(3- (2‑allylphenoxy)‑2‑hydroxypropyl)terephthalate; bis(3‑(2‑allylphenoxy)‑2‑hydroxypropyl)terephthalate The formate ester and the bismaleimide are uniformly mixed to obtain a bismaleimide resin prepolymer, which is cured to obtain a remodelable bismaleimide resin. The remodelable bismaleimide resin prepared by the bismaleimide resin prepolymer of the present invention not only has excellent heat resistance and mechanical properties, but also can realize remodeling under hot pressing conditions, and is used in aerospace, It has broad application prospects in industrial fields such as transportation, electronic information, new energy, and electrical insulation.

The invention provides organosilicon joint sealing materials with low cost and high performance. A product prepared from the organosilicon joint sealing materials comprises the following components in proportion by weight: 100 alpha, omega-dicarboxylic dimethyl polysiloxane, 5 to 70 filler reinforcement agents, 0.5 to 12 crosslinking agents, 1 to 5 o coupling agents, 41 to 80 dimethyl polysiloxane, 1 to 8 deep-layer crosslinking accelerant and 6 to 14 tackifier, wherein the alpha, omega-dicarboxylic dimethyl polysiloxane and the filler reinforcement agents are added into a vacuum kneader, dehydrated and mixed to obtain base materials, the base materials are moved in a high-speed dispersator, and stirred and mixed with other components in a high-speed mode, and finally the crosslinking accelerants are added to carry out chemical reaction to obtain the joint sealing materials. Various raw materials used by the invention can be bought in the market; thereby the invention has low manufacturing cost, high performance in various aspects, low modulus, high extension percentage, normal temperature crosslinking, good bonding effect and sealing effect on cement and earth, good elastic restitution capability, embedding resistance, weather resistance and long service life.

The invention discloses a two-component silicone sealant for floodlights, which comprises independently packaged component A and component B, and the weight ratio of component A to component B is (5-10):1 and, in parts by weight, component A includes: 100 parts of hydroxyl-terminated polydimethylsiloxane, 2-10 parts of trimethyl-terminated polydimethylsiloxane, 80-150 parts of reinforcing filler, 10-40 parts of composite flame retardant; in parts by weight, component B includes: 30-50 parts of trimethyl-terminated polydimethylsiloxane, 3-10 parts of carbon black or titanium dioxide, and 10 parts of reinforcing filler -50 parts, 5-20 parts of silane crosslinking agent, 5-20 parts of silane coupling agent, 0.01-3 parts of composite synergistic condensation catalyst. The invention has the advantages of relatively uniform deep-layer curing speed and better bonding quality.

The invention discloses a prepolymer for remodeling bismaleimide resin and its application. The specific preparation is as follows: 2-allylphenyl glycidyl ether and adipic acid are blended in acetonitrile, and an esterification reaction occurs under the condition of a quaternary ammonium salt as a catalyst to obtain a bis(3-( 2‑allylphenoxy)‑2‑hydroxypropyl) adipate; then bis(3‑(2‑allylphenoxy)‑2‑hydroxypropyl) adipate was combined with bis The maleimide is uniformly mixed to obtain a prepolymer for a remodelable bismaleimide resin; the prepolymer is cured to obtain a remodelable shape memory bismaleimide resin. The remodelable shape memory bismaleimide resin prepared by the prepolymer of the remodelable bismaleimide resin of the present invention not only has good shape memory performance, heat resistance and mechanical properties, but also can be used under hot pressing conditions It can be reshaped under the environment, and has broad application prospects in the fields of aerospace, space self-deploying structures, sensors and actuators.